The coordinative properties of the ligands Ph2ECH2EPh2 (E = P,As, Sb) in carbonylvanadium complexes,and the molecular structure of η5-C5H5V(CO)3As2Ph4

Photo-reaction between the ligands Ph₂ECH₂EPh₂ (E = P: dppm, E = As: dpam, E = Sb: dpsm), L, and the vanadium complexes η⁵-C₅H₅V(CO)₄ and [Et₄N][V(CO)₆] yields monosubstituted mononuclear (dpsm) and dinuclear, ligand-bridged complexes (dpam, dpsm). With dppm, the final products are disubstituted chelate complexes, but monosubstituted mono- and dinuclear species are formed as intermediates.The shielding of the ⁵¹V nucleus decreases in the series dpsm > dppm > dpam and {M(CO)_n} > {M(CO)_n?1} L > {M(CO)_n?1}₂μ-L > {M(CO)_n?2}dppm ({M(CO)_n}[V(CO)₆]^?, η⁵-C₅H₅V(CO)₄). The half-widths of the NMR signals are greater for dinuclear than for mononuclear complexes.The crystal and molecular structures of η⁵-C₅H₅V(CO)₃As₂Ph₄ have been determined. The compound crystallizes in the space group P2₁/c with a = 1347.8, b = 1020.0, c = 2085.2 pm and β = 82.3°. Due to steric crowding, the ⁵¹V shielding is low composed to that of {η⁵-C₅H₅V(CO)₃}₂μ-dpam.     

Crystal and molecular structures of (η-xanthene)- (η-cyclopentadienyl)iron(II) hexafluorophosphate and (η-2-methylthianthrene)(η-cyclopentadienyl)iron(II) hexafluorophosphate

The neutral complexes (η⁵-C₅H₅NiXL (X = Cl, L = PPh₃ (I); L = PCy₃ (II); X = Br, L = PPh₃ (III); L = PCy₃ (IV); X = I, L = PPh₃ (V); L = PCy₃ (VI)) have been obtained by treating NiX₂L₂ with thallium cyclopentadienide. The same reaction in the presence of TlBF₄ gives cationic derivatives [(η⁵-C₅H₅)NiL₂]BF₄ (L = 2PPh₂Me (VII); L = dppe (VIII)), whereas mononuclear complexes containing two different ligands (L₂ = PPh₃ + PCy₃ (IX)) or dinuclear [(η⁵-C₅H₅)Ni(PPh₃)]₂dppe(BF₄)₂ (X) are obtained from the reaction of III with TlBF₄ in the presence of a different ligand. Reduction of cationic complexes with Na/Hg gives very unstable nickel(I) derivatives (η⁵-C₅H₅)NiL₂, which could not be isolated purely. Similar reduction of neutral complexes under CO gives a mixture of decomposition products containing [(η⁵-C₅H₅)Ni(CO)]₂ and nickel(o) carbonyls, whereas in the presence of acetylenes, dinuclear [(η⁵-C₅H₅)Ni]₂(RCCR′) (R = R′ = Ph; R = Ph, R′ = H) are obtained.     

Transition metal nitrosyls as nitrosylation agents : II.Photo-nitrosylation of η5-C5H5V(CO)3L(L = CO,Pz3) by [Co(NO)2Br]2

η⁵-C₅H₅V(NO)₂CO is prepared in 40% yield by the photo-reaction between η⁵-C₅H₅V(CO)₄ and [Co(NO)₂Br]₂.η⁵-C₅H₅V(NO)₂CO reacts by an S_N1 mechanism with various phosphines PZ₃ to yield η⁵-C₅-H₅V(NO)₂PZ₃. The phosphine complexes are also obtained by photo-induced ligand interchange between η⁵-C₅H₅V(CO)₃PZ₃ and [Co(NO)₂Br]₂, or η⁵-C₅H₅V(CO)₄ and Co(NO)₂Br(PZ₃). In all cases, the main cobalt species formed is Co(NO)(CO)₃. While the one-bond vanadiumphosphorus coupling constants of most of the phosphine complexes are virtually the same (ca 410 Hz),the chemical shift values δ(⁵¹V) (?1328 to ?973 ppm rel. VOCl₃) decrease in the order PF₃ > CO > P(OR)₃ > P(alkyl)₃ > PPh₃ > PPh(NEt₂)₂, reflecting the decreasing π-acceptor ability of the ligands. δ(⁵¹V) also decreases in the series of alkylphosphines PR₃ (R = Me, Et, Prⁿ, Buⁱ, Prⁱ, BU^t) as the cone angle of PR₃increases.     

