38117-54-3Relevant articles and documents
Synthesis of heteronuclear di- and tri-metal μ-carbyne compounds from the thiocarbyne (CO)2WCSMe
Doyle, Ruth Ann,Angelici, Robert J.,Gordon F.,Stone, A.
, p. 81 - 90 (1989)
The compound (CO)2WC-SMe (1) reacts with two equivalents of (In)Rh(CO)2, where In = η5-indenyl, C9H7, in refluxing THF to give the brown-black crystalline μ3-carbyne > (2) containing a Rh2W triang
Synthesis and characterization of a polycarbon organometallic cluster, [PPN]2[Fe6(CO)18C4]
Norton,Shriver
, p. 5118 - 5120 (2000)
The polycarbon metal cluster [Fe6(CO)18C4]2- is formed by the reaction of CF3SO3SO2CF3 with [Fe3(CO)9(CCO)]2-. Apparently, the SO2CF3 moiety abstracts an oxygen from the ketenylidene (CCO) ligand and C - C coupling occurs to form the C4 ligand. A single-crystal X-ray structure determination reveals that the pattern of C-C bond lengths of the C4 ligand in [Fe6(CO)18C4]2- mimic those in free butadiene.
One-electron reduction of molybdenum η2(4e)-alkyne complexes as a pathway to the η2(3e) vinyl ligand
Baines, Sarah,Cowley, Michael J.,Chafen, Andrew R.,Lynam, Jason M.,Spinks, Deborah C.,Whitwood, Adrian C.
, p. 1093 - 1095 (2007)
Reaction of the molybdenum alkyne complex [Mo-(P{OMe}3) 2(η2{4e}-PhC2Ph)(η5-C 5H5)][BF4] with K[Fe(CO)2- (η5-C5H5)] results in the formation of the η2(3e)-vinyl complex [Mo(P{OMe}3)2(η 2{3e}=CPh-CHPh)(η5-C5H5)] and [Fe-(CO)2(η5-C5H5)] 2. A study of the reaction by EPR spectroscopy implies that the reaction proceeds via [Mo(P{OMe}3)2(η2{4e}- PhC2Ph)(η5-C5H5)], which is then thought to undergo a hydrogen-abstraction reaction to give the observed product. The same radical was observed in the reaction of [Mo(P{OMe} 3)2-(η2{4e}-PhC2Ph) (η5-C5H5)][BF4] with LiBEt 3H, implying the presence of an alternative mechanistic pathway to the direct addition of hydride to the molybdenum alkyne complex.
Preparation and Chiroptical Properties of Optically Active Vinyl Ether-Iron and Olefin-Iron Complexes. A CD Quadrant Rule Correlating Absolute Configurations.
Begum, M. Kohinoor,Chu, Kai-Hsuan,Coolbaugh, Thomas S.,Rosenblum, Myron,Zhu, Xiao-Ya
, p. 5252 - 5259 (1989)
Exchange etherification of dicarbonylcyclopentadienyl(η2-ethyl vinyl ether)iron tetrafluoroborate (4) with optically active primary and secondary alcohols yields a mixture of diastereomeric cations.These isomers are in rapid equilibrium at room
MEHRFACHBINDUNGEN ZWISCHEN HAURTGRUPPENELEMENTEN UND UEBERGANGSMETALLEN. XXXII. INSERTIONS- UND METATHESEREAKTIONEN VON METALLORGANISCHEN EISEN-SELEN-KOMPLEXEN
Herrmann, Wolfgang A.,Rohrmann, Juergen,Herdtweck, Eberhardt,Hecht, Christian,Ziegler, Manfred L.,Serhadli, Orhan
, p. 295 - 306 (1986)
The compound (μ-Se)(η5-CpercentH5)Fe(CO)2>2 (1) has labile metal-selenium bonds and therefore undergoes insertion and metathesis reactions.Thus, reaction with elemental selenium gives the novel FeSeSeFe chain-type complex (μ,η1:η1-Se2)5-CpercentHpercent)Fe(CO)2>2 (2).Both compounds 1 and 2 react with the homodinuclear chromium complex 5-C5H5)Cr(CO)3>2 with formation of the heterodinuclear derivatives of composition (η5-C5H5)2CrFe(CO)5 (3; single-crystal X-ray structure: d(Cr-Fe) 290.1(1) pm) and (μ-Se2)5-C5H5)2CrFe(CO)4> (4).The latter compound exhibits a diselenido bridge ligand in η1:η2-coordination (single-crystal X-ray structure: d(Cr-Se) 249.5(2) and 255.5(2) pm, d(Fe-Se) 238.9(2), d(Se-Se) 229.7(1) pm) and can also be obtained by treatment of the chromium complex 3 with elemental selenium.
