- Reactions of trans- and cis-Dichlorobis(benzonitrile)platinum(II) with Acetylacetonate and Benzoylacetonate Carbanions. Formation of N-Acetyl β-Ketoamine Complexes by the Acetyl Group Migration
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trans-Dichlorobis(benzonitrile)platinum(II) reacted with twice the molar amount of thallium(I) acetylacetonate and benzoylacetonate in dichloromethane at room temperature to afford mainly N-acetyl β-ketoamine chelates, (1a and 3a).This N,O-chelate structure of 1a was determined by X-ray analysis.Reactions of cis- gave C-acetyl and C-benzoyl β-ketoamine chelates, , together with other minor products.Formation of these β-ketoamine chelates is explained by the nucleophilic reactions of the β-diketonate carbanions at the coordinated cyanide carbon atom, followed by migration of the acetyl group or the methine proton of the nucleophiles onto the imino nitrogen atom formed during these reactions.In the presence of free β-diketones, migration of the acyl group was generally suppressed; this led to high yields of C-acyl complexes especially in reactions of cis-.In each case, the reaction proceeded with retention of the geometrical configuration around the central metal atom.The structures of other products, including a compound obtained by acid hydrolysis of 1a, were explored and discussed, based on IR and 1H NMR data.
- Uchiyama, Toshihiko,Takagi, Kazuhiko,Matsumoto, Keiji,Ooi, Shun'ichiro,Nakamura, Yukio,Kawaguchi, Shinichi
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- Crystalline and glassy phases in the ternary system Tl/Bi/Cl: Synthesis and crystal structures of the thallium(I) chloridobismutates(III) Tl3BiCl 6 and TlBi2Cl7
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Slow cooling of melts composed of TlCl and BiCl3 allows for the isolation of the compounds Tl3BiCl6 (1) and TlBi 2Cl7 (2). Compound 1 is formed by sublimation at 480 °C from the black melt of 3 TlCl + 1 BiCl3 as colourless crystals. The crystal structure determination (tetragonal, P42/m) consists of nearly regular octahedral [BiCl6]3- anions and two independent Tl+ cations, which have coordination number 8 in form of a slightly distorted cube and 10 in form of an Edshamar polyhedron, respectively. The structure is not isotypic with the recently reported naturally occurring form of Tl3BiCl6, the mineral steropesite. Compound 2 is obtained from a dark red melt of composition TlCl + 2 BiCl 3. On rapid cooling, this melt solidifies to a metasta-ble dark red glass which at ambient temperature crystallises to a light amber crystalline powder within some weeks. The structure of 2 was determined by powder diffraction (triclinic, P1). A distinct lone pair effect is present causing an irregular coordination on the two independent bismuth atoms. Taking Bi-Cl bonds up to 3.5 A into account, both bismuth atoms gain coordination number seven. 203T1 and 205Tl solid state NMR and XANES spectra on the Bi and Tl-LIII edges of both glassy and crystalline TlBi2Cl7 show that a close structural similarity exists between both forms. In contrast, the Raman spectra show distinct differences in the bands of the Bi-Cl vibrations region.
- Beck, Johannes,Benz, Sebastian
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- A study of the mechanochemical synthesis of TlCl nanoparticles by the method of dilution with the final product
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The kinetics of the solid-state mechanochemical synthesis of the nanosized product (TlCl) in the reaction 2NaCl + Tl2SO4 + zNa 2SO4 = (z + 1)Na2SO4 + 2TlCl was studied experimentlaly. The method used was based on the dilution of the initial mixture of powdered reagents (2NaCl + Tl2SO4) with another exchange reaction product (Na2SO4) at the optimum theoretically estimated z value, z = z= 11.25. Several special features of the development of this reaction were established. The parameters of the kinetic curve obtained for the mechanochemical synthesis of the desired product were compared with those of the kinetic curve determined theoretically for the model reaction KBr + TlCl + zKCl = (z + 1)KCl + TlBr with z = z 1 * = 13.5. This allowed us to experimentally estimate the mass transfer coefficient in a mechanochemical reactor by mobile milling bodies. This estimate was obtained for the first time. The dynamics of changes in the size of desired product nanoparticles depending on the time of mechanochemical activation in an AGO-2 ball planetary mill was studied. Pleiades Publishing, Inc., 2006.
- Urakaev,Shevchenko
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- Cationic dinuclear Pd-allyl-halide complexes with N-heterocyclic carbenes
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Reaction of the mononuclear N-heterocyclic carbene complexes (η 3-C3H5)Pd{C(N(R)CH)2}X (R = tBu, X = Cl, I (1a,b); R = C6H3-2,6- iPr2, X = Cl, I (2a,b)) wit
- Ding, Yuqiang,Goddard, Richard,Poerschke, Klaus-Richard
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- Raman spectroscopy study of products of reactions of zirconium and hafnium tetrachlorides with indium and thallium monochlorides
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Reactions of ZrCl4 and HfCl4 with InCl and TlCl accompanied by formation of several solid complex compounds were studied by the Raman spectroscopy method.
- Salyulev,Vovkotrub
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- Synthesis of and 2>
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Treatment of the dihalogeno derivatives 2> or with Al2Me6 gives the halogenomethyl complexes 2> (3a) - (3c) or (4a) - (4c) respectively.Dimers (3) react with PPh3 to give monomers (4).Complex (1b) reacts with LiMe to give (5).Reactions of (1) or (3b) with Tl(C5H5) give the 20-electron mixed bis(cyclopentadienyl) complexes .The structure of complex (7) (crystal A) has been determined by X-ray diffraction methods.By accident, the structure of the first crystal examined (B) contained (7) and the oxo complex trans-2> (8) in an ordered mixture with a 2:1 molar ratio.Crystal A is orthorhombic, space group Pna21 with Z = 4 in a unit cell of dimensions a = 9.370(4), b = 12.322(5), and c = 13.301(5) Angstroem.Crystal B is monoclinic, space group P21/a with Z = 4, (7), and 2, (8), in a unit cell of dimensions a = 32.569(9), b = 8.535(4), c = 9.482(5) Angstroem, and β = 93.33(3) deg.
- Jesus, Ernesto de,Miguel, Amelio Vazquez de,Royo, Pascual,Lanfredi, Anna Maria Manotti,Tiripicchio, Antonio
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- Cobalt half-sandwich, sandwich, and mixed sandwich complexes with soft tripodal ligands
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Reaction of sodium hydrotris(methimazolyl)borate (NaTmMe) with cobalt halides leads to the formation of paramagnetic pseudotetrahedral [Co(TmMe)X] (X = CI, Br, I), of which the bromide has been crystallographically characterized. Mas
- Dodds, Christopher A.,Lehmann, Mario-Alexander,Ojo, Jonathan F.,Reglinski, John,Spicer, Mark D.
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- New organobimetallic compounds containing catecholate and o-semiquinolate ligands
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New organobimetallic compounds CatSn[CpM(CO)n]2 (2-4) were obtained by the insertion of CatSn(II) (1) into the metal-metal bond of [CpM(CO)n]2 (Cat - 3,6-di-tert-butylcatecholate dianion; M = Fe (2), n = 2; M =
- Piskunov, Alexandr V.,Lado, Arina V.,Ilyakina, Ekaterina V.,Fukin, Georgii K.,Baranov, Evgenii V.,Cherkasov, Vladimir K.,Abakumov, Gleb A.
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- Electrophilic activation and the formation of an unusual Tl +/Cr3+ tetranuclear ion-complex adduct
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Reaction of TlPF6 with the Cr(iii) complex fac-[CrCl 3(NPN)] (NPN = bis(2-picolyl)phenyl phosphine) did not lead to precipitation of TlCl but rather to addition of the Tl+ cation to the CrCl3 moiety, which resulted in a pseudo-dimeric adduct which has an unusual tetranuclear centrosymmetric structure in the solid state.
