- ORGANOMETALLOIDAL DERIVATIVES OF THE TRANSITION METALS X. PHOTOCHEMICAL THERMAL AND SO2 INDUCED 1,2-PHENYL AND 1,2-SULPHINATOPHENYL MIGRATIONS FROM LEAD TO TRANSITION METALS IN THE SYSTEM 5-C5H5)M(CO)nPbPh3> (M = Fe, Cr, Mo, W)
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The complexes 5-C5H5)M(CO)nPbPh3> (M = Fe, Cr, Mo, W) have been studied with respect to their thermal and photochemical stability and their reactivity with respect to SO2.The iron complex is the only complex that exhibits the ability to decompose via a 1,2-phenyl migration to the transition metal under thermal conditions, but photochemically the tungsten complex also exhibits this behaviour.All complexes react readily with SO2 to yield the correponding sulphinatophenyl complexes, LM-SO2-Ph, in high yield.
- Pannell, Keith H.,Kapoor, Ramesh N.
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- Synthesis and characterization of lead (IV) precursors and their conversion to PZT materials through a CVD process
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New Pb(IV) precursors for lead zirconate titanate (PZT) thin films were synthesized, and their solid-state structures were elucidated by single-crystal X-ray crystallography. First, tetraphenyl lead (Ph4Pb) was synthesized from the reaction of PbCl2 with the Grignard reagent, PhMgBr, by a published method. Two of the phenyl ligands in Ph4Pb were replaced by bromines, and then were substituted with bis(trimethylsilyl)amides (btsa) to yield Ph2Pb(btsa)2 (1), or with 2,2,6,6-tetramethyl-3,5-heptadiketonate (thd) ligands to yield Ph2Pb(thd)2 (2). Single crystals of these two new Pb(IV) precursors were obtained by recrystallization in hexane, and their chemical compositions were characterized by FT-IR and 1H NMR. In TG analyses, both compounds exhibited sharp decomposition curves, with major mass losses in the region of 200–250 °C. PZT films were fabricated from one of the newly prepared Pb(IV) precursors by an MOCVD process involving Ti(OiPr)4 and Zr(OPr)4, and the development of the perovskite phase with temperature was monitored by an XRD method.
- Kim, Euk Hyun,Moon, Cheong Won,Lee, Jung Gyu,Lah, Myoung Soo,Koo, Sang Man
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- Synthesis and Chemistry of Bis(borylphosphino)silanes and -germanes
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The reactions of Me2SiCl2, Ph2SiCl2, and Ph2GeCl2 with LiP(H)B(N(i)Pr2)2in a 1:2 ratio and the reaction of Ph2SiCl2 with LiP(H)B(N(i)Pr2)[N(SiM e3)2] in a 1:2 ratio give good yields of the respective diphosphinosilanes, Me2Si[P(H)B(N(i)Pr2)2]2, Ph2Si[P(H)B(N(i)Pr2)2]2, Ph2Ge[P(H)B(N(i)Pr2)2]2, and Ph2Si[P(H)B(N(i)Pr2)[N(SiMe3)2]]2. These species, when combined with BuLi in a 1:2 ratio, give lithium diphosphinosilanes and -germanes of the general type (DME.Li)2{[PB(NR2)2]2ER'2}. All of the species have been characterized by spectroscopic methods. The molecular structuresof three of the lithio compounds, (DME.Li)2{[PB(N(i)Pr2)2]2SiPh2} (11), (DME.Li)2{[PB(N(i)Pr2)N(SiMe3)2]2SiPh2} (15), and (DME.Li)2{[PB(N(i)Pr2 )2]2GePh2} (13), have been determined by X-ray diffraction techniques. 11 crystallized in the triclinic space group P1- with a = 11.071(2) ?, b = 14.937(3) ?, c = 18.080(4) ?, α = 91.31(3)°, β = 101.23(3)°, γ = 109.95(3)°, and Z = 2, and 13 crystallized in the triclinic space group P1- with a = 11.083(1) ?, b = 14.978(2) ?, c = 18.134(2) ?, α = 91.17(1)°,β = 101.43(1)°, γ = 110.05(1)°, and Z = 2. 15 crystallized in the monoclinic space group P21/n with a = 11.939(2) .ANG ., b = 24.516(3) ?, c = 21.572(3) ?, β = 101.52(1)°,and Z = 4. The reactions of the lithio compounds were surveyed with R2E Cl2 reagents. The metathesis reactions are sluggish, but the 1:1 reaction of (DME.Li)2{[PB(N(i)Pr2)2]2GePh2} with (t)Bu2SnCl2 gave the four-membered-ring compound Ph2GePB(N(i)Pr2)2Sn((t)Bu)2PB(N(i)Pr2)2. The 1:2 reaction of Me2(Cl)SiSi(Cl)Me2 with LiP(H)B(N(i)Pr2)2 yielded the (borylphosphino)silane [Me2SiP(H)B(N(i)Pr2)2]2.