Spectroscopic Evidence for the Formation of Tri-μ-carbonyl-bis-5-cyclopentadienyl)iron> on Photolysis of Bis5-cyclopentadienyl)iron> in Low Temperature Matrices
Hooker, Richard H.,Mahmoud, Khalil A.,Rest, Antony J.
, p. 1022 - 1024 (1983)
Photolysis of 5-C5H5)Fe(CO)2>2> in CH4 (12 K) and polyvinyl chloride film (12-77 K) matrices leads to the formation of a novel species proposed, on the basis of i.r. evidence including 13CO enrichment and u.v.-visible spectra, to be the CO-bridged dimer 5-C5H5)Fe>2>.
Chemical and structural effects of bulkness on bent-phosphinidene bridges: Synthesis and reactivity of the diiron complex [Fe2Cp 2{μ-P(2,4,6-C6H2tBu 3)}(μ-CO)(CO)2]
Alvarez, M. Angeles,Garcia, M. Esther,Gonzalez, Rocio,Ramos, Alberto,Ruiz, Miguel A.
, p. 1875 - 1878 (2010)
The steric pressure introduced by the 2,4,6-C6H2 tBu3 group (R*) in the complex [Fe 2Cp2(μ-PR*)(μ-CO)(CO)2] (Cp = η5-C5H5) has pronounced effects
Diiron aminoalkylidene complexes
Zanotti, Valerio,Bordoni, Silvia,Busetto, Luigi,Carlucci, Lucia,Palazzi, Antonio,Serra, Rossella,Albano, Vincenzo G.,Monari, Magda,Prestopino, Fabio,Laschi, Franco,Zanello, Piero
, p. 5232 - 5241 (1995)
The reactions of the sulfonium salts [Fe2(CO)2(cp)2(μ-CO){μ-C(X)SMe 2}]SO3CF3 [X = CN (1a), H (1b)] with a variety of amines are presented. 1a yields ammonium cations [Fe2-(CO)2(cp)2(μM-CO){μ-C(CN)NR 3}] [R = Me (2), Dabco (3) (Dabco = 1,4-diazabicyclo[2.2.2]-octane)], aminoalkylidene [Fe2(CO)2(cp)2(μ-CO){μ-C(CN)NR 2}] (4), isocyanide [Fe2(CO)2(cp)2(μ-CO)(μ-CNR)] (7), or diaminoalkylidene [Fe2{CN(H)(CH2)2N(H)}(CO)(cp) 2(μ-CO)2] (11) complexes by reacting with tertiary amines, secondary amines, primary amines, or ethylenediamine, respectively. 1b and secondary amines yield [Fe2(CO){C(H)NR2}(cp)2(μ-CO)2] (6). The formation of type 4 bridging and 6 terminal aminoalkylidene derivatives also via μ-C addition of CN- or H- to aminoalkylidyne [Fe2(CO)2(cp)2(μ-CO)(μ-CNR 2)]+, respectively, as well as the preparation of the terminal [Fe2{C(CN)NPri2}(CO)(cp) 2(μ-CO)2] (5) from 1a and NHPri2, allows to clarify the role of electronic and steric effects in determining the position of the aminoalkylidene ligands. The X-ray structure of 5 has been determined. The crystal contains two independent molecules of the trans-isomer. The terminally bonded aminoalkylidene ligand exhibits weaker Fe-C(carbene) (Fe-C 1.915(3) A?) and stronger C(carbene)-N(amine) π bonds (C-N 1.320(4) A?) with respect to the bridging coordination. Electrochemistry shows that 5 undergoes a chemically reversible one electron oxidation to the corresponding monocation [5]+, which has been characterized by X-band EPR spectroscopy. All the complexes have been spectroscopically characterized, and a variable-temperature NMR on [Fe2(CO){C(H)NMe2}(cp)2(μ-CO)2] (6a) indicates exchange of the aminoalkylidene ligand between the two Fe atoms.