- Liu, Shaofeng,Peloso, Riccardo,Pattacini, Roberto,Braunstein, Pierre
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- Dihydrobis(4-cyanopyrazol-1-yl)borate, [Bp4CN], a functionalized heteroscorpionate ligand with cross-linking potential
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Dihydrobis(4-cyanopyrazol-1-yl)borate, Bp4CN, the first example of a polypyrazolylborate ligand capable of intermolecular cross-linking, was synthesized. It forms chelates as a bidentate ligand but retains additional coordinating ability through the two 4-CN groups, leading to polymeric structures in M[Bp4CN]2 complexes or in the heteroleptic Co[Bp4CN][TpCy]. These -CN cross-links are broken by DMF, and the octahedral complexes M[Bp4CN]2(DMF)2 (M = Zn, Co) were structurally characterized. No -CN coordination was found in Rh[BP4CN](COD) or in the sterically hindered heteroleptic complex Co[Bp4CN][TpNp], which contained five-coordinate cobalt.
- Rheingold,Incarvito,Trofimenko
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- Pitzer Model Parameters for Sparingly Soluble Salts from Solubility Measurements: Thallium(I) Chloride in Aqueous Solutions of Ammonium Chloride, Rubidium Chloride and Caesium Chloride at 298.15 K
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Measurements are reported of the solubility of thallium(I) chloride in aqueous solutions of ammonium chloride, rubidium chloride and caesium chloride at 298.15 K at concentrations of added salt up to 4.0 mol kg-1.Pitzer model parameters for TlCl β(0) and β(1), were evaluated assuming CΦ = 0.These parameters can account satisfactorily for the ionic interactions between Tl(+) and Cl(-) without the need to assume ion association explicitly, thus simplifying the interpretation of the experimental data.Although the parameter α = 2, which is customarily used for a broad class of electrolytes, is found to be satisfactory for TlCl, larger values of α generally gave better fits to the experimental data.Mixture parameters, θ and ψ, relevant to the various mixed electrolytes are also reported.
- Khoo, Kean H.,Fernando, K. Rodney,Lim, Lee-Hoon
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- Semiconductor properties in an iodine-doped platinum(II) dinuclear complex
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The complex [{Pt(trpy)}2(μ-Me2dicyd)] [PF6]2, where trpy is 2,2′:6′,2″-terpyridine and Me2dicyd2- is 2,5-dimethyl-1,4-dicyanamidebenzene dianion, has been synthesized. Upon doping with iodi
- DeRosa,Al-Mutlaq,Crutchley
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- MIXED-LIGAND PALLADIUM(II) COMPLEXES CONTAINING O,O prime -CHELATED beta -DIKETONATE AND eta 3-CARBON-BONDED ETHYL 3-OXOBUTANOATE ANIONS. PREPARATION AND REACTIONS WITH SOME LEWIS BASES.
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Novel palladium(II) complexes in which anions of a beta -diketone and ethyl 3-oxobutanoate coordinate to the central metal atom by the O,O prime -chelation and the eta **3 carbon bonding, respectively, were prepared by the reactions of a dinuclear complex with thallium(I) beta -diketonates in benzene or acetone at room temperature. Reactions with Lewis bases such as triphenylphosphine, diethylamine, propylamine, and benzylamine were investigated. In almost all reactions, only the eta **3-carbon-bonded ester ligand was converted into a terminal-carbon-bonded one. The bonding modes for the ligands were determined by means of IR and **1H and **1**3C NMR spectroscopy.
- Yamada,Baba,Nakamura,Kawaguchi
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- Synthesis and crystal structure of pentavalent uranyl complexes. the remarkable stability of UO2X (X = I, SO3CF3) in non-aqueous solutions
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The reaction of [UO2I2(THF)3] with KC 5R5 (R = H, Me) or K2C8H8 in pyridine gave crystals of [{UO2(py)5}{KI 2(py)2}]∞
- Berthet, Jean-Claude,Siffredi, Gerald,Thuery, Pierre,Ephritikhine, Michel
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- Hydrothermal oxidation - Reduction methods for the preparation of pure and single crystalline alunites: Synthesis and characterization of a new series of vanadium jarosites
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Three new redox-based, hydrothermal, synthetic methods have been developed for the preparation of a new series of jarosites, AV3(OH)6(SO4)2 (A = Na+, K+, Rb+, TI+, and NH4+), in high purity and in single crystalline form. The V3+ jarosites have been characterized by single-crystal X-ray and elemental analysis, and by infrared and electronic absorption spectroscopy. The synthetic methods employed here represent a new approach for the preparation of the jarosite class of compounds, which for the past several decades, have been notoriously difficult to prepare in pure form. To demonstrate the impact of our new synthetic techniques on the magnetic properties of jarosites, the V3+ jarosites were also prepared according to the nonredox techniques used over the past 30 years. A comparative study of these samples and those prepared by our new synthetic methods reveals widely divergent magnetic properties, thus pointing to the importance of the new redox synthetic methods to future magnetism studies of jarosite compounds.
- Grohol, Daniel,Nocera, Daniel G.
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- Structural aspects of palladium and platinum complexes with chiral diphosphinoferrocenes relevant to the regio- and stereoselective copolymerization of CO with propene
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A series of chiral diphosphinoferrocene ligands 3a-i, derived from josiphos (=(2R)-1-[(1R)-1-(dicyclohexylphosphino)ethyl]-2-(diphenylphosphino) ferrocene, formerly called {(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl}dicycloxexylphosphine) where the electronic properties of the ligand are systematically varied, were prepared. X-Ray studies of five of these new ligands confirmed that these compounds display very similar conformations in the solid state and that no structural criteria could be found indicating the modified electronic properties. These ligands find application in the Pd-catalyzed highly regio- and stereoselective CO/propene copolymerization reaction, where the electronic properties of the ligand show a great impact on the catalyst activity. Coordination-chemical aspects of these diphosphinoferrocenes relevant to the CO/propene copolymerization reaction were addressed by the preparation and characterization of Pd- and Pt-complexes of the general formula [PdCl2(P-P)] (5), [PdMe2(P-P)] (6), [PdClMe(P-P)] (7), [PdMe(MeCN)(P-P)]PF6 (8), and [PtClMe(P-P)] (9) (P-P = chiral diphosphinoferrocene ligand (3a-h), four of which were characterized by X-ray crystallography.
- Gambs, Celine,Consiglio, Giambattista,Togni, Antonio
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- Synthesis and dehydrative condensation of square-planar mono- and dinuclear hydroxopalladium complexes with the hydrotris(3,5-diisopropylpyrazolyl)borato ligand (Tp(iPr)2), Tp(iPr)2(Py)Pd-OH, and (μ-OH)2{PdTp(iPr)2(H2O)}2
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Mono- and dinuclear hydroxopalladium complexes (k2-Tp(iPr2,X))(py)Pd-OH (1; X= H,Br) and (μ-OH)2{Pd(κ2-Tp(iPr2))(H2O)}2 (2) are prepared by base hydrolysis of the corresponding chloride complexes (κ2-Tp(iPr2,X))(py)Pd-Cl (3) and (μ-Cl)2{Pd(κ3-Tp(iPr2))}2 (4), respectively. Functionalization of the OH part in 1 is effected via dehydrative condensation with protic substrates (H-A) to give a series of substituted products, (κ2-Tp(iPr))(py)Pd-A (5), and treatment of the dinuclear complex 2 with excess acetic acid affords the mononuclear diacetato complex 6, (κ2-Tp(iPr2)-H)Pd(OAc)2(HOAc). Complexes 1-4 and 6 have been characterized crystallographically, and it is revealed that complexes 2 and 6 involve cyclic hydrogen-bonding interaction among the nitrogen atom of the pendent noncoordinated pyrazolyl group, the hydrogen atom in the protic part of the ligand (OH, AcOH), and, in the case of 2, an external water molecule.
