Si-Kernresonanzspektren und synthese von bromdisilanen und ioddisilanen

The syntheses of Bromodisilanes Br_nSi₂H_6−n and Iododisilanes I_nSi₂H_6−n (n = 1, 2, 3, 4, 5), starting from caryldisilanes Ar_nSi₂H_6−n (Ar = phenyl, -naphthyl, mesityl) are reported. The ²⁹Si-NMR-spectra of all compounds, including ²⁹Si²⁹Si-coupling constants, have been measured.

Zusammenfassung

Ausgehend von Aryldisilanen ArS₂H_6−n, (Ar = Phenyl, -Naphthyl, Mesityl) wurden die Bromdisilane Br_nSi₂H_6−n, und Ioddisilane I_nSi₂H_6−n, (n = 1, 2, 3, 4, 5) synthetisiert. Die ²⁹Si-NMR-Spektren aller Verbindungen, (eingeschlossen ²⁹Si²⁹Si-Kopplungskonstanten) wurden vermessen.     

Group 14 chalcogenides featuring a bicyclo[3.3.0]octane skeleton

Reactions of mixtures of Cl₂MeSiSiMeCl₂ (1) and Me₂MCl₂ (M=Si, Ge, Sn) with either H₂S/NEt₃ or Li₂E (E=Se, Te) yielded the bicyclo[3.3.0]octanes Me₂M(E)₂Si₂Me₂(E)₂MMe₂. A carbon containing analog, (CH₂)₅C(S)₂Si₂Me₂(S)₂C(CH₂)₅, was prepared from 1 and (CH₂)₅C(SH)₂. Crystal structures of three of these compounds were determined and the observed conformations of the bicyclo[3.3.0]octane skeletons compared with results of density functional theory calculations. Another class of silchalcogenides featuring a bicyclo[3.3.0]octane skeleton, E(Me₂Si)₂Si₂Me₂(SiMe₂)₂E, was formed from the doubly branched hexasilane (ClMe₂Si)₂Si₂Me₂(SiMe₂Cl)₂ and H₂S/NEt₃ or Li₂E. All products were characterized by multinuclear NMR (¹H, ¹³C, ²⁹Si, ⁷⁷Se, ¹¹⁹Sn, and ¹²⁵Te).     

La-NMR-spektroskopie an allyllanthan(III)-komplexen

¹³⁹La-NMR chemical shifts were measured for several anionic complexes of formulae Li(C₄H₈O₂)_3/2 [La(ν³-C₃H₅)₄], [Li(C₄H₈O₂)₂][Cp′_nLa(ν³-C₃]H₅)_4−n] (Cp′ = Cp(ν⁵-C₅H₅); n = 1, 2 and Cp′ = Cp * (ν⁵-C₅Me₅); N = 1) and Li[R_nLa(ν³-C₃H₄)₄−n] (R = N(SiMe₃)₂; n = 1, 2 and R = CCsIMe₃; n = 4), as well as for neutral compounds for formulae La(ν³-C₃H₅)₃L_n (L = (C₄H₈O₂)_1.5, (HMPT)₂, TMED), Cp′_nLa(ν³-C₃H₅)_3−n (Cp′= Cp(ν⁵-Cp₅H₅), Cp *(ν⁵-C₅Me₅); n = 1, 2) and La(ν³-C₃H₂)₂X(THF)₂ X = Cl, Br, I). Typical ranges of the ¹³⁹La-NMR chemical shifts were found for the different types of complex independent of number and kind of organyl groups directly bonded to lanthanum.