IRON-SILICON BOND CLEAVAGE IN DICARBONYL(η5-CYCLOPENTADIENYL)(TRIMETHYLSILYL)IRON USING TETRABUTYLAMMONIUM FLUORIDE
Marten, David F.,Wilburn, Susan M.
, p. 71 - 78 (1983)
Dicarbonyl(η5-cyclopentadienyl)(trimethylsilyl)iron (1) was found to react with a 1 M solution of tetrabutylammonium fluoride (2) in tetrahydrofuran at 25 deg C to give dicarbonyl(η5-cyclopentadienyl)iron anion (5).The anion generated under these conditions was trapped with electrophiles (R-X) to give 45-89percent yields of neutral dicarbonyl(η5-cyclopentadienyl)-alkyl, -allyl, -acyl-iron compounds and the ethylene cation.Tetrabutylammonium hydroxide also can be used in this reaction.Evidence indicates that fluoride ion instead of hydroxide attacks the silicon when tetrabutylammonium fluoride is used since fluorotrimethylsilane can be detected in the reaction product.Tetrabutylammonium fluoride and hydroxide quantitatively liberate styrene from dicarbonyl(η5-cyclopentadienyl)(η2-styrene)iron tetrafluoroborate, producing bis2-cyclopentadienyl)iron>.
Silver(I) Salts as One-electron or Two-electron Oxidants in their Reactions with 2(η-C5H5)2(CO)4-n(CNMe)n> Derivatives (n = 0-2). The Effect of Varying the Reaction Solvent
Callan, Brian,Manning, A. R.
, p. 263 - 264 (1983)
In tetrahydrofuran AgNO3 acts as a two-electron oxidant and cleaves to give a mixture of and via a detectable adduct, but in acetonitrile it acts as a one-electron oxidant to give NO3 and the . radical which then dimerises or reacts with added radical traps.
Thermolysis reactions of iron and ruthenium metallocarboxylic acids
Gibson, Dorothy H.,Ong, Tek-Sing
, p. 1911 - 1913 (1984)
A new synthesis of CpFe(CO)(PPh3)COOH is described as is the preparation of a new metallocarboxylic acid, CpRu(CO)(PPh3)COOH. Upon heating, the iron acid provided Cp2Fe2(CO)3(PPh3), as the first isolable product, which resulted from reaction of the acid with its decarboxylation product CpFe(CO)(PPh3)H. The ruthenium acid decarboxylated to the hydride in acetone, but it was stable to thermolysis in benzene. The ruthenium acid is not reactive toward CpM(CO)(PPh3)H (M = Fe, Ru). Thermolyses in chlorinated solvents take place wholly (iron acid) or in part (ruthenium acid) by redox paths; both acids were also readily oxidized by Ag+.
LXXVIII. Der optisch aktive Phosphido-verbrueckte Eisenkomplex 5-C5H5)2Fe2(μ-H)(μ-PMen2)(CO)2> - Synthese, Isomerisierung, Katalysen
Brunner, Henri,Roetzer, Michael
, p. 119 - 124 (1992)
The hydrido-phosphido-bridged complex 5-C5H5)2Fe2(μ-H)(μ-PMen2)(CO)2> (3) is prepared from 5-C5H5)Fe(CO)2>2 (1) and dimenthylphosphine HPMen2 in boiling toluene.The reaction proceeds via the intermediate 5-C5H5)2Fe2(HPMen2)(CO)3> (2). 2 forms a pair of cis-trans isomers, whereas 3 consists of three isomers, the meso-isomer cis-3 and the two diastereomers trans-3a and trans-3b.In hot toluene, 2 gives 1 and 3.In solution 3 undergoes a photochemical cis-trans isomerization reaction. 3 is an enantioselective catalyst in the photochemical hydrosilylation of acetophenone with diphenylsilane to give 1-phenylethanol in up to 33percent ee.
Synthesis and characterization of triplet germylene-bridged diiron complexes and singlet stannylene-bridged diiron complexes
Mohamed, Bahaa A. S.,Kikuchi, Mami,Hashimoto, Hisako,Ueno, Keiji,Tobita, Hiromi,Ogino, Hiroshi
, p. 112 - 113 (2004)
Photoreaction of CpFe(CO)2Me with sterically congested R 2GeH2 [R = 2,4,6-C6H2 iPr3 (Tip), 2,4,6-C6H2Me3 (Mes)] afforded paramagnetic germylene-bridged diiron complexes having a triplet ground state, Cp2Fe2(μ-CO)2(μ,- GeR2) (3a, R = Tip; 3b, R = Mes), while the analogous reaction with R2SnH2 afforded diamagnetic complexes Cp 2Fe2(CO)2(μ-CO)(μ-SnR2) (trans-5a, R = Tip; trans-5b, R = Mes). The structure of 3a was determined by X-ray crystallography.