- Akita, Munetaka,Miyaji, Taichi,Muroga, Nobuyuki,Mock-Knoblauch, Cordula,Adam, Waldemar,Hikichi, Shiro,Moro-oka, Yoshihiko
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- Unsymmetrical platinum(II) phosphido derivatives: Oxidation and reductive coupling processes involving platinum(III) complexes as intermediates
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Reaction of the trinuclear [NBu4]2[(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(RF)2] (1, RF = C6F5) with HCl results in the formation of the unusual anionic hexanuclear derivative [NBu4]2[{(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(μ-Cl)}2] (4, 96 e- skeleton) through the cleavage of two Pt-C6F5 bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu4][(R F)2Pt(μ-PPh2)2Pt(μ-PPh 2)2Pt(acac)] (5, 48 e- skeleton), which is oxidized by Ag+ to form the trinuclear compound [(RF) 2Pt(μ-PPh2)2Pt(μ-PPh2) 2Pt(acac)][ClO4] (6, 46 e- skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which displays a Pt-Pt bond. The reduction of 6 by [NBu4][BH4] gives back 5. The treatment of 6 with Br- (1:1 molar ratio) at room temperature gives a mixture of the isomers [(PPh2RF)(RF)Pt(μ-PPh 2)(μ-Br)Pt(μ-PPh2)2Pt(acac)], having Br trans to RF (7a) or Br cis to RF (7b), which are the result of PPh2/C6F5 reductive coupling. The treatment of 5 with I2 (1:1 molar ratio) yields the hexanuclear [{(PPh2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(μ-I)}2] (8.96 e- skeleton), which is easily transformed into the trinuclear compound [(PPh 2RF)(RF)Pt(μ-PPh2)(μ-I) Pt(μ-PPh2)2Pt(I)(PPh3)] (9, 48 e- skeleton). Reaction of [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(NCMe) 2] (10) with I2 at 213 K for short reaction times gives the trinuclear platinum derivative [(RF)2Pt(μ-PPh 2)2Pt(μ-PPh2)2Pt(I)2] (11, 46e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In particular, the 195Pt NMR analysis, carried out also by 19F-195Pt heteronuclear multiple-quantum coherence, revealed an unprecedented shielding of the 195Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has been carried out.
- Ara, Irene,Fornies, Juan,Fortuno, Consuelo,Ibanez, Susana,Martin, Antonio,Mastrorilli, Piero,Gallo, Vito
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- Activation Parameters of Bromoacetate-Thiosulfate Reaction in Ethylene Glycol-Water Mixtures
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The activation parameters for the reaction between bromoacetate (R) and S2O32- ions in water and aqueous mixtures of ethylene glycol (5-50percent) by weight) have been evaluated from the rate constants corresponding to zero ionic strength, at 1
- Biswas, Prasanta Kumar,Maula, Anwarul,Das, Mihir Nath
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- First-principles band-structure calculations and X-ray photoelectron spectroscopy studies of the electronic structure of TlPb2Cl 5
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We report on first-principles calculations of total and partial densities of states of atoms constituting TlPb2Cl5 using the full potential linearized augmented plane wave (FP-LAPW) method. The calculations reveal that the valence band of TlPb2Cl5 is dominated by contributions of the Cl 3p-like states, which contribute mainly at the top of the valence band with also significant contributions throughout the whole valence-band region. In addition, the bottom of the conduction band of TlPb 2Cl5 is composed mainly of contributions of the unoccupied Pb 6p-like states. Our FP-LAPW data indicate that the TlPb2Cl 5 compound is an indirect-gap material with band gap of 3.42 eV. The X-ray photoelectron core-level and valence-band spectra for pristine and Ar + ion-irradiated surfaces of a TlPb2Cl5 polycrystalline sample were measured. The measurements reveal high chemical stability and confirm experimentally the low hygroscopicity of TlPb 2Cl5 surface.
- Khyzhun,Bekenev,Denysyuk,Parasyuk,Fedorchuk
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- Polysulfonylamines. CLXIV. Crystal structures of metal Di(methanesulfonyl)amides. 13. Dithallium tris(dimesylamido-N)argentate: A two-dimensional coordination polymer
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The complex salt Tl2[Ag{N(SO2Me)2} 3] (monoclinic, space group P21/n, Z′ = 1) was obtained by serendipity. Its layer structure displays two unprecedented characteristics, viz. one (MeSO2)2N- ion that strongly deviates from the C2-symmetric standard conformation of this species and approximates to mirror symmetry, and a tris(dimesylamido)argentate anion featuring a trigonal-planar AgN3 core with Ag-N bond lengths of 225.6(6), 226.0(6), 236.3(6)pm and N-Ag-N angles in accordance with VSEPR concepts [149.8(2) vs. 102.8(2) and 107.3(2)°]. The independent thallium ions are coordinated by the complex anions to form monolayer substructures, in which Tl(1) attains an O6 and Tl(2) an O5 environment; the monolayers are associated into bilayers via one independent set of Tl(2)-O bonds that concomitantly raise the coordination number for Tl(2) to six. Both TlO6 polyhedra may be viewed as extremely distorted octahedra reflecting the stereochemical activity of the 6s lone pair of electrons. The two-dimensional Ag-N/Tl-O bonding system is reinforced by a three-dimensional network of weak C-H...O hydrogen bonds.
- Latorre, Violeta,Jones, Peter G.,Moers, Oliver,Blaschette, Armand
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- Synthesis and structure of rhodium complexes with monoanionic carborane ligand
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(Rhodacarborane)halide complexes [(η-9-SMe2-7,8-C2B9H10)RhX2]2 (4a: X = Cl; 4b: X = Br; 4c: X = I), which are analogous to [Cp*RhX2]2, were synthesized by reaction of
- Kudinov, Alexander R,Perekalin, Dmitry S,Petrovskii, Pavel V,Lyssenko, Konstantin A,Grintselev-Knyazev, Gennadii V,Starikova, Zoya A
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- Cobalt tris(mercaptoimidazolyl)borate complexes: Synthetic studies and the structure of the first cobaltaboratrane
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The paramagnetic complexes (TmtBu)CoX (X = Cl, Br, I) have been readily prepared and structurally characterized and provide a convenient entry into cobalt(II) tris(mercaptoimidazolyl)borate chemistry. A number of derivatives, including mononuclear triphenylphosphine adducts [(Tm tBu)Co(PPh3)]X and dinuclear compounds [Co 2(TmtBu)2X]Y, have been prepared in order to ascertain whether cobalt is a reliable surrogate for zinc in biological systems, particularly in sulfur-rich coordination environments. The structure of the first cobaltaboratrane is also reported.
- Mihalcik, David J.,White, Jennifer L.,Tanski, Joseph M.,Zakharov, Lev N.,Yap, Glenn P.A.,Incarvito, Christopher D.,Rheingold, Arnold L.,Rabinovich, Daniel
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- Phase equilibria and some properties of solid solutions in the Tl 5Te3-Tl9BiTe6-Tl5Te 2Cl system
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Phase equilibria in the Tl5Te3-Tl9BiTe6- Tl5Te2Cl system were studied by differential thermal analysis (DTA), X-ray powder diffraction, and measurements of microhardness and also emf of concentration circuits with reference to a thallium electrode. A number of polythermal sections, the isothermal sections of the phase diagram at 760 and 800 K, and projections of the liquidus and solidus surfaces were constructed. It was shown that the system is characterized by the formation of unlimited solid solutions with the Tl5Te3 structure. The concentration dependences of the crystal lattice parameters, microhardness, and emf in the solid solutions were described.