- Chen, Tuqiang,Duesler, Eileen N.,Paine, Robert T.,Noeth, Heinrich
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p. 4993 - 4999
(2008/10/08)
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- Ueber Tetraaryl-Methan-Analoga in der Gruppe 14.III. Ar4Sn/Pb (Ar=Ph, p-, m-, o-Tol, 2,4-Xyl und 2,5-Xyl): Gegenueberstellung von Bindungslaengen und Winkeln, von NMR chemischen Verschiebungen und Kopplungskonstanten und von Schwingungsdaten
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The title compounds have been synthesized Grignard reactions or pyrolysis of diplumbanes respectively.The crystal structures of m-Tol4Pb and Ph4Pb (redetermination) have been determined.All eight compounds (Ph/Tol)4(Sn/Pb) are S4 symmetric and contracted along this unique axis.The 13C-NMR chemical shifts and the couplings 1J(119Sn/207Pb-13C) as well depend additively upon the methyl substituents.The ratios 1K(207Pb-13C):1K(119Sn-13C) of the reduced coupling constants are all near to 1.61; a comparison with values from the literature for alkyl, alkenyl and alkinyl substituents is given.The ratio δ(207Pb):δ(119Sn) results in 2.28.IR (700 down to 200 cm-1) and Raman (700 down to 50 cm-1) data are given.Key words: Tin; Lead; Group 14; Vibrational data; Nuclear magnetic resonance; Crystal structure
- Schneider-Koglin, Claudia,Mathiasch, Bernd,Draeger, Martin
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- Synthesis and some reactions of tris (pentafluorophenyl) antimony compounds
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(C6F5)3Sb has been found to react with interhalogens and halo-pseudohalogens, IX(X = Cl, Br, N3 and NCO), pseudohalogen (SCN), and elemental sulphur to give oxidative addition products (I-VI). (C6F5)3SbS(VI) may also be prepared by the reaction of (C6F5)3SbCl2 with H2S. Metathetical reactions of (C6F5)3SbCl2 with appropriate metallic salts yield covalent pentacoordinate disubstituted products (V, VII-XII) of the general formula, (C6F5)3SbY2 (Y = NCS, NCO, -ONCMe2, -ONCMePh -NCO(CH2)2CO and p-NO2C6H4OCO). Treatment of (C6F5)3SbCl2 with aqueous NaN3 gives the binuclear oxo-bridge compound, [(C6F5)3SbOSb(C6F5)3](N3)2·(III) and (IV) are also accessible by displacement reaction of (I) or (II) with the corresponding metallic salt. Molecular weight, conductance measurements, and IR spectra on the new organoantimony(V) derivatives have been obtained. Reductive cleavage reactions of (C6F5)3SbS with hexaaryldileads, Ar6Pb2(Ar = Phenyl, p-tolyl) produce (C6F5)3Sb and the corresponding bis(triaryllead) sulphide but treatment of (C6F5)3SbX2(X = NCO, Cl) with Ar6Pb2 gave Ar4Pb and Ar2PbX2 together with (C6F5)3Sb. (C6F5)3SbCl2 and bis(triorganotin)sulphides undergo exchange of anionic groups.