Synthesis and structure of chiral-at-metal complexes with the ligand (S)-2-[(Sp)-2-(diphenylphosphino)ferrocenyl]-4-isopropyloxazoline

Half-sandwich complexes of formula [(ηⁿ-ring)MClL]PF₆ [L = (S)-2-[(S_p)-2-(diphenylphosphino)ferrocenyl]-4-isopropyloxazoline; (ηⁿ-ring)M = (η⁵-C₅Me₅)Rh; (η⁵-C₅Me₅)Ir; (η⁶-p-MeC₆H₄iPr)Ru; (η⁶-p-MeC₆H₄iPr)Os] have been prepared and spectroscopically characterised. The molecular structures of the rhodium and iridium compounds have been determined by X-ray crystallography. The related solvate complexes [(η⁵-C₅Me₅)ML(Me₂CO)]²⁺ (M = Rh, Ir) are active catalysts for the Diels-Alder reaction between methacrolein and cyclopentadiene.     

Application of electron-transfer chain catalysis: preparation of bridged 〚{(η5-C5H5)Fe(CO)2}2(μ-diphosphine)2+〛 complexes without chelated 〚(η5-C5H5)Fe(CO)(η2-diphosphine)+〛 byproducts

The ligand substitution by diphosphine L–L on (η⁵-C₅H₅)Fe(CO)₂I usually results in the chelated 〚(η⁵-C₅H₅)Fe(CO)(η²-L–L)⁺〛〚I^–〛 product exclusively. One could suppress the chelated complexes and selectively prepare the bridged 〚{(η⁵-C₅H₅)Fe(CO)₂}₂(μ-L–L)²⁺〛 complexes by application of the electron-transfer chain catalysis with a chemical initiation. Introducing a catalytic amount of reductant at low temperature to the mixture of 2:1 (η⁵-C₅H₅)Fe(CO)₂I/L–L in THF selectively produces the bridged complexes in 78–93% isolated yields where L–L is Ph₂P(CH₂)_nPPh₂, n = 1–4, or (η⁵-C₅H₄PPh₂)₂Fe.     

The synthesis and 1H NMR study of vinyl organometallic monomers: (η5-C5H4CHCH2)M(CO)2(NO) (M = Cr,Mo, W) and (η5-C5H4CHCH2)M(CO)2 (M = Co,Rh, Ir)

A reaction between 6-methylfulvene and lithium diisopropylamide in THF solution produces vinylcyclopentadienyllithium in yields of 85–95%. The ¹H NMR spectrum of this air-sensitive organlithium reagent has been recorded in THF-d₈. Reactions of vinylcyclopentadienyllithium with Group VIB metal hexacarbonyls followed by treatment with N-methyl-N-nitroso-p-toluenesulfonamide afford the new vinyl organometallic monomers (η⁵-C₅H₄CHCH₂)M(CO)₂(NO) (M = Mo, W). Vinylcyclopentadienyllithium also serves as a convenient precursor to a series of (η⁵-vinylcyclopentadienyl)dicarbonylmetal monomers of cobalt, rhodium, and iridium. The ¹H NMR spectra of these vinylcyclopentadienylmetal derivatives have been compared as a function of the metal.     