- Babanly,Askerova,Aliev,Babanly
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- Supersilyltrielanes R*nEHal3-n, (E = Triel, R* = SitBu3): Syntheses, characterization, reactions, structures [1]
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Water- and oxygen-sensitive compounds R*EHal2?D, R*EHal2 and R*2EHal (R* = SitBu3; E = B, Al, Ga, In, Tl; Hal = F, Cl, Br, I; D = OR2, NR3) have been synthesized by reaction of EHal3 with NaR* in the absence or presence of donors as well as by substitution of D, Hal or R* by other substituents, or by reaction of R*2E-ER*2 (E = Al, In) with I2, H2, AgF2 or HBr. Thermal decomposition of the compounds in solution or in the gas phase leads to elimination of D from R*EHal2?D, or of R*Hal from R*EHal2 and R*2EHal, respectively. The dihalides R*EHal2 act as Lewis acids with respect to donors OR2 or NR3 (formation of adducts R*EHal2?D), the monohalides R*2EHal as Lewis bases with respect to acceptors EHal3 (formation of R*2E+ EHal4-). Dehalogenations of R*2EHal and R*EHal2 with alkali metals or NaR* leads to compounds R*4E2 (E = Al, In, Tl), R*3E2? (E = Al, Ga), R*4E3? (E = Al, Ga), R*4E4 (E = Al, Ga), R*6Ga8, R*8In12, (R*2B-), R*2Al-, R*3Ga2-, R*4Ga3-, R*4Ga42-, R*4Tl3Cl, or R*6Tl6Cl2. The structures of R*BBr2?Py, R* AlBr2?NEtMe2, (R*AlClOBu)2, R*2BF as well as R*2ECl (E = B, Al, Ga, Tl) have been determined by X-ray structure analyses.
- Wiberg, Nils,Amelunxen, Kerstin,Blank, Thomas,Lerner, Hans-Wolfram,Polborn, Kurt,N?th, Heinrich,Littger, Ralf,Rackl, Manfred,Schmidt-Amelunxen, Martin,Schwenk-Kircher, Holger,Warchold, Markus
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- Cationic chromium (III) alkyls as olefin polymerization catalysts
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The authors describe a number of cationic chromium(III) alkyls, some of which are catalysts for the polymerization of ethylene and propene. Experimental results indicate that cationic metal sites may be responsible for the catalysis. The positive charge of such complexes may be crucial for binding of the electron-rich olefin to a metal center that has little propensity for back-bonding.
- Thomas,Theopold
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- Kinetics of Thallium Dissolution in Aqueous Solutions of Hydrochloric Acid
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Abstract: Potentiometry is used to study the kinetics of electrochemical oxidation and reduction of thallium in aqueous solutions of hydrochloric acid. Kinetic parameters are calculated to characterize the mechanism of the electro-oxidation of thallium: c
- Sarbaeva,Tuleshova, E. Zh.,Zhylysbaeva,Sarbaeva
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- Gallium and indium arsanido metalates: Compounds derived from the zinc blende and wurtzite structure
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The reaction of InCl3 with LiAstBu2 in THF at -78°C gives the indium arsenide Cl2InAstBu2 (1), which is dimer in solution and solid state. The corresponding reaction of InCl3 with Li2AstBu leads to the metalate [Li(THF)4]2[(InCl)4(InCl2) 2(AstBu)6] (2). The arsanido metalate [Li(THF)4]2[(GaCl2)6(As tBu)4] · THF (3 · THF) could be obtained by treatment of GaCl3 with Li2AstBu in the molar ratio 6:4. A comparable reaction with TlCl3 and LiAsR2 or LiPR2, respectively, was not successful because of the oxidation potential of TlCl3. The reaction mixture of TlCl3 and LiPPh2 for example gives TlCl and Ph2P-PPh2 (4) as redox products. The octaarsane [As(AstBu)3]2 (5) can be obtained by the treatment of tBuAs(SiMe3)2 with TlCl3 in THF. 1-5 were characterized by NMR, IR and MS techniques. The X-ray analyses of 2 and 3·THF show that 2 can be derived from the wurtzite structure while the zinc blende structure is the model for 3 with a adamantane-like dianion [(GaCl2)6(AstBu)4]2-.
- Dashti-Mommertz, Anahita,Neumueller, Bernhard
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- Investigation of the C-H activation potential of [hydrotris(1H-pyrazolato-κN1)borato(1-)]iridium (IrTpx) fragments featuring aromatic substituents x at the 3-position of the pyrazole rings
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A series of pyrazole-substituted [hydrotris(1H-pyrazolato-κN1)borato(1-)]iridium complexes of the general composition [Ir(Tpx)(olefin)2] (Tpx = TpPh and TpTh) and their capability to activate C-H bonds is presented. As a test reaction, the double C-H activation of cyclic-ether substrates leading to the corresponding Fischer carbene complexes was chosen. Under the reaction conditions employed, the parent compound [Ir(TpPh)(ethene)2] was not isolable; instead, (OC-6-25)-[Ir(TpPhκCPh,κ3N, N′,N″)(ethyl)(η2-ethene)] (1) was formed diastereoselectively. Upon further heating, 1 could be converted exclusively to (OC-6-24)-[Ir(TpPhκ2CPh,C Ph,κ3N,N′,N″)(η2- ethene)] (2). Complex 1, but not 2, reacted with THF to give (OC-6-35)-[Ir(TpPhκ3N,N′,N″)H (dihydrofuran-2(3H)-ylidene)] (3), a cyclic Fischer carbene formed by double C-H activation of THF. Accordingly, complexes of the general formula [Ir(Tpx)(butadiene)] (see 4-6; butadiene = buta-1,3-diene, 2-methylbuta-1,3-diene (isoprene), 2,3-dimethylbuta-1,3-diene) reacted with THF to yield 3 or the related derivative 9. The reaction rate was strongly dependent on the steric demand of the butadiene ligand and the nature of the substituent at the 3-position of the pyrazole rings.
- Slugovc, Christian,Mereiter, Kurt,Trofimenko, Swiatoslaw,Carmona, Ernesto
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Read Online
- Thiolato-bridged linear trinuclear platinum complexes [Pt 3(μ-SR)4(dppm)2]2+
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Thiolato-bridged tri- and dinuclear platinum complexes of the types [Pt3(μ-SR)4(dppm)2]2+ (1) and [Pt2(μ-ER)2(dppm)2]2+ (2) (E=S or Se; R=alkyl or aryl; dppm=bis(diphenylphosphino)methane) have been prepared using the mononuclear precursors [Pt(ER)2(dppm)]. The complexes have been characterized by NMR (1H, 13C, 31P, 195Pt), FT-IR and FAB mass spectral data. The structure of [Pt 3(μ-SC6H4CH3-4) 4(dppm)2][CF3SO3] 2·6CH2Cl2 (1d), has been established through X-ray crystallography, revealing a zig-zag arrangement of the three coordination spheres around the platinum atoms.
- Singhal, Anshu,Jain, Vimal K.,Klein, Axel,Niemeyer, Mark,Kaim, Wolfgang
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Read Online
- Binding of Gold(III) from Solutions with Thallium(I) Dibutyldithiocarbamate: Synthesis, Supramolecular Self-Organization, and Thermal Behavior of the Complex ([Au{S2CN(C4H9)2}2][TlCl4])n
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The binding of gold(III) from solution in a 2 M HCl with thallium(I) dibutyl dithiocarbamate leads to the formation of ion-polymeric complex ([Au{S2CN(C4H9)2}2][TlCl4])n, which was studied by (13С, 15N) MAS NMR spectroscopy and X-ray diffraction analysis. In the complex comprising the nonequivalent cations [Au{S2CN(C4H9)2}2]+ (A and B) and anions [TlCl4]–, the supramolecular self-assembly is provided by secondary bonds Au···S and S···Cl. The former are involved in the formation of isomeric binuclear cations [А···А] and [В···В] that build the (···[А···А]···[В···В]···)n polymeric chain; the latter selectively combine the thallium(III) anions and the dimeric cations. Thermolysis of the complex is accompanied by gold recovery and release of TlCl.