- Raj, Prem,Saxena,Singhal, Kiran,Ranjan, Ashok
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p. 251 - 258
(2008/10/08)
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- Multi Electron Ligands, VIII. Connection of the all-trans-1,5,9-Cyclododecatriene System with Additional Donor Groups
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Nine potential ligands (2 - 10) for transition metals were obtained from the well accessible all-trans-1,5,9-cyclododecatriene (ttt-CDT) by introduction of donor groups.The synthesis was achieved via ttt-3-bromo-CDT (1) and the hitherto unknown ttt-3-iodo-CDT (2).To the contrary, introduction of donor groups via nucleophilic ttt-CDT derivatives was successful in one case only (15). ttt-3-Lithio-CDT (13), obtained by organoelement-Li exchange, revealed to be extremely basic (quick deprotonation of diethyl ether at low temperature).In situ made Ni0 complexes of someof the new ligands failed to oligomerize or polymerize butadiene.
- Kauffmann, Thomas,Fauss, Waltraud
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p. 2330 - 2342
(2007/10/02)
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- New Reagents, XXX: Synthesis and Stability of Bis(triphenylplumbyl)methyllithium and Reactions with Alkyl Halides, Carbonyl Compounds, and Oxiranes
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Bis(triphenylplumbyl)methyllithium (2) is easily accessible by plumbyl-Li or Br-Li exchange from tris(triphenylplumbyl)methane (1b) and bromobis(triphenylplumbyl)methane (3), respectively.Due to its stability and high nucleophilicity 2 is a good reagent for the synthesis of bis(plumbyl)alkanes, -β-hydroxyalkanes, and -γ-hydroxyalkanes.
- Kauffmann, Thomas,Rensing, Alfons
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p. 380 - 390
(2007/10/02)
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- The Chemistry of (Cyclopentadienyl)phenyl-lead(IV) Compounds
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The yellow air-stable (cyclopentadienyl)phenyl-lead(IV) compounds, PbPh(4-n)(cp)n , have been synthesised by the reaction of the corresponding phenyl-lead(IV) chloride and lithium cyclopentadienide in diethyl ether.Crystals of PbPh3(cp) are monoclinic, space group P21/c, with a = 9.5426, b = 12.3843, c = 16.1714 Angstroem, β = 102.3358 degree, and Z = 4, and comprise discrete non-interacting molecules with a distorted tetrahedral geometry.The Pb-C(cp) bond distance is significantly longer than the Pb-C(Ph) distances , indicating a substantial weakening of this bond.The endocyclic C-C bonds of the cyclopentadienyl ring (which is planar) are consistent with a concentration of ?-electron density over the carbon atoms remote from the lead.Reaction of PbPh3(cp) with acetic acid, thiophenol, and imidazole proceeds with exclusive Pb-C(cp) bond cleavage affording PbPh3(O2CMe), PbPh3(SPh), and PbPh3(N2C3H3), respectively.Only PbPh4 was isolated from the reaction with 4-chlorophenol.The compound PbPh2(cp)2 decomposes on attempted sublimation at 60-70 deg C and 0.01 mmHg giving Pb(cp)2, whilst reaction with hidrogen chloride, carboxylic acids, and imidazole yields the corresponding diphenyl-lead(IV) derivative.Cleavage of all four Pb-C bonds occurs on reaction with thiols, when lead(II) thiolates are the products.Reaction with phenols yields products of composition n which presumably contain metal-metal bonds.The mechanisms of the reactions are discussed.
- Gaffney, Christine,Harrison, Philip G.
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p. 1055 - 1060
(2007/10/02)
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- ORGANOPLUMBIO COMPLEXES OF PLATINUM(II)
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The complex reacts with Pb2Ph6 to give cis-; this decomposes in solution to cis-, which may also be obtained from the ethylene complex and PbPh4.Lead compounds PbPhMe3 and PbPh3Br also give produc
- Al-Allaf, Talal A. K.,Butler, Gregory,Eaborn, Colin,Pidcock, Alan
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p. 335 - 344
(2007/10/02)
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