Metallorganische lewis-säuren; metallkomplexe mit schwach koordinierten anionischen liganden: XIII. Nachweis der koordination von tetrafluoroborat in carbonylmolybdän- und -wolfram-komplexen durch 19F- und 31P-NMR-spektroskopie

In the tetrafluoroborato complexes (η⁵-C₅H₅)(CO)₂LMFBF₃ (M = Mo, W; L = CO, PPh₃, P(OPh)₃) and (η⁵-C₉H₇)(CO)₃WFBF₃ the coordinated fluorine atom and the terminal F atoms of the BF₄ ligand can be distinguished by their ¹⁹F NMR signals. ¹⁹F and ³¹P NMR spectra of (η⁵-C₅H₅)(CO)₂P(OPh)₃WFBF₃ allow to establish cis → trans isomerization at elevated temperatures as well as rapid rotation of the coordinated BF₄ ligand.     

Novel complexes of manganese with phenylvinylidene as a ligand

Three novel stable complexes of manganese were prepared by interaction of [(η⁵-C₅H₅)Mn(CO)₂ (THF)] with phenylacetylene. X-ray structure analysis of two of the complexes established the presence of a phenylvinylidene ligand. In [(η⁵-C₅H₅Mn(CO)₂(CCHPh)] this ligand forms an unusual double MnC bond and in [(η⁵-C₅H₅)Mn₂(CO)₄(CCHPh)] it acts as a bridge strengthening the MnMn bond.     

Preparation and Ir, 31P,and 93Nb NMR spectroscopic investigation of phosphine derivatives of η5-C5H5Nb(CO)4

UV irradiation of η⁵-C₅H₅Nb(CO)₄ in the presence of the phosphine ligands L (L = 2 PEt₃, Ph₂P(CH₂)₂PPh₂ (p₂(n), n = 1–5), cis-Ph₂PCH=CHPPh₂ (c-dpe)), and the mixed arsine-phosphine ligands Ph₂AsCH₂CH₂PPh₂ (arphos) and o-C₆H₄(AsPh₂)(PPh₂) (pab) yields the well defined complexes cis-[η⁵-C₅H₅Nb(CO)₂L]. The monosubstituted species η⁵-C₅H₅Nb(CO)₃L have been characterized spectroscopically. P₂Ph₄ forms mono- and dinuclear, mono- and biligate carbonylniobium complexes.Shielding of the ⁹³Nb nucleus increases in the sequences (i) Ph₂As- < Ph₂P-, (ii) chelate 4-ring < chelate 5-ring and (iii) η⁵-C₅H₅Nb(CO)₂L < η⁵-C₅H₅Nb(CO)₃L < η⁵-C₅H₅Nb(CO)₄, and ³¹P coordination shifts decrease in the order c-dpe > pab > arphos > p₂(2) > p₂(5) > p₂(4) ～ PEt₃ > p₂(3) > p₂(1). The trends generally parallel those for the corresponding NMR parameters of the vanadium complexes. Paramagnetic contributions to the overall shielding are smaller for the ⁹³Nb than for the ⁵¹V nucleus, and this is explained in terms of increased covalency and decreased π-interaction in the niobium complexes.     

Group V complexes of the tricarbonyl(η-cycloheptatrienylium)molybdenum cation and their reduction to monosubstituted derivatives of tricarbonyl(1-6-η-cycloheptatriene)molybdenum

Reaction of [(η-C₇H₇)Mo(CO)₃][PF₆] with certain Group V donor ligands afforded monosubstituted complexes [(η-C₇H₇)Mo(CO)₂L][PF₆] (L = P(OPh)₃, PPh₃, PPh₂Me, PPhMe₂, AsPh₃, SbPh₃). These were reduced by NaBH₄ to the corresponding cycloheptatriene complexes (1-6-η-C₇H₈)Mo(CO)₂L. In addition, the preparation of alkylcycloheptatriene complexes (1-6-η-C₇H₇R)Mo(CO)₂L (R = Me, L = P(OPh)₃, PPh₃, PPh₂Me; R = t-Bu, L = PPh₃) is described. Spectroscopic properties, including ¹³C NMR, are reported.     