- Ivanov,Bredyuk,Loseva
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p. 1470 - 1477
(2018/09/11)
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- Insertion of allenes into the Pd-C bond of ortho-palladated primary arylamines of biological relevance: Phenethylamine, phentermine, (l)-Phenylalanine methyl ester, and (l)-tryptophan methyl ester. Synthesis of tetrahydro-3-benzazepines and their salts
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The previously reported ortho-metalated complexes [Pd(C,N-ArCH 2CRR'NH2-2)(μ-X)]2 derived from phenethylamine (Ar = C6H4, R = R' = H, X = Cl, Br), phentermine (Ar = C6H4, R = R' = Me, X = Cl), (l)-phenylalanine methyl ester (Ar = C6H4, R = H, R' = CO2Me, X = Cl, Br)), and (l)-tryptophan methyl ester (Ar = C 8H5N, R = H, R' = CO2Me, X = Cl) react with various allenes to give (1) the corresponding η3-allyl complexes derived from the insertion of one molecule of the allene into the Pd-C bond, the formation of which has been studied by DFT using a model complex, or (2) Pd(0) and the tetrahydro-3-benzazepinium salts, resulting from the decomposition of the above mentioned η3-allyl complexes, containing an exocyclic double bond, which, subsequently, react with a base to afford the corresponding benzazepines. The regiochemistry of these decomposition reactions has been studied and compared with that described for similar processes involving five-membered palladacycles. The crystal structures of the salts of some benzazepines and one isoquinoline, derived from a five-membered palladacycle, have been determined by X-ray diffraction studies.
- Garcia-Lopez, Jose-Antonio,Saura-Llamas, Isabel,McGrady, John E.,Bautista, Delia,Vicente, Jose
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p. 8333 - 8347
(2013/02/22)
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- Syntheses, dynamic behaviour and theoretical studies of [(Piperidinomethyl)silyl]methyl-cyclopalladated dimetallic complexes
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The cationic complex [Pd{CH2SiPh2(CH 2NC5H10)-κ2C,N}(NCMe) 2]BF4 (CH2NC5H10 = piperidinomethyl) is obtained from the reaction of [Pd{CH2SiPh 2(CH2NC5H10)-κ2C,N} (μ-Cl)]2 with TlBF4 in the presence of NCMe. It reacts with KO2CCH3 leading to the dimetallic complex [Pd{CH 2SiPh2(CH2NC5H10)- κ2C,N}(μ-O2CCH3-κO:κ'O)] 2, which exists only as the transoid isomer in solution. A dynamic process due to inversion of the acetato bridges is detected by variable-temperature 1H NMR spectroscopy. The reaction of the same parent complex with Kdmpz (dmpz = dimethylpyrazolate) leads to the dinuclear complex [Pd{CH2SiPh2(CH2NC5H 10)-κ2C,N}(μ-dmpz-κN:κ'N)] 2, which in solution exists as a mixture of cisoid and transoid isomers, but no inversion of the bridging pyrazolato groups has been observed. The reaction between equimolar amounts of these two complexes in CH 2Cl2 affords low yields of the expected mixed acetato/pyrazolato-bridged complex [Pd2{CH2SiPh 2(CH2NC5H10)-κ2C,N} 2(μ-O2CCH3-κO:κ'O)(μ-dmpz- κN:κ'N)]. The mixed chlorido-pyrazolato-bridged complex [Pd 2{CH2SiPh2(CH2NC5H 10)-κ2C,N}2(μ-Cl)(μ-dmpz-κN: κ'N)] is obtained by mixing equimolar amounts of the parent dichlorido- and bis(dimethylpyrazolato)-bridged dinuclear complexes, and exhibits a dynamic process in solution corresponding to the inversion of the bridges. Only the cisoid isomers are detected for both dimetallic complexes with mixed bridging ligands. The experimental findings of the preferred transoid or cisoid structure in these dinuclear Pd complexes were supported by quantum chemical calculations. The nature of the bridging ligands determines both the presence of transoid or cisoid isomers and the rigidity in solution of dimetallic complexes containing palladacycles with the [(piperidinomethyl)silyl]methyl ligand. Copyright
- Colquhoun, Victoria P.,Schildbach, Daniel,Martin-Romo, Raquel,Strohmann, Carsten,Villafane, Fernando
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p. 3427 - 3434
(2012/09/08)
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- Actinide metals with multiple bonds to carbon: Synthesis, characterization, and reactivity of U(IV) and Th(IV) bis(iminophosphorano)methandiide pincer carbene complexes
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Treatment of ThCl4(DME)2 or UCl4 with 1 equiv of dilithiumbis(iminophosphorano) methandiide, [Li2C(Ph 2P=NSiMe3)2] (1), afforded the chloro actinide carbene complexes [Cl2M(C(Ph2P=NSiMe3) 2)] (2 (M = Th) and 3 (M = U)) in situ. Stable PCP metal-carbene complexes [Cp2Th(C(Ph2P=NSiMe3)2)] (4), [Cp2U(C(Ph2P=NSiMe3)2)] (5), [TpTh(C(Ph2P=NSiMe3)2)Cl] (6), and [TpU(C(Ph2P=NSiMe3)2)Cl] (7) were generated from 2 or 3 by further reaction with 2 equiv of thallium(I) cyclopentadienide (CpTl) in THF to yield 4 or 5 or with 1 equiv of potassium hydrotris(pyrazol-1- yl) borate (TpK) also in THF to give 6 or 7, respectively. The derivative complexes were isolated, and their crystal structures were determined by X-ray diffraction. All of these U (or Th)-carbene complexes (4-7) possess a very short M (Th or U)=carbene bond with evidence for multiple bond character. Gaussian 03 DFT calculations indicate that the M=C double bond is constructed by interaction of the 5f and 6d orbitals of the actinide metal with carbene 2p orbitals of both π and σ character. Complex 3 reacted with acetonitrile or benzonitrile to cyclo-add C≡N to the U=carbon double bond, thereby forming a new C-C bond in a new chelated quadridentate ligand in the bridged dimetallic complexes (9 and 10). A single carbon-U bond is retained. The newly coordinated uranium complex dimerizes with one equivalent of unconverted 3 using two chlorides and the newly formed imine derived from the nitrile as three connecting bridges. In addition, a new crystal structure of [CpUCl 3(THF)2] (8) was determined by X-ray diffraction.
- Ma, Guibin,Ferguson, Michael J.,McDonald, Robert,Cavell, Ronald G.
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p. 6500 - 6508
(2011/08/07)
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- Phase equilibria in the Tl-TlCl-Te system and thermodynamic properties of the compound Tl5Te2Cl
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The Tl-Te-Cl system was studied in the Tl-TlCl-Te composition region by differential thermal analysis, X-ray powder diffraction, and emf and microhardness measurements. A series of polythermal sec- tions, an isothermal section at 400 K, and a projection of the liquidus surface of the phase diagram were con- structed. The ternary compound Tl5Te2Cl characterized by a wide homogeneity region and incongruent melting by a syntectic reaction at 708 K was shown to exist. This compound was found to crystallize in tetragonal lattice (space group I4/mcm) with the parameters a = 8.921 ?, c = 12.692 ?, and Z = 4. Wide phase separation regions were also found in the system, including a three-phase separation region in the Tl-TlCl-Tl2Te sub- system. Regions of primary crystallization of phases, and the types and coordinates of in-and monovariant equilibria in the T-x-y diagram were determined. From emf measurement data, the standard thermody- namic functions of formation and the standard entropy were calculated for the compound Tl5Te2Cl, as follows: =ΔG0 298 355.9 ± 1.1 kJ/mol, =ΔH0298 377.1 ± 5.0 kJ/mol, andΔS0298 = 474.1 ± 6.8 J/(mol K). Pleiades Publishing, Ltd., 2011.