Zusammenfassung

¹³⁹La-NMR-Spektroskopie wurde an einer Reihe anionischer Allyllanthanat(III)-Komplexe der Zusammensetzung ]- [La)ν³-C₃H₅)₄, [Li(C₄H₈)₂][Cp′_nLa(ν³-C₃H₅)_4−n(Cp′ = Cp(ν⁵-C₅H₅); n = 1, 2 und Cp′ = Cp * (ν⁵-C₅Me₅); N = 1) und Li[R_nLa(ν³-C₃H₅)_4−n (R = B(SiMe₃)₂; n = 1, 2 und R = CCSiMe₃; n = 4 sowie neutraler Allyllanthan(III)-Komplexe der Zusammensetzung La(ν³-C₃H₅)₃L_n (L_n = (C₄H₈O₂)_1.5, (HMPT)₂, TMED), Cp′_n, La(ν³-C₃H₅)_3−n (Cp′ = Cp(ν⁵-C₅H₅), Cp * (ν⁵- Cp₅Me₅); n = 1, 2) und La(ν³-Cp₃H₅)₂X(THF)₂ (X = Cl, Br, I) durchgefürt. In Abhängikeit von der Anzahl und der Art der am Lanthan gebundenen Gruppen wurden für die verschieden Komplextypen charakteristische Resonanzbereiche ermittelt.     

2,2'-联吡啶二氢双三碘基盐(2,2'-bipyH2)(I3)2的合成、晶体结构和谱学性质

合成了标题化合物并测定其晶体结构.晶体属三斜晶系,P1空间群,α=0.80284(8)nm,b=0.95993(6)nm,c=0.71660(9)nm,α=102.016(9)°,β=111.933(9)°,γ=101.650(8)°,V=0.4767(1)nm³,Z=1,D_c=3.21g·cm^-3,F(000)=404,μ(MoK_a)=98.77cm^-1.晶体中存在反式平面型的(2,2'-bipyH₂)²⁺阳离子和线性的I₃^-阴离子.晶体由[(2,2'-bipyH₂)(I₃)₂]_∞链堆积而成,同一层的链间存在N-H···I氢键,氢键键长N···I为0.349nm.用UV-Vis光谱和¹H NMR谱对标题化合物进行了表征.     

四甲基双硅桥联环戊二烯基稀土金属有机配合物的合成及[Me4Si2(C5H4)2Sm(μ-Cl)(THF)]2的晶体结构研究

四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在THF溶剂中反应合成了标题配合物Me₄Si₂(C₅H₄)₂LnCl[Ln:3Nd,4Sm,5Gd,6Y]和配合物Me₄Si₂(C₅H₄):Ln(C₅H₅)(THF)n[Ln:1La,n=1;2Pr,n=0].通过元素分析、¹HNMR、13CNMR和MS确证了配合物的结构,在THF溶液中重结晶获得配合物4的单晶,x射线衍射证明晶体结构为二聚体,4为单斜晶系,空间群为P2₁/c,晶体学数据a=1.2982(3)nm,b=1.2269(3)nm,c=1.3681(2)nm,β=96.79(2)°,V=2.162(1)nm³,Z=2,D_x=1.53g/cm³,偏差因子R=0.068.     

Reactions of Lewis bases with tetrakisdiphenylamide uranium(IV)

The coordinatively unsaturated uranium(IV) complex U[N(C₆H₅)₂]₄ has been prepared via the stoichiometric reaction of diphenylamine with [(Me₃Si)₂N]₂ H₂. U[N(C₆H₅)₂]₄ coordinates Lewis bases such as Et₂O, THF, pyridine or (EtO)₃PO, based on electronic absorption spectroscopy and ¹H NMR studies. Exchange between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄(L), where L is THF or pyridine, is rapid on the NMR time-scale between 307 and 323 K. Measurement of equilibrium constants for L = THF provides ΔH and ΔS values of −60 kJ mol⁻¹ and −1.8 × 10² J K⁻¹ mol⁻¹, respectively. U[N(C₆H₅)₂]₄ coordinates and binds (EtO)₃PO much more tightly (K_eq = & > 10⁴ M⁻¹) than THF or pyridine with the exchange rate between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄[OP(OEt)₃] being close to the NMR time-scale.     