Photochemical and thermal reactions of η5-cyclopentadienyltetracarbonylvanadium and bis(pentafluorophenyl)acetylene

The photolysis of (η⁵-C₅H₅)V(CO)₄ in the presence of one or two equivalents of bis(pentafluorophenyl)acetylene yields (η⁵-C₅H₅)V(CO)₂(C₆F₅CCC₆F₅). One carbon monoxide ligand in this acetylene adduct can be photochemically displaced by triphenylphosphine to yield (η⁵-C₅H₅)V(CO)[P(C₆H₅)₃](C₆F₅CCC₆F₅). This complex is also obtained by the photolysis of (η⁵-C₅H₅)V(CO)₃P(C₆H₅)₃ in the presence of bis(pentafluorophenyl)acetylene. In vacuo, melt-phase thermolysis of (η⁵-C₅H₅)V(CO)₂(C₆F₅CCC₆F₅) and bis(pentafluorophenyl)acetylene produces (η⁵-C₅H₅)V(CO)(C₆F₅CCC₆F₅)₂. This diacetylenic complex as well as the perfluorinated organic compounds 2,3,5,6-tetrakis(pentafluorophenyl)-1,4-benzoquinone, 2,3,4,5-tetrakis(pentafluorophenyl)cyclopentadienone and 2,3,4,5,6,7-hexakis(pentafluorophenyl)cycloheptatrienone are also obtained from thermal reactions of (η⁵-C₅H₅)V(CO)₄ and bis(pentafluorophenyl)acetylene in solution. Photolysis of (η⁵-C₅H₅)V(CO)(C₆F₅CCC₆F₅)₂ in the presence of carbon monoxide produces (η⁵-C₅H₅)V(CO)₂(C₆F₅CCC₆F₅). The photochemical and thermal reactions of bis(pentafluorophenyl)acetylene and (η⁵-C₅H₅)V(CO)₄ are compared and contrasted with similar reactions of diphenylacetylene and (η⁵-C₅H₅)V(CO)₄.     

Die thermische reaktion von C5H5(CO)2FeNa mit benzimidchloriden C6H5(Cl)CNR

η⁵-C₅H₅(CO)₂FeNa reacts with the benzimide chlorides C₆H₅(Cl)CNR (R  CH(CH₃)₂, C₆H₅) in boiling THF to give the η¹-iminoacyl complexes η⁵-C₅H₅ (CO)₂Fe[η¹-C(C₆H₅)NR]. Alternatively, the new Fe complexes [η⁵-C₅H₅(CO)Fe$\text{C(C}{}_6\text{H}{}_5\text{)N(CH}{}_3\text{)C(C}{}_6\text{H}{}_5\text{)N}$CH₃PF₆ (IV) and [η⁵-C₅H₅(CO)₂FeC(C₆H₅)N(CH₃)C(C₆H₅)NCH₃]PF₆ (V) are formed under the same conditions, if R  CH₃. Hudrolysis of the CN single bond of the ligand in V, not stabilized by a chelate effects as in IV, results in the formation of [η⁵-C₅H₅(CO)₂FeC(C₆H₅)NHCH₃]PF₆ (VII). Reaction of η⁵-C₅H₅(CO)₂ with N-benyzylbenzimido chloride yields η⁵-C₅H₅(CO)₂FeCH₂C₆H₅ as the only isolated product.     