- Babanly,Aliev,Dhafarli,Babanly
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p. 442 - 449
(2011/08/07)
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- Synthesis, characterisation and structures of thio-, seleno- and telluro-ether complexes of indium(III) halides
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The indium(III) halo-bridged octahedral dimers [InX2(L-L)(μ- X)2InX2(L-L)] (X = Cl: L-L = MeS(CH2) 2SMe, MeSe(CH2)2SeMe, nBuSe(CH 2)2Sen/su
- Gurnani, Chitra,Jura, Marek,Levason, William,Ratnani, Raju,Reid, Gillian,Webster, Michael
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p. 1611 - 1619
(2009/05/30)
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- Thermodynamic properties and homogeneity regions of Tl6SCl 4 and Tl5Se2Cl
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In this activity system Tl-Tl2X-X (X = S, Se)are studied using emf measurements of concentration chains relative thallic electrode. The solid phase diagrams of these systems are clarified, homogeneity areas of the compounds Tl6SClsu
- Guseinov,Babanly,Sadygov,Babanly
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p. 129 - 134
(2009/05/30)
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- Synthesis and structure of orthopalladated complexes derived from prochiral iminophosphoranes and phosphorus ylides
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The iminophosphorane Ph2MeP{double bond, long}NPh (1) reacts with Pd(OAc)2 to give the orthopalladated [Pd(μ-Cl){C6H4(PPh(Me){double bond, long}NPh-κ-C,N)-2}]2 (2) as the racemic mixture, which reacts with Tl(acac) to give [Pd(acac){C6H4(PPh(Me){double bond, long}NPh-κ-C,N)-2}] (3). The X-ray structure of (3) has been determined by diffraction methods. The phosphorus ylide Ph2MeP{double bond, long}CHC(O)Ph (5) reacts with Pd(OAc)2 to give the dinuclear [Pd(μ-Cl){C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}]2 (6) as a mixture of isomers. Complex (6) reacts with Tl(acac), PPh3 or AgClO4/dppe giving the mononuclear derivatives [Pd(acac){C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}] (7), [PdCl{C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}PPh3] (8) and [Pd{C6H4(PPh(Me)CHC(O)Ph-κ-C,C)-2}(dppe-P,P′)](ClO4) (9), as mixtures of stereoisomers with high diastereomeric excess.
- Aguilar, David,Aragüés, Miguel Angel,Bielsa, Raquel,Serrano, Elena,Soler, Tatiana,Navarro, Rafael,Urriolabeitia, Esteban P.
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p. 417 - 424
(2008/03/18)
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- Homogeneity ranges of Tl5Te2Cl and Tl 5Te2Br
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This paper systematizes phase-diagram data for the Tl-TlCl(Br)-Te systems and presents their 500-K subsolidus phase diagrams. Tl5Te 2Cl and Tl5Te2Br (Tl5Te3 structure) are shown to be nonstoichiometric compounds with wide homogeneity ranges, which have been accurately determined using emf measurements, x-ray diffraction, and microhardness tests. Using emf data for reversible concentration cells with a thallium electrode, we have evaluated the partial thermodynamic functions of the thallium in the alloys studied, the standard thermodynamic functions of formation of Tl5Te2Cl and Tl5Te2Br, and their standard entropies. The crystal chemistry of these phases of variable composition is discussed in relation to the Tl5Te3 structure.
- Babanly,Chiragov,Yusibov
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p. 1069 - 1075
(2009/02/06)
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- Phase equilibria and thermodynamic properties of the system Tl-TlCl-Se
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Phase equilibria in the system Tl-Se-Cl were studied in the region Tl-TlCl-Se by DTA, X-ray powder diffraction, emf measurements concentration circuits (-) Tl/glycerol + KCl + TlCl/(Tl-Se-Ce) (+), and microhardness measurements. Several vertical sections,
- Babanly,Yusibov,Babanly
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p. 753 - 760
(2008/10/09)
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- Preparative routes to luminescent mixed-ligand rhenium(I) dicarbonyl complexes
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A series of mixed-ligand 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) rhenium(I) dicarbonyl complexes that are emissive in fluid solution has been prepared, which includes a new class of the type cis-[Re(CO)2(P-P)(N-N)]+ (where P-P is a chelating diphosphine and N-N is a chelating polypyridine ligand). The four synthetic routes that have been developed rely on either reactive triflate displacement or abstraction of labile chloro ligands, followed by the use of the strong trans-labilizing effect of P donors or direct use of the trans effect of P donors. The spectroscopic, photophysical, and electrochemical properties of these new complexes systematically vary with the net donor ability of the ligands in the coordination sphere, as shown by correlations with Lever's E L parameters. Lifetimes and quantum yields of the bipyridine complexes encompass a broad range, 25-1147 ns and ca. 0.002-0.11, respectively.
- Smithback, Joanna L.,Helms, Jeffrey B.,Schutte, Erick,Woessner, Stephen M.,Sullivan, B. Patrick
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p. 2163 - 2174
(2008/10/09)
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- Electrophilic activation: Unexpected metal-metal bond-assisted Tl + chelation by a Pt-benzyl moiety instead of chloride abstraction
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The major effect of replacing Ag(I) with Tl(I) salts, which are indiscriminately used as halide abstractors was investigated. It was found that in the absence of donor ligands such as, OTfs-s or acetonitrile, abstraction of the halide from Pt(II) complex or AgBF4 or AgPF 6 in CH2Cl2 resulted in formation of a dynamic cationic complex. The bonding interactions between the d8 Pt(II) and s2 Tl(I) center was assisted by π-donation from the benzyl ligand to the Tl+ ion.
- Oberbeckmann-Winter, Nicola,Braunstein, Pierre,Welter, Richard
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p. 6311 - 6318
(2008/10/09)
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- Diimine-acetylide compounds of ruthenium: The structural and spectroscopic effects of oxidation
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The reaction of Ru(Me2bipy)(PPh3)2CI 2 1 with terminal alkynes HCCR in the presence of TIPF6 leads to the formation of the vinylidene compounds [Ru(Me 2bipy)(PPh3)2CI(
- Adams, Christopher J.,Pope, Simon J. A.
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p. 3492 - 3499
(2008/10/09)
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- Revelation of the nature of the reducing species in titanocene halide-promoted reductions
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The fundamental nature of TiIII complexes generated in tetrahydrofuran by reduction of Cp2TiCl2 has been clarified by means of cyclic voltammetry and kinetic measurements. While the electrochemical reduction of Cp2TiCl2 leads to the formation of Cp2TiCl2-, the use of metals such as Zn, Al, or Mn as reductants affords Cp2TiCl and (Cp 2TiCl)2 in a mixture having a dimerization equilibrium constant of 3 × 103 M-1, independent of the metal used. Thus, we find it unlikely that the trinuclear complexes or ionic clusters known from the solid phase should be present in solution as previously suggested. The standard potentials determined for the redox couples Cp 2TiCl2/Cp2TiCl2-, (Cp2TiCl)2+/(Cp2TiCl)2, Cp2TiCl+/Cp2TiCl, and Cp2Ti 2+/Cp2Ti+ increase in the order listed. However, the reactivity of the different TiIII complexes is assessed as (Cp2TiCl)2 ? Cp2TiCl ≈ Cp 2Ti+ ? Cp2TiCl2- in their reactions with benzyl chloride and benzaldehyde. None of the reactions proceed by an outer-sphere electron transfer pathway, and clearly the inner-sphere character is much higher in the case of Cp2Ti + than for (Cp2TiCl)2, Cp2TiCl, and in particular Cp2TiCl2-. As to the electron acceptor, the inner-sphere character increases, going from benzyl chloride to benzaldehyde, and it is suggested that the chlorine atom in benzyl chloride and the oxygen atom in benzaldehyde may function as bridges between the reactants in the transition state.