Manning, A. R.,McNally, Gerard,Soye, Paul
, p. 103 - 110 (1991)
UEBERGANGSMETALL-SILYL-KOMPLEXE V. HETEROZWEIKERN-KOMPLEXE MIT DEM MeCp(CO)2(R3Si)Mn-FRAGMENT
Schubert, Ulrich,Kunz, Erika
, p. C1 - C4 (1986)
The reactivity of the anionic silyl complex Na (1) towards a number of transition metal halide complexes has been investigated.Reaction with Cp(CO)2FeI yields cis- and trans-MeCp(CO)(MePh2Si)Mn(μ-CO)2Fe(CO)Cp (2).With Ph3PAuCl or PhHgBr the very stable heterodinuclear complexes MeCp(CO)2(MePh2Si)MnAuPPh3 (3) or MeCp(CO)2(MePh2Si)MnHgPh (4) are obtained.
Reactions of > with (M=Ru or Os) in the Presence of Hydrogen. Synthesis and Crystal Structure of the New Heterotetrametallic Complex > and Spectroscopic Characterization of a Planar Isomer
Marchino, Maria Luisa Nanni,Sappa, Enrico,Lanfredi, Anna Maria Manotti,Tiripicchio, Antonio
, p. 1541 - 1546 (1984)
The influence of molecular hydrogen on the title reactions has been studied; different products (and yields) are obtained when this gas is used, instead of nitrogen, as reaction atmosphere.From the reactions of with > the new heterometallic complex > is obtained, whose structure has been determined by X-ray methods.Crystals are triclinic, space group P1, with a unit cell of dimensions a = 8.881(7), b = 17.224(12), c = 7.912(7) Angstroem, α =78.87(4), β = 114.95(6), γ = 91.60(4) degree, and Z = 2.The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least squares to R = 0.046 for 2 965 observed reflections.The complex shows a 'spiked-triangular' metal atom frame and the alkyne ligand interacts with all four metals through both triple and double bonds.An isomeric complex has been also characterized and a square-planar structure has been assigned to it on the basis of spectroscopy and by comparison with known compounds.From the reactions of with the same alkyne, instead of the expected >, the already known > complex has been obtained, by consequence of the hydrogenation of the reactant double bond.
Reactions of carbon disulfide and carbon dioxide adducts (η-C5H5(CO)2FeCX-2 with organoiron electrophiles
Giuseppetti-Dery, Mary E.,Landrum, Bruce E.,Shibley, John L.,Cutler, Alan R.
, p. 421 - 436 (1989)
Reactions of FpCS-2K+ (1) and FpCO2-Na+ (and Li+) (2) (Fp=(η5-C5H5)(CO)2Fe) with organoiron electrophiles FpX (X=I, OSO2CF3, HgCl), (η5-C5H5)L(CO)FeI (L=P(OPh3), PPh3)
cis-Stereochemistry on Nucleophilic Addition to a Cationic η2-Alkyne Complex, 5-C5H5)Fe(CO)2(Ph-CC-Ph)>BF4
Akita, Munetaka,Kakuta, Satoshi,Sugimoto, Shuichiro,Terada, Masako,Moro-oka, Yoshihiko
, p. 451 - 453 (1992)
Treatment of a coordinatively saturated cationic η2-alkyne iron complex 5-C5H5)Fe(CO)2(Ph-CC-Ph)>BF4 with various nucleophiles (Nu: O-, S- and N-nucleophiles) does not afford a trans-alkenyl complex but alkenic products with cis-structure, i.e. a cis-alkenyl complex, cis-(η5-C5H5)(CO)2Fe-C(Ph)=C(Ph)-Nu and/or a metallacycle, (η5-C5H5)(OC))-Nu> or (η5-C5H5)(OC)>.