Novel iodoammonium cations: Synthesis and characterization of o-C6H4(NH2)2IX (X = I, AsF6, AlI4)

The new iodoammonium salts o-C₆H₄(NH₂)₂I⁺I⁻ (1) and o-C₆H₄(NH₂)₂I⁺ AsF₆⁻ (2) were prepared by reaction of o-phenylene diamine with I₂ or I₃⁺AsF₆⁻, respectively. Compound 1 reacts with AlI₃ yielding quantitatively the corresponding tetraiodoaluminate o-C₆H₄(NH₂)₂I⁺AlI₄⁻ (3). The species were characterized by chemical analysis, vibrational (IR and Raman) and temperature-dependent ¹H NMR spectropscopy. Direct evidence for a N---I bond was found in the Raman spectra of 1, 2 and 3 (ν(NI) = 599–600 cm⁻¹).     

Preparation and study of cyclic polynuclear ferrocenes derived from (C6H5)2PCH2CH2Si(CH3)2C5H4Li as a bridging ligand

The synthesis of the potential bridging ligand (C₆H₅)₂PCH₂CH₂Si(CH₃)₂C₅H₄ (3) is described. The ferrocene (6 derived from 3 has been found to form macrocyclic complexes with metal fragments NiCl₂, NiBr₂, and Co₂(CO)₆. Although monomeric, bimetallic products might have been expected based upon the reduced steric demands of ligand 3 relative to an analogous ligand, (C₆H₅)₂PCH₂Si(CH)₃)₂C₅H₄ (1), it appears that the increased flexibility in 3 is the overriding factor leading to a preference for inter- rather than intramolecular coordination of the second phosphine function in 6.     

Thirty years of organometallic aryldiazenido arylazo derivatives

The aryldiazenido ligands provide the fourth member of the isoelectronic series CO, NO⁺, RNC, RN₂⁺ of ligands for transition metal complexes. The first aryldiazenido metal complex was reported in 1964 when p-CH₃OC₆H₄N₂Mo(CO)₂C₅H₅ was prepared by the reaction of NaMo(CO)₃C₅H₅ with p-CH₃OC₆H₄N₂⁺BF₄⁻. This review surveys the development of organometallic aryldiazenido chemistry since that time. Such organometallic aryldiazenido derivatives, including RN₂M(CO)₂C₅H₅, RN₂M(CO)₂(Pz₃BH) (M = Cr, Mo, W), [(η⁶-Me₆C₆)Cr(CO)₂N₂Ar]⁺, [(MeC₁₅H₄)M′(CO)₂N₂Ar]⁺ M′ = Mn, Re), [trans-PhN₂Fe(CO)₂(PPh₃)₂]⁺, and PhN₂M′(CO)₂(PPh₃)₂(PPh₃)₂ can be obtained by reactions of arenediazonium salts with suitably chosen transition metal nucleophiles. Analogous methods cannot be used to prepare alkyldiazenido transition metal complexes because of the instability of alkyldiazonium salts. However, the alkyldiazenido derivatives RCH₂N₂M(CO)₂C₅H₅ (R = H or Me₃Si) can be obtained from HM(CO)₃C₅H₅ and the corresponding diazoalkanes. Important aspects of the chemical reactivity of RN₂M(CO)₂Q derivatives (Q = C₅H₅, Pz₃BH) include CO substitution reactions, coordination of the second nitrogen in the RN₂ ligand to give heterobimetallic complexes such as C₅H₅Mo(CO)₂(μ-NNC₆H₄Me)(CO)₂C₅H₅, oxidative addition rections with X₂ X = Cl, Br, I), SnX₄, RSSR, and CINO, and reactions with further RN₂⁺ to give bis(aryldiazenido) derivatives (RN₂)₂MQL⁺ (L = CO, X⁻, etc.). Dearylation of an aryldiazenido ligand to a dinitrogen ligand can be effected by reaction of [(MeC₅H₄)M′(CO)₂N₂Ar]⁺ with certain nucleophiles to give (MeC₅H₄)M′(CO)₂N₂.     

Synthesis and properties of alkyldicyclopentadienyl-vanadium(III) compounds

The compounds Cp₂VR (R = CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, n-C₅H₁₁, CH₂C(CH₃)₃ or CH₂Si(CH₃)₃) have been prepared from Cp₂ VCl and RMgX in n-pentane. The air-sensitive compounds are stable at room temperature, but decompose between 65 and 138°C. The thermal stability decreases in the order R = CH₃ CH₂Si(CH₃)₃ > C₂H₅ > CH₂C(CH₃)₃ > n-C₅H₁₁ > n-C₄H₉ > n-C₃H₇. Compounds with R = i-C₃H₇ or t-C₄H₉ could not be obtained.     