Carbonyl rhodium(I) complexes with α-diimines ligands

The reactions of [Rh(CO)₂Cl]₂ with α-diimines, RN=CR′-CR′=NR (R = c-Hex, C₆H₅, p-C₆H₄OH, p-C₆H₄CH₃, p-C₆H₄OCH₃, R′ = H; R = c-Hex, C₆H₅, p-C₆H₄OH, p-C₆H₄OCH₃; R′ = Me) in 2:1 Rh/R-dim ratio gave rise to ionic compounds [(CO)₂Rh.R-dim(R′,R′)][Rh(CO)₂Cl₂] which have been characterized by elemental analyses, electrical conductivity, ¹H-NMR and electronic and IR spectroscopy. Some of these complexes must involve some kind of metal-metal interaction. The complex [Rh(CO)₂Cl.c-Hex-dim(H,H)] has been obtained by reaction of [Rh(CO)₂Cl]₂ with the c-Hex-dim(H,H) ligand in 1:1 Rh/R-dim ratio. The reactions between [(CO)₂Rh.R-dim(H,H)][Rh(CO)₂Cl₂](R = c-Hex or p-C₆H₄OCH₃) with the dppe ligand have been studied. The known complex RhCl(CO)(PPh₃)₂ has been isolated from the reaction of [(CO)₂Rh.R-dim(H,H)]-[Rh(CO)₂Cl₂] (R = c-Hex or p-C₆H₄OCH₃) with PPh₃ ligand.     

Mechanism of the thermal decomposition of (η5-C5H5)Fe(CO)2(η1-acenaphthenyl)

The complexes (η⁵-C₅H₅)Fe(CO)₂(η¹-acenaphthenyl) (I), (η⁵-C₅H₅)Fe(CO)₂ (η¹-trans-β-deuterioacenaphthenyl) (II), and (η-C₅D₅)Fe(CO)₂, (η¹-acenaphthenyl) (XIII) have been prepared and their thermal decomposition studied in vacuo and in refluxing toluene. All three complexes decompose to produce mixtures of acenaphthene (VII), acenaphthylene (VIII), and [C₅H₅Fe(CO)₂]₂ (VI). Biacenaphthenyl (IX) is also obtained from the thermolysis of I in toluene. The formation of alkene VIII, and, to a lesser extent, alkane VII is suppressed by external CO. Thermolysis of I in toluene-d₈ and of II in vacuo and in toluene produces deuterium-enriched VII. The acenaphthene generated from the decomposition of XIII also contains deuterium. The above observations are accomodated by a mechanistic scheme involving competing β-elimination, ironcarbon bond homolysis to produce the acenaphthenyl radical, and CpH abstraction by an undetermined pathway.     

Metal dimers as catalysts : III. The reaction between Fe(CO)5, and group V donor ligands in the presence of [(η5-C5H4R)Fe(CO)222]2 (R  H,Me) and [(η5-C5Me5)Fe(CO)2]2 as catalyst

The reaction between Fe(CO)₅, and group V donor ligands L, (L  PPh₃, AsPh₃, SbPh₃, PMePh₂, PMe₂Ph, Asme₂Ph, P(C₆H₁₁)₃, P(n-Bu)₃, P(i-Bu)₃, P(OPh)₃, P(OEt)₃, P(OMe)₃) in the presence of [(η⁵-C₅Me₅Fe(CO)₂]₂ (R  H, Me) or [(η⁵-C₅Me₅)Fe(CO)₂]₂ as catalyst in refluxing toluene, rapidly gives the complexes Fe(CO)₄L in yields > 85%. The reaction rate is essentially independent of the nature of L for [(η₅-C₅Me₅)Fe(CO)₂]₂ as catalyst. For the other catalysts, the rate is influenced predominantly by the steric properties of L. These results are interpreted in terms of the interaction between the catalyst and the ligand L to give derivatives of the type (η⁵-C₅H₄R)₂Fe₂,(CO)₃,(L). These derivatives were also found to catalyse the reaction between Fe(CO)₅, and L. The complexes [(η-C₅H₄R)Fe(CO)₂]₂ (R  H, Me) and [(η⁵-C₅Me₅)Fe(CO)₂]₂ also catalyse the reaction between Mn₂(CO)₁₀ and PPh₃ to give Mn₂(CO)₈- PPh₃)₂ in > 80% yield.     