Synthesis of the cationic silyleneiron complex [(η-C5H5)Fe(CO)2=SiMe{2-(Me 2NCH2)C6H4}]PF6 by hydride abstraction from a (hydrosilyl)iron complex with Ph3CPF6
Kobayashi, Hideki,Ueno, Keiji,Ogino, Hiroshi
, p. 5490 - 5492 (1995)
A cationic intramolecular base-stabilized silyleneiron complex, [(η-C5H5)Fe(CO)2=SiMe{2-(Me 2-NCH2)C6H4}]PF6, was synthesized by hydride abstraction from the (hydrosilyl)iron complex (η-C5H5)Fe-(CO)2SiHMe{2-(Me 2NCH2)C6H4} with Ph3CPF6. Reaction of the silylene complex with MeOH afforded the methoxysilyl complex [(η-C5H5)Fe(CO)2SiMeOMe{2-(Me 2N(H)CH2)C6H4}]PF6 in good yield. The molecular structures of the silylene and methoxysilyl complexes were determined by X-ray crystal structure analysis.
Functionalization of Cp4Fe4(CO)4 with Alkyl, Aryl, and Ferrocenyl Groups and the Preparation of Double Clusters [Cp3Fe4(CO)4(C5H4)] 2 and [Cp3Fe4(CO)4(C5H4)] 2[(C5H4)2Fe]
Yeh, Wen-Yann,Wu, Ching-Yuan,Chiou, Leu-Wen
, p. 3547 - 3550 (1999)
Reaction of Cp4Fe4(CO)4 (1) with RLi and HBF4 in sequence affords Cp3Fe4(CO)4(C5H4R) (R= Me, Bun, and Ph) in moderate yields. Further sequential PhLi/HBF4 treatment of Cp3Fe4(CO)4(C5H4Ph) produces Cp2Fe4(CO)4(C5H4Ph) 2. On the other hand, 1 reacts with lithium diisopropylamide (LDA) and bromoferrocene sequentially to produce a ferrocenylated cluster [Cp3Fe4(CO)4(C5H 4)][(C5H4)FeCp] (3) and a double cluster [Cp3Fe4(CO)4(C5H4)] 2 (2). A similar LDA/dibromoferrocene treatment with 1 leads to 2, [Cp3Fe4(CO)4(C5H 4)][(C5H4)(C5H4Br)Fe] (4), and a ferrocenyl-bridged double cluster [Cp3Fe4(CO)4(C5H4)] 2[(C5H4)2Fe] (5). The new compounds have been characterized by elemental analysis and IR, mass, and NMR spectroscopy.
INSERTION REACTIONS OF t-Bu(η5-C5H5)Fe(CO)2
Pannell, Keith H.,Giasolli, Tony,Kapoor, Ramesh N.
, p. 315 - 318 (1986)
The complex t-Bu(η5-C5H5)Fe(CO)2 has been treated with triphenylphosphine in refluxing THF to produce t-BuCO(η5-C5H5)Fe(CO)(PPh3).The large steric bulk of the t-butyl group suggests that this reaction should be faster than the reaction involving the methyl group, and a kinetic investigation illustrates this to be the case.The same steric bulk predicts that the reaction with SO2 should be slow, and indeed we have been unable to effect the related SO2 insertion reaction.Attempts to prepare the corresponding t-Bu(η5-C5H5)W(CO)3 led to formation of the related isobutyl complex.
ATOM-TRANSFER REDOX REACTIONS OF NITRITE ANION WITH TRANSITION METAL CARBONYL CATIONS
Lalor, Fergus J.,Brookes, Leslie H.
, p. 327 - 332 (1983)
The reactions of several carbonyl cations with bis(triphenylphosphine)imminium nitrite under aprotic conditions have been studied using acetone as solvent.The trigonal-bipyramidal iron(0) and colbalt(I) cations +, +, + and + yielded four-coordinate iron(-II) and cobalt(-I) nitrosyl complexes Fe(NO)(N2C6H4COCH3-p)(CO)(PPh3), Fe(NO)2(CO)(PPh3), Fe(NO)2(PPh3)2, Co(NO)(CO)2(PPh3) and Co(NO)(CO)2(P(Bu-n)3) via a procedure which is much simpler than previous methods.The reaction involves an atom-transfer redox between nitrite and coordinated CO to yield the coordinated nitrosyl ligand and CO2.The related cation + did not react.The other cations investigated underwent decomposition and/or gave non-nitrosyl products with the exception of + which yielded an unstable blue nitrosyl which could not be characterised.A modification of the procedure employing Na(15)NO2 in the presence of a catalytic amount of crown ether was shown to be a very simple method for the preparation of 15N-labelled nitrosyls.The analogues reaction with arenediazotate anion did not lead to arenediazo complexes.