- Enemaerke, Rasmus Juel,Larsen, Jens,Skrydstrup, Troels,Daasbjerg, Kim
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p. 7853 - 7864
(2007/10/03)
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- Reactivity of [NBu4][(C6F5) 2M(μ-PPh2)2M′(acac-O,O′)] (M, M′ = Pt, Pd) toward Silver Centers. Synthesis of Polynuclear Complexes Containing M-Ag Bonds (M = Pd, Pt)
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The binuclear complexes [NBu4][(C6F5) 2M(μ-PPh2)2M′(acac-O.O′)] (M = M′ = Pt, la; M = Pt, M′ = Pd, Ib; M = M′ = Pd, 1c) have been prepared by reacting [NBu4]2(C6F 5)2M(μ-PPh2) 2M′(μ-Cl)2M′(μ-PPh2) 2M(C6F5)2] with Tl(acac). Complexes 1a,b react with [Ag(OClO3)-(PPh3)], yielding [MPtAg(μ-PPh2)2(C6F5 2(acac)(PPh3)] (M = Pt, 2a; M = Pd, 2b). The X-ray structures of both complexes are rather similar, the main difference being related with the Pt-Ag bonds. While in 2b it is clear that there are Pt-Ag and Pd-Ag bonds, in 2a it seems that only one Pt-Ag bond is connecting both Pt and AgPPh3 moieties. The formation of a Pd-Ag bond is rather surprising, because of the known reluctance of the Pd center to engage in this sort of bonding. 1a,b react with equimolar amounts of AgClO4 in CH 2Cl2 to give [PtMAg(μ-PPh2) 2(C6F5)2(acac)]x (M = Pt, 4a; M = Pd, 4b). The X-ray structure of 4a indicates that the Pt 2(acac)(C6F5)2(μ-PPh 2) fragments are connected to the silver center through two Pt-Ag bonds (2.875(1), 2.864(1) A) and one Cγ-Ag bond (of the acac ligand). On the other hand, when the homodinuclear palladium derivative reacts with [Ag(OClO3(PPh3)] or AgClO 4, decomposition takes place and [(C6F 5(PPh3Pd(μ-PPh3Pd(acac)] can be detected in the former reaction. These processes are in agreement with the well-known tendency of the pentafluorophenyl-palladate substrates to participate in arylating processes.
- Alonso, Ester,Fornies, Juan,Fortune, Consuelo,Martin, Antonio,Orpen, A. Guy
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p. 5011 - 5019
(2008/10/08)
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- Metal carbene complexes, methods and intermediates for making them and their use in metathesis reactions
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Compounds having one of the general formulae: ???wherein:M is a metal;Z is selected from the group consisting of oxygen, sulphur, NR"" and PR"";R", R"' and R"" are each a radical independently selected from hydrogen, C1-6 alkyl, C3-8 cycloalkyl, aryl and heteroaryl, or R" and R"' together form an aryl or heteroaryl radical, each said radical being optionally substituted;R' is either as defined for R", R"' and R"" when included in a compound having the general formula (IA) or, when included in a compound having the general formula (IB), is selected from hydrogen, C1-6 alkylene and C3-8 cycloalkylene, the said alkylene and cycloalkylene group being optionally substituted;R1 is a constraint steric hindrance group having a pKa of at least about 15;R2 is an anionic ligand;R3 and R4 are each hydrogen or a radical selected from, among others, C1-20 alkyl, C1-20 alkenyl;R3 and R4 together may form a fused aromatic ring system, andy represents the number of sp2 carbon atoms between M and the carbon atom bearing R3 and R4 and is an integer from 0 to 3 inclusive are useful as catalysts for olefin metathesis and atom transfer radical polymerization.
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- Cyclometalated ruthenium chloro and nitrosyl complexes
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The novel cyclometalated RU(III) complex, [Ru(η2-phpy)(trpy)Cl][PF6]·toluene 1, and the {Ru-NO}6 complex, [Ru-(η2-phpy)(trpy)NO][PF6]2 2, where trpy is 2,2′: 6′,2″-terpyridine and phpy is 2-phenylpyridine, have been prepared and characterized by elemental analysis, IR, 1H NMR, and electronic absorption spectroscopies, cyclic voltammetry, and crystallography. The crystal structure of 1 showed the chloride ion trans to the σ-bonding phenyl group of phpy and is an unusual example of a stable paramagnetic cyclometalated complex. The crystal structure of 2 shows the nitrosyl ligand trans to the σ-bonding phenyl group of phpy. The significant distortion of the normally linear Ru-NO bond angle (167.1(4)°) can be largely ascribed to the strong σ-donor properties of the phenyl group.
- Hadadzadeh, Hassan,DeRosa, Maria C.,Yap, Glenn P. A.,Rezvani, Ali R.,Crutchley, Robert J.
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p. 6521 - 6526
(2008/10/08)
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- Synthesis, properties, and ligating behavior of the first facultative tritelluroethers, Te(CH2CH2CH2TeR)2 (R = Me or Ph)
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The first examples of linear tritelluroether ligands, Te(CH2CH2CH2TeR)2 [L, R = Me (L1) or Ph (L2)], have been prepared from Na2Te and RTeCH2CH2CH2Cl and fully characterized spectroscopically and by quanternization with MeI to the corresponding telluronium salts, MeITe(CH2CH2CH2 TeRMeI)2. A series of metal complexes have been prepared, the metal substrate being chosen to illustrate the ligating modes available to these ligands and to permit comparison with literature data on complexes of Se(CH2CH2CH2SeMe)2 and MeC-(CH2TeR)3. In fac-[Mn(CO)3(L)]CF3SO3 the ligands bind as tridentates facially to the metal center, whereas in [PtCl(L)]PF6 the ligands occupy three positions on the square-planar metal center. The [{η5-C5Me5}Rh(L)] (PF6)2 contain tridentate L bound to one triangular face of the octahedron. The X-ray crystal structure of [{η5-C5Me5}Rh(L2)] (PF6)2·MeOH shows tridentate telluroether coordination with the ligand adopting the DL configuration, giving a distorted pseudo-octahedral environment at Rh(III). A short contact between one C-H group in one of the phenyl rings and the centroid of the other phenyl ring (2.56 A?) helps to stabilize the adopted configuration. The metal complexes have been characterized by analysis, ES+ or FAB mass spectrometry, and IR and multinuclear NMR (1H, 13C{1H}, 125Te) spectroscopy. The invertomers present in coordinated L have been established by the multinuclear NMR studies.
- Barton, Andrew J.,Levason, William,Reid, Gillian,Ward, Antony J.
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p. 3644 - 3649
(2008/10/08)
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- Contribution to the chemistry of metal complexes with stereogenic metal centers: Diastereoselective formation of ruthenium half-sandwich complexes
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The chiral half-sandwich complexes 3 and 4 are formed with high diastereoselectivities in the reaction of cyclopentadienides 2a,b, bearing tethered phosphaferrocene donor moieties with planar chirality, and [(PPh3)3RuCl2] in toluene at 90°C. The diastereoisomers of the Cp complex 3 are obtained in a 95:5 ratio, whereas for the Cp* derivative 4 only one isomer is detectable, the structure of which has been determined by X-ray diffraction. Substitution of the chloride ligand in 4 by other anionic (H-, I-) or neutral (H2, py) ligands proceeds stereospecifically in all cases. In contrast, conversion of the chlorides 3a,b (95:5) to the respective hydrides 9a,b proceeds with complete epimerization at Ru. In CHCl3 the 1:1 mixture of hydrides 9a,b is reconverted to the chlorides to give a kinetically controlled 4:1 mixture of isomers 3a,b. Equilibration of this mixture in toluene at 90°C restores the original ratio of isomers of 95:5, which we therefore believe to reflect the thermodynamically controlled value. The cationic H2 complex 7, generated via Cl abstraction from 4 in the presence of H2, was characterized to be a η2-dihydrogen complex by measuring the T1 value of the coordinated H2 ligand.