Übergangsmetallcarbin-komplexe: LXXXV. Strukturuntersuchungen der reaktionsprodukte von trans-Br(CO)2L2LCNEt2 (L2 = 2,2′-bipyridyl, 1,10-phenanthrolin) mit den organylanionen [(CO)5MEPh2]− (M = Cr,Mo, W; E = P,As, Sb)

The reaction of trans-Br(CO)₂L₂WCNEt₂ (L₂ = 2,2′-bipyridyl (2,2′-bipy), 1,10-phenanthroline (ophen)) with organyl anions of Main Group V elements coordinated to a pentacarbonylmetal fragment of the general formula [(CO)₅MEPh₂]⁻ (M = Cr, Mo, W; E = P, As, Sb) leads, by substitution of the bromine ligand, to new neutral diethylaminocarbyne complexes of the type (CO)₅MEPh₂(CO)₂L₂-WCNEt₂ (M = Cr, Mo, W; E = P, As, Sb; L₂ = 2,2′-bipy, ophen) which contain a heavier element of Main Group V in a bridging position between two transition metals. Spectroscopic investigations at low temperatures show that the bridged complexes exist as a mixture of cis and trans isomers, with the thermodynamic equilibrium favouring the cis complexes. Temperature dependent NMR spectra indicate a dynamic process in which the chelating ligand L₂ (L₂ = 2,2′-bipy, ophen) switches between two cis and two cis / trans positions, relative to the carbyne ligand, and causes a rapid interconversion of the two stereoisomers at room temperature.     

Structure and bonding in haloarylgallyl complexes of iron, ruthenium and osmium [(η-C5H5)(CO)2M{Ga(X)(Ph)}]: A theoretical study

Density Functional Theory calculations have been performed for the halophenylgallyl complexes of iron, ruthenium and osmium [(η⁵-C₅H₅)(CO)₂M(Ga(X)Ph)] (M = Fe, Ru, Os; X = Cl, Br, I) at the DFT/BP86/TZ2P/ZORA level of theory. The calculated geometry of iron complexes [(η⁵-C₅H₅)(CO)₂Fe(Ga(Cl)Ph)] and [(η⁵-C₅H₅)(CO)₂Fe(Ga(I)Ph)] is in excellent agreement with structurally characterized complexes [(η⁵-C₅H₅)(CO)₂Fe(Ga(Mes^∗)Cl)], [(η⁵-C₅Me₅)(CO)₂Fe(Ga(Mes^∗)Cl)] and [(η⁵-C₅Me₅)(CO)₂Fe(Ga(Mes)I)] (Mes = C₆H₂Me₃-2,4,6; Mes^∗ = C₆H₂^tBu₃-2,4,6). The M-Ga bond distances as well as Mayer bond order of the M-Ga bonds suggest that the M-Ga bonds in these complexes are nearly M-Ga single bond. The π-bonding component of the total orbital contribution is significantly smaller than that of σ-bonding. Thus, in these complexes the Ga(X)Ph ligand behaves predominantly as a σ-donor. The contributions of the electrostatic interaction terms ΔE_elstat are significantly smaller in all gallyl complexes than the covalent bonding ΔE_orb term. The absolute values of the ΔE_Pauli, ΔE_int and ΔE_elstat contributions to the M-Ga bonds increase in both sets of complexes via the order Fe < Ru < Os. In the complexes [(η⁵-C₅H₅)(Me₃P)₂Fe(Ga(X)Ph)] (X = Cl, Br, I), interaction energy as well as bond dissociation energy decrease upon going from X = Cl to X = I.     