Methyl abstraction kinetics of CpFe(CO)2Me using the benzyl radical clock
Chong, Thiam Seong,Chwee, Tsz Sian,Leong, Weng Kee,Wong, Ming Wah,Fan, Wai Yip
, p. 687 - 692 (2006)
The rate constant for the methyl abstraction reaction of CpFe(CO) 2Me has been measured with the benzyl radical clock as (1.1 ± 0.2) × 105 M-1 s-1 at room temperature. Time-resolved Fourier-transform Infrared (FTIR) absorption spectroscopy pointed towards the formation of the CpFe(CO)2 radical upon benzyl abstraction. The main stable product has been established by a linear scan of the reaction mixture as Cp2Fe2(CO)4 produced by the dimerization of the CpFe(CO)2 radicals. The transition state structure for the abstraction process was also found at UB3LYP/6-311+G* level of theory to contain a planar CH3 group.
Photochemistry of (η5-C5H5)(η5-C4H4N)Fe and (η5-C5H5)(η1-N-C4H4N)Fe(CO)2 in low-temperature matrixes and room-temperature solution. Evidence for a photoinduced haptotropic shift of the π-coordinated pyrrolyl ligand
Heenan, Davnat P.,Long, Conor,Montiel-Palma, Virginia,Perutz, Robin N.,Pryce, Mary T.
, p. 3867 - 3873 (2000)
Azaferrocene, (η5-C5H5)(η5-C4H4N)Fe, undergoes a η5→η1 haptotropic shift of the pyrrolyl ligand upon long-wavelength photolysis (λexc>495 nm) both in alkane solvents at room temperature and in frozen matrixes at 12 K. Room-temperature photolysis (λexc>495 nm) in CO-saturated cyclohexane solution generated (η5-C5H5) (η1-N-C4H4N)Fe(CO)2. Irradiation with λexc = 532 nm also produced an allyl monocarbonyl species, exo-(η5-C5H5)(η3-C-C4H4N)Fe(CO), identified by IR spectroscopy. In CO-doped matrixes at 12 K both (η5-C5H5)(η1-N-C4H4N)Fe(CO) and (η5-C5H5)(η1-N-C4H4N)Fe(CO)2 are formed following broad-band irradiation (λexc>495 nm) of (η5-C5H5)(η5-C4H4N)Fe, in a ratio dependent on the concentration of CO in the matrix. Initial irradiation with λexc = 538 nm followed by broad-band photolysis (λexc>495 nm) in CO-doped matrixes formed additional monocarbonyl species, exo-(η5-C5H5) (η3-C-C4H4N)Fe(CO), and a species absorbing at 1962 cm-1, which is either the appropriate endo-isomer or aza-allyl species. Laser flash photolysis experiments of (η5-C5H5)(η1-N-C4H4N)Fe(CO)2 in either CO-saturated cyclohexane or toluene produced (η5-C5H5)(η1-N-C4H4N)Fe(CO), which reacted with CO with rate constants measured at 298 K of (3.0±0.3)×108 and (3.3±0.3)×108 M-1 s-1, respectively, regenerating (η5-C5H5)(η1-N-C4H4N)Fe(CO)2.
Open Fp chemistry: Synthesis, structure, and chemistry of (2,4-dimethylpentadienyl)iron dicarbonyl iodide
Ma, Huairang,Weber, Paul,Ziegler, Manfred L.,Ernst, Richard D.