- Kaulen, Corinna,Pala, Corinne,Hu, Chunhua,Ganter, Christian
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p. 1614 - 1619
(2008/10/08)
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- R4*Tl3Cl and R6*Tl6Cl2 (R* =SitBu3) - The first compounds with larger clusters containing covalently linked thallium atoms
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The largest Tl clusters to date with covalently linked Tl atoms are contained in the title compounds obtained from TlCl3 and two molar equivalents of NaSitBu3 in THF at -78°C. The structure of (SitBu3)6Tl6Cl2, which contains two Tl3Cl four-membered rings linked through the central Tl atoms and the Cl atoms, is depicted.
- Wiberg, Nils,Blank, Thomas,Lerner, Hans-Wolfram,Fenske, Dieter,Linti, Gerald
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p. 1232 - 1235
(2007/10/03)
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- Hydrogenation of quinoline by rhodium catalysts modified with the tripodal polyphosphine ligand MeC(CH2PPH2)3
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As part of our modelling studies of the hydrodenitrogenation of N-heterocycles contained in raw oil materials, we investigated the selective hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline by rhodium catalysts modified with the tripodal polyphos
- Bianchini, Claudio,Barbaro, Pierluigi,Macchi, Michela,Meli, Andrea,Vizza, Francesco
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p. 2895 - 2923
(2007/10/03)
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- Electrophilic additions of metal fragments containing 11- and 12-group elements to the anion carbide cluster [Fe5MoC(CO)17]2-. X-ray crystal structures of (NEt4)[Fe5MoAuC(CO)17(PMe3)] and [Fe5MoAu2C(CO)17(dppm)]
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The reaction of (NEt4)2[Fe5MoC(CO)17] with cationic metal fragments gives a series of clusters whose most striking structural feature is the selective addition of the incoming metal units on the triangular Fe2Mo face of the starting anion. The use of Au2(dppm)2+ (dppm = diphenylphosphinomethane) gives the cluster [Fe5MoAu2C(CO)17(dppm)] in which the di-gold fragment adopts an unprecedented bonding mode.
- Reina, Roser,Rodríguez, Laura,Rossell, Oriol,Seco, Miquel,Font-Bardia, Mercè,Solans, Xavier
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p. 1575 - 1579
(2008/10/08)
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- Mononuclear (Pd, Pt), heterodinuclear (PdAg, PtAg), and tetranuclear (Pd2Ag2, Pt2Ag2) 1,1-ethylenedithiolato complexes
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1p;&-5q; 1 The reactions of [Tl2{S2C=C{C(O)Me}2}]n with [MCl2L2] (1:1) or with [MCl2(NCPh)2] and PPh3 (1:1:2) give complexes [M{η2-S2C
- Vicente,Chicote,Huertas,Bautista,Jones,Fischer
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p. 2051 - 2057
(2008/10/08)
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- Synthesis and characterisation of the first carbene-thallium complexes: Molecular structure of[TlCl3{CN(Mes)C2H2N(Mes)}], Mes = C6H2Me3-2,4,6
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The reaction of the stable carbenes,:CN(Mes)C2R2N(Mes), R = H (IMes) or Br (IMesBr), with TlX3, X = Cl or Br, Mes = mesityl, yields the complexes, [TlX3{CN(Mes)- C2R2N(Mes)}], one of which,
- Cole,Davies,Jones
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p. 2451 - 2452
(2007/10/03)
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- A donor - Acceptor - Donor bridging ligand in a class III mixed-valence complex
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The novel mononuclear and dinuclear complexes [Ru(trpy)(bpy)(apc)][PF6] and [{Ru(trpy)(bpy)}2(μ -adpc)][PF6]2 (bpy = 2,2′-bipyridine, trpy = 2,2′:6′,2″-terpyridine, apc- = 4-azo(phenylcyanamido)benzene, and adpc2- = 4,4′ -azodi(phenylcyanamido)) were synthesized and characterized by 1H NMR, UV-vis, and cyclic voltammetry. Crystallography showed that the dinuclear Ru(II) complex crystallizes from diethyl ether/acetonitrile solution as [{Ru(trpy)(bpy)}2gt-adpc)][PF6] 2·2(acetonitrile)·2(diethyl ether). Crystal structure data are as follows: crystal system triclinic, space group P1, with a, b, and c = 12.480(2), 13.090(3) and 14.147(3) A, respectively, α, β, and γ = 79.792(3), 68.027(3), and 64.447(3)°, respectively, V = 1933.3(6) A, and Z = 1. The structure was refined to a final R factor of 0.0421. The mixed-valence complex with metal ions, separated by a through-space distance of 19.5 A, is a class III system, having the comproportionation constant Kc. = 1.3 × 1013 and an intervalence band at 1920 nm (εmax = 10 000 M-1 cm-1), in dimethylformamide solution. The results of this study strongly suggest that the bridging ligand adpc2- can mediate metal-metal coupling through both hole-transfer and electron-transfer superexchange mechanisms.
- Mosher,Yap,Crutchley
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p. 1189 - 1195
(2008/10/08)
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- Organoantimony(V) cyanoximates: Synthesis, spectra and crystal structures
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A series of 25 new organoantimony(V) cyanoximates has been synthesized and studied using IR, visible, and NMR spectroscopy and X-ray analysis. Crystal structures were determined for compounds (C6H5)4Sb{ONC(CN)C(O)NH2} (1) and (C6H5)4Sb{ONC(CN)C(O)N(CH3)2} (2). Both complexes crystallized in the monoclinic space group P21/c (Z = 4) with unit cell parameters (A, grad) of a = 14.921(3), b = 10.165(2), c = 17.571(7), β = 113.26(6) for compound 1, and a = 16.415(4), b = 10.406(3), c = 17.152(3), β = 117.79(2) for compound 2. For 5438 and 5056 independent reflections the refinement yielded R-factors 0.022 and 0.037 for the structures of 1 and 2, respectively. Cyanoxime anions are bound to the antimony(V) atoms in a monodentate fashion via the oxygen atoms of the oxime groups. The ligands adopt trans-anti configuration in these compounds. The coordination polyhedron in both complexes is a distorted trigonal bipyramid with the axial location of the cyanoxime ligand. A similar binding mode of other anions in synthesized organoantimony(V) complexes has been offered on the basis of the similarity of their IR spectra to those of the compounds whose structures were determined crystallographically. The exact assignment of vibrations involving the oxime group was carried out using synthesized 15N (53%) isotopomers.
- Domasevitch, Konstantin V.,Gerasimchuk, Nikolay N.,Mokhir, Andrew
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p. 1227 - 1237
(2008/10/08)
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- Express Method for Production of Radiopharmaceutical Based on Thallium-199 Chloride
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An express method was developed for production of a radiopharmaceutical(RP) for intravenous injection based on thallium-199 chloride. The procedure involved distillation of thallium in the form of chloride in a hermetically sealed quartz installation in a flow of hydrogen chloride, followed by condensation of the nuclides in traps filled with water. After adding NaCl to obtain physiological solution and removing HCl by evaporation, the residue is dissolved in water and sterilized. The total duration of the procedure is about 2 h.
- Kordyukevich, V. O.,Kuznetsov, V. I.,Giruts, V. L.,Yuminov, O. A.,Fotina, O. V.,et al.
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p. 181 - 183
(2008/10/08)
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