Heterometallische Clusterkomplexe der Typen Re2(μ-PR2)(CO)8(HgY) und ReMo(μ-PR2)(η5-C5H5)(CO)6(HgY) (R = Ph,Cy; Y = Cl,W(η5-C5H5)(CO)3)

Heterometallic Cluster Complexes of the Types Re₂(μ-PR₂)(CO)₈(HgY) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgY) (R = Ph, Cy; Y = Cl, W(η⁵-C₅H₅)(CO)₃) Dinuclear complexes Re₂(μ-H)(μ-PR₂)(CO)₈ and ReMo(μ-H)(μ-PR₂)(η⁵-C₅H₅)(CO)₆ (R = phenyl, cyclohexyl) were deprotonated and reacted as anions with HgCl₂ to compounds of the both types Re₂(μ-PR₂)(CO)₈HgCl) and ReMo(μ-PR₂)(η⁵-C₅H₅)(CO)₆(HgCl). The heterometallic three-membered cluster complexes correspond to an isolobal exchange of a proton against a cationic HgCl⁺ group. For one of the products ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) has been shown its conversion with NaW(η⁵-C₅H₅)(CO)₃ to ReMo(μ-PCy₂)(η⁵-C₅H₅)(HgW(η⁵-C₅H₅)(CO)₃) under substitution of the chloro ligand, par example. The newly prepared compounds were characterized by means of IR, UV/VIS and ³¹P NMR data. A complete determination of the molecular structure by single crystal analyses was done in the case of Re₂(μ-PCy₂)(CO)₈(HgCl) and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgCl) which both are dimer because of the presence of an asymmetric dichloro bridge, and of ReMo(μ-PCy₂)(η⁵-C₅H₅)(CO)₆(HgW(η⁵-C₅H₅)(CO)₃). The structural study illustrates through comparison the influence of various metal types on an interaction between centric and edge-bridged frontier orbitals in three-membered metal rings.     

Structural characterization of the anionic halfsandwich complex [Li(TMEDA)2][Mo(η5-C5H5)(CO)3] and its reactivity towards stannanes and distannanes

The crystal structure of the molybdenum half sandwich alkali salt [Li(TMEDA)₂][Mo(η⁵-C₅H₅)(CO)₃] shows the occurrence of a separated ion pair in the solid state. Furthermore, the crystal structures of the long known organotin complexes [Mo(η⁵-C₅H₅)(SnMe₃)(CO)₃], [{Mo(η⁵-C₅H₅)(CO)₃}₂SnMe₂] and [Mo(η⁵-C₅H₅)(SnMeCl₂)(CO)₃] have been recorded. The chlorination of [Mo(η⁵-C₅H₅)(SnMe₃)(CO)₃] with SnCl₄ is presented as an improved synthetic access to [Mo(η⁵-C₅H₅)(SnMeCl₂)(CO)₃]. Finally, the reaction of Li[Mo(η⁵-C₅H₅)(CO)₃] with ^tBu₂(Cl)Sn–Sn(Cl)^tBu₂ leads to the novel molybdenum distannane complex [Mo(η⁵-C₅H₅){Sn^tBu₂-Sn(Cl)^tBu₂}(CO)₃], which is fully characterized by NMR, elemental and X-ray analysis.     

Übergangsmetall-substituierte acylphosphane und phosphaalkene: XI. Phosphaalkenyl-, disilylphosphido- und diacylphosphidokomplexe des dicarbonylpentamethylcyclopentadienylosmium. Zur kenntnis von [(η5-C5Me5)Os(CO)2]2

The reaction of Os₃(CO)₁₂ with C₅Me₅H in boiling decalin gives the complexes (η⁵-C₅Me₅)(CO)₂OsH and [(η⁵-C₅Me₅)(CO)₂Os]₂. Both compounds were converted into (η⁵-C₅Me₅)(CO)₂OsP(SiMe₃)₂ (III) via the intermediate form (η⁵-C₅-Me₅)(CO)₂OsBr. Complex III was treated with ArC(O)Cl (Ar = Ph, 2,4,6-Me₃C₆H₂) to give mixtures of the phosphaalkenyl complexes (η⁵-C₅Me₅)(CO)₂OsPC(OSiMe₃)(Ar) (IVa, b) and the diacylphosphido complexes (η⁵-C₅Me₅)(CO)₂-OsP[C(O)Ar]₂ (Va, b). Pivaloyl chloride underwent reaction with III to give complex Vc as the only product. The synthesis of the complexes IVa, b includes an E/Z isomerization process.