CIDNP of Diecyl Peroxides Studies on the Kinetics of Decomposition of Diacyl Peiroxides Ⅷ in the Decomposition of Diacyl Peroxides

H CIDNP spectra recorded during the decomposition of aliphatic diacyl peroxides ((RCOO)2 R=n-C H (1),n-c5H11(2)) in ODCB in the presence of scavengers,such as I2C2H5I,(CH3)2CHI,and CH2=CHCH2 Br show multiplet effect for the scavenged products,RX(X=Br,I) and for disproportionation products,R-H.The reactionmechanism is discussed in terms of radical pair theory.     

三(三甲基硅)环戊二烯与六羰基钼的反应

三(三甲基硅)环戊二烯与六羰基钼在二甲苯中回流8h,反应停留在生成中间物η⁵-[(Me₃Si)_NC₅H_5-n]Mo(CO)₃H(n=2,3)(I)的阶段.不经分离,I随即分别与CCl₄·NBS及MeI反应,生成其相应的钼卤化物η-⁵[(Me₃Si)_NC₅H_5-n]Mo(CO)₃X[n=3,X=Cl(1),Br(2),I(3);n=2,X=Cl(4),Br(5),I(6)].4-6是由于茂环上脱掉1个Me₃Si基.经元素分析和IR及¹H NMR谱表征了化合物1-6的结构,并用X射线衍射测定了1的晶体结构.     

含芳香双酯高效催化剂进行丙烯聚合及其动力学的研究

采用多种芳香双酯作为电子给予体制备了丙烯聚合高效催化剂,该催化剂具有高活性、聚合反应平稳、产物等规度高等特征.研究了多种芳香双酯和外加各种烷基硅氧烷对丙烯聚合的作用,测定了聚合反应动力学曲线,确定了聚合动力学方程.用扫描电镜研究了催化剂的形态,表明双酯组份能使催化剂结合得较紧密;对聚合产物的结构用DSD、红外光谱进行了表征.     

Group 4 metallacarboranes of constrained geometries derived from B(cage)- and C(cage)-silylamido-substituted carborane ligands: a synthetic and structural investigation

The reactions of RNHSi(Me)₂Cl (1, R=t-Bu; 2, R=2,6-(Me₂CH)₂C₆H₃) with the carborane ligands, nido-1-Na(C₄H₈O)-2,3-(SiMe₃)₂-2,3-C₂B₄H₅ (3) and Li[closo-1-R′-1,2-C₂B₁₀H₁₀] (4), produced two kinds of neutral ligand precursors, nido-5-[Si(Me)₂N(H)R]-2,3-(SiMe₃)₂-2,3-C₂B₄H₅, (5, R=t-Bu) and closo-1-R′-2-[Si(Me)₂N(H)R]-1,2-C₂B₁₀H₁₀ (6, R=t-Bu, R′=Ph; 7, R=2,6-(Me₂CH)₂C₆H₃, R′=H), in 85, 92, and 95% yields, respectively. Treatment of closo-2-[Si(Me)₂NH(2,6-(Me₂CH)₂C₆H₃)]-1,2-C₂B₁₀H₁₁ (7) with three equivalents of freshly cut sodium metal in the presence of naphthalene produced the corresponding cage-opened sodium salt of the “carbons apart” carborane trianion, [nido-3-{Si(Me)₂N(2,6-(Me₂CH)₂C₆H₃)}-1,3-C₂B₁₀H₁₁]³⁻ (8) in almost quantitative yield. The reaction of the trianion, 8, with anhydrous MCl₄ (M=Ti and Zr) in 1:1 molar ratio in dry tetrahydrofuran (THF) at −78 °C, resulted in the formation of the corresponding half-sandwich neutral d⁰-metallacarborane, closo-1-M[(Cl)(THF)_n]-2-[1′-η¹σ-N(2,6-(Me₂CH)₂C₆H₃)(Me)₂Si]-2,4-η⁶-C₂B₁₀H₁₁ (M=Ti (9), n=0; M=Zr (10), n=1) in 47 and 36% yields, respectively. All compounds were characterized by elemental analysis, ¹H-, ¹¹B-, and ¹³C-NMR spectra and IR spectra. The carborane ligand, 7, was also characterized by single crystal X-ray diffraction. Compound 7 crystallizes in the monoclinic space group P2₁/c with a=8.2357(19) Å, b=28.686(7) Å, c=9.921(2) Å; β=93.482(4)°; V=2339.5(9) ų, and Z=4. The final refinements of 7 converged at R=0.0736; wR=0.1494; GOF=1.372 for observed reflections.     