, p. 854 - 860 (1987)
The syntheses and properties of 2,4-dimethylpentadienyl (2,4-C7H11) analogues of (C5H5)Fe(CO)2X (Fp) complexes have been investigated. Thus, reaction of (2,4-C7H11)Fe(CO)3+ with KI in acetone leads to Fe(2,4-C7H11)(CO)2I, for which NMR spectroscopy indicates an unsymmetric structure (ΔG? = 11.45 kcal/mol). Reduction with sodium amalgam leads to the dimer [(2,4-C7H11)Fe(CO)2]2, for which an ESR signal can be observed in solution. An unsymmetric dimer, [(C5H5)Fe(CO)2][(2,4-C7H 11)Fe(CO)2], can be prepared from the iodide on reaction with (C5H5)Fe(CO)2-. Treatment of the iodide complex with an excess of sodium amalgam leads to the apparent formation of (2,4-C7H11)Fe(CO)2-, which can be converted to the thermally unstable liquid (2,4-C7H11)Fe(CO)2(CH3) with CH3I. Like the analogous iodide complex, this species also exists in an unsymmetric configuration, as indicated by NMR spectroscopy (ΔG? = 12.75 kcal/mol). The methyl compound reacts with P(CH3)2(C6H5) to yield a solid η1-acyl complex, which is itself thermally converted to at least two other products, which appear to involve acyl-pentadienyl coupling. A single-crystal X-ray diffraction study on (2,4-C7H11)Fe(CO)2I has confirmed the unsymmetric coordination environment, in which the iodide and one carbonyl ligand reside under the C(2) and C(4) positions, with the second carbonyl under the open edge of the pentadienyl ligand. The average Fe-CO and Fe-I bond distances are 1.780 (5) and 2.645 (1) A?, while the Fe-C(pentadienyl) bond distances range from 2.100 (6) to 2.158 (8) A?, averaging 2.133 A?. The space group is C2h5 - P21/n (No. 14), with a = 8.034 (2) A?, b = 16.589 (4) A?, c = 8.485 (2) A?, β = 91.24 (2)°, and V = 1130.7 (4) A?3, for Z = 4 and Dcalcd = 1.96 g/cm3. The final agreement indices are R = 0.037 and Rw = 0.031 for the 1595 independent observed reflections.
Heterobimetallic complexes of rhodium dibenzotetramethylaza[14]annulene [(tmtaa)RH-M]: Formation, structures, and bond dissociation energetics
Imler, Gregory H.,Peters, Garvin M.,Zdilla, Michael J.,Wayland, Bradford B.
supporting information, p. 273 - 279 (2015/03/13)
A rhodium(II) dibenzotetramethylaza[14]annulene dimer ([(tmtaa)Rh]2) undergoes metathesis reactions with [CpCr(CO)3]2, [CpMo(CO)3]2, [CpFe(CO)2]2, [Co(CO)4]2, and [Mn(CO)5]2 to form (tmtaa)Rh-M complexes (M = CrCp(CO)3, MoCp(CO)3, FeCp(CO)2, Co(CO)4, or Mn(CO)5). Molecular structures were determined for (tmtaa)Rh-FeCp(CO)2, (tmtaa)Rh-Co(μ-CO)(CO)3, and (tmtaa)Rh-Mn(CO)5 by X-ray diffraction. Equilibrium constants measured for the metathesis reactions permit the estimation of several (tmtaa)Rh-M bond dissociation enthalpies (Rh-Cr = 19 kcal mol-1, Rh-Mo = 25 kcal mol-1, and Rh-Fe = 27 kcal mol-1). Reactivities of the bimetallic complexes with synthesis gas to form (tmtaa)Rh-C(O)H and M-H are surveyed.
Synthesis of diiron μ-allenyl complexes by electrophilic addition to propen-2-yl-dimetallacyclopentenone species: A joint experimental and DFT study
Agonigi, Gabriele,Bortoluzzi, Marco,Funaioli, Tiziana,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
, p. 61 - 66 (2013/05/21)
The propen-2-yl-dimetallacyclopentenone complex [Fe2Cp 2(CO)(μ-CO){μ-η1:η3-C α(H)Cβ(Cγ(CH 3)CH2)C(O)}] (1) underwent electrophilic additions at the propenyl moiety to afford the μ-allenyl complexes [Fe2Cp 2(CO)2(μ-CO){μ-η1: η2α,β-CαHC βCγ(CH3)(CH2E)}][BF 4] (E = CPh3, [2][BF4]; E = H, [3][BF 4]), in ca. 85% yield. The molecular structure of ([2][BF 4]) was ascertained by X-ray diffractometry; X-ray, NMR and DFT results agreed in that one single isomer formed, bearing the [CH 2CPh3] group pointing far from the Fe-Fe axis. The reaction of [3][BF4] with NHEt2 in the presence of PhSSPh resulted in the prevalent formation of [FeCp(CO)2SPh] (7).