Preparation and characterization of ruthenium(II), rhodium(III) and iridium(III) complexes of isocyanide bearing the azo group

Reactions of [(η⁶-arene)RuCl₂]₂ (1) (η⁶-arene=p-cymene (1a), 1,3,5-Me₃C₆H₃ (1b), 1,2,3-Me₃C₆H₃ (1c) 1,2,3,4-Me₄C₆H₂(1d), 1,2,3,5-Me₄C₆H₂ (1e) and C₆Me₆ (1f)) or [Cp*MCl₂]₂ (M=Rh (2), Ir (3); Cp*=C₅Me₅) with 4-isocyanoazobenzene (RNC) and 4,4′-diisocyanoazobenzene (CN–R–NC) gave mononuclear and dinuclear complexes, [(η⁶-arene)Ru(CNC₆H₄N=NC₆H₅)Cl₂] (4a–f), [Cp*M(CNC₆H₄N=NC₆H₅)Cl₂] (5: M=Rh; 6: M=Ir)_, [{(η⁶-arene)RuCl₂}₂{μ-CNC₆H₄N=NC₆H₄NC}] (8a–f) and [(Cp*MCl₂)₂(μ-CNC₆H₄N=NC₆H₄NC)}] (9: M=Rh; 10: M=Ir)_, respectively. It was confirmed by X-ray analyses of 4a and 5 that these complexes have trans-forms for the ---N=N--- moieties. Reaction of [Cp*Rh(dppf)(MeCN)](PF₆)₂ (dppf=1,1′-bis (diphenylphosphino)ferrocene) with 4-isocyanoazobenzene gave [Cp*Rh(dppf)(CNC₆H₄N=NC₆H₅)](PF₆)₂ (7), confirmed by X-ray analysis. Complex 8b reacted with Ag(CF₃SO₃), giving a rectangular tetranuclear complex 11b, [{(η⁶-1,3,5-Me₃C₆H₃)Ru(μ-Cl}₄(μ-CNC₆H₄N=NC₆H₄NC)₂](CF₃SO₃)₄ bridged by four Cl atoms and two μ-diisocyanoazobenzene ligands. Photochemical reactions of the ruthenium complexes (4 and 8) led to the decomposition of the complexes, whereas those of 5, 7, 9 and 10 underwent a trans-to-cis isomerization. In the electrochemical reactions the reductive waves about −1.50 V for 4 and −1.44 V for 8 are due to the reduction of azo group, [---N=N---]→[---N=N---]²⁻. The irreversible oxidative waves at ca. 0.87 V for the 4 and at ca. 0.85 V for 8 came from the oxidation of Ru(II)→Ru(III).     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

A study of ortho- and para-siloxyanilines for the synthesis of mono-, bi-, and tetra-nuclear early transition metal–imido complexes

The siloxyanilines o-Me₃SiOC₆H₄NH₂ (1) and p-RMe₂SiOC₆H₄NH₂ (R=H (2); R=Me (3)), and their N-silylated derivatives p-Me₃SiOC₆H₄NHSiMe₃ (4) and p-Me₃SiOC₆H₄N(SiMe₃)₂ (5) have been prepared from ortho- or para-aminophenol and used in the synthesis of imido complexes. Thus, binuclear [{Ti(η⁵-C₅H₅)Cl}{μ-NC₆H₄(p-OSiMe₃)}]₂ (6) and mononuclear [TiCl₂{NC₆H₄(p-OSiMe₃)}(py)₃] (7) imido complexes have been obtained from the reaction of 3 and [Ti(η⁵-C₅H₅)Cl₃] or [TiCl₂(N^tBu)(py)₃], respectively. In contrast, the reaction of 1 with TiCl₄ and ^tBupy affords the titanocycle [TiCl₂{OC₆H₄(o-NH)---N,O}(^tBupy)₂] (8). Compound 5 has also been used to prepare the niobium imide complex [NbCl₃{NC₆H₄(p-OSiMe₃)}(MeCN)₂] (9), by its reaction with NbCl₅ in CH₃CN. These findings have been applied to the synthesis of polynuclear systems. Thus, chlorocarbosilane Si[CH₂CH₂CH₂Si(Me)₂Cl]₄ (CS–Cl) has been functionalized with the ortho- and para-aminophenoxy groups to give 10 and 11, respectively. The use of 11 has allowed the formation of the tetranuclear compound 12. Attempts to synthesize terminal imido titanium complexes from 10 and TiCl₄ in the presence of ^tBupy and Et₃N, give complex 8 and carbosilane CS–Cl.     

碳锗双桥连二环戊二烯与羰基铁的反应

碳锗双桥连二环戊二烯(Me₂C)(Me₂Ge)(C₅H₄)₂(1)与五羰基铁在回流甲苯及二甲苯中的反应,得到正常的Fe-Fe键化合物(Me₂C)(Me₂Ge)[(η⁵-C₅H₃)Fe(CO)]₂(μ-CO)₂(3)和脱锗桥产物(Me₂C)[(η⁵-C₅H₄)Fe(CO)]₂(μ-CO)₂(4)以及一个结构新颖的化合物(Me₂C)[(η⁵-C₅H₃)[(Me₂Ge)Fe(CO)₂](η¹,η⁵-C₅H₃)[Fe(CO)₂](2).用X射线衍射分析測定了化合物3的晶体结构,并提出了可能的生成机理.     

ansa-Metallocene derivatives XXXIII. 2-Dimethylamino-substituted bis-indenyl zirconium dichloride complexes with and without a dimethylsilyl bridge: syntheses, crystal structures and properties in propene polymerization catalysis

Bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (2-(CH₃)₂N-C₉H₆)₂ZrCl₂, and dimethylsilyl-bridged bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂, were prepared by reaction of the corresponding ligand lithium salts with ZrCl₄ in toluene. Diffractometric structure determinations reveal C₂-symmetric complex geometries for both complexes. An increased electron density at the Zr center of the dimethylamino-substituted complexes is indicated by reduction potentials which are 0.3–0.4 V more negative than those of their unsubstituted analogs. When activated with methyl aluminoxane in toluene solution, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂ catalyzes the polymerization of propene to polymers with a microstructure comparable with that of polymers produced with other Me₂Si-bridged bis(indenyl)ZrCl₂ complexes, but with a substantially increased fraction of i-propyl end groups derived from alkyl exchange between Zr-polymer and Al---Me species.     

Komplexe mit kohlenstoffsulfiden und -seleniden als liganden : X. Synthese und kristallstruktur von C5H5(PMe3)Co(μ-CS)2CoC5H5: Ein zweikernkomplex mit unsymmetrischen Co(CS)Co-brückenbindungen

The complex C₅H₅(PMe₃)Co(μ-CS)₂CoC₅H₅ (I) is formed by the reaction of C₅H₅Co(PMe₃)CS and CH₂I₂. The X-ray structure analysis shows an unsymmetrical non-planar Co₂C₂-skeleton with different Co---C bond lengths. The Co---Co distance is 239.2 pm. Compound I thus represents a new example of binuclear (18 + 16)-electron complexes in which the more electron-rich metal atom forms a donor bond to the more electron-poor counterpart. The reaction of I with ligands such as P(NMe₂)₃ does not lead to bridge cleavage indicating the stability of the Co(CS)₂Co-framework.