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Hydrolysis of the vinylidene complex [Ru(η5-C5H5){=C=C(H)Ph} (PPh3){P(OMe)3}]BPh4 afforded the mixed-ligands carbonyl derivative [Ru(η5-C5H5)(CO)(PPh3){P(OMe)3}]BPh4. Its structure has been determined by X-ray diffraction. The compound crystallizes in the monoclinic crystal system, space group P21/c, with one anion and one cation in the asymmetric unit. The cation complex contains a ruthenium atom in a half-sandwich piano-stool structure. One trimethylphosphito, one triphenylphosphine and one carbonyl ligand are the legs of the stool. [ABSTRACT FROM AUTHOR]

Hydrolysis of the vinylidene complex [Ru(η5-C5H5){=C=C(H)Ph} (PPh3){P(OMe)3}]BPh4 afforded the mixed-ligands carbonyl derivative [Ru(η5-C5H5)(CO)(PPh3){P(OMe)3}]BPh4. Its structure has been determined by X-ray diffraction. The compound crystallizes in the monoclinic crystal system, space group P21/c, with one anion and one cation in the asymmetric unit. The cation complex contains a ruthenium atom in a half-sandwich piano-stool structure. One trimethylphosphito, one triphenylphosphine and one carbonyl ligand are the legs of the stool. [ABSTRACT FROM AUTHOR]

The novel heterobinuclear μ-vinylidene complex [Cp(CO) 2 Re(μ-C=CHPh)Pt(PPh 3 )(CO)] ( 1 ) was isolated from the reaction mixture of [Cp(CO) 2 Re(μ-C=CHPh)Fe(CO) 4 ] and Pt(PPh 3 ) 4 for the first time. Alternative high-yield synthetic approaches to 1 were developed including the reactions of [Cp(CO) 2 Re(μ-C=CHPh)Pt(PPh 3 ) 2 ] ( 2 ) with Co 2 (CO) 8 and Rh(acac)(CO) 2 . The complex was characterized by IR and 1 H, 13 C and 31 P NMR spectroscopy, a molecular structure of 1 was determined by X-ray diffraction analysis. The electrochemical behavior of the new complex was studied by cyclic voltammetry at platinum or glassed carbon electrodes and by dc polarography at a dropping mercury electrode. [ABSTRACT FROM AUTHOR]

The gold acetylide complex 20 endowed with a biaryl backbone provides opportunities for a study on the formation and fate of gold vinylidenes. Although the formyl group in 20 is not sufficiently electrophilic to get attacked by the acetylide in proximity, its activation with TBSOTf (TBSOTf= tert-butyldimethylsilyl trifluoromethanesulfonate) at low temperature triggered instantaneous formation of a gold vinylidene ( 21). This metastable species evolved into the cationic gold carbene complex 22 bearing a phenanthrene unit and a hydroxyl group at the aurated center; the recorded data suggest that this product might be better viewed as an acylgold species protonated by triflic acid. The use of [Me3O⋅BF4] as the activating agent led to formation of the analogous Fischer-type carbene 24, whereas replacement of gold by the [CpRu(PPh3)2]+ fragment allowed the ruthenium vinylidene 27 to be isolated, which closely resembles the proposed gold intermediate 21. The starting gold complex 20, the derived products 22 and 24, as well as vinylidene 27 were characterized by X-ray diffraction. [ABSTRACT FROM AUTHOR]

This is a review of papers published in the year 2014 that focus on the synthesis, reactivity, or properties of compounds containing a carbon-transition metal double or triple bond. [ABSTRACT FROM AUTHOR]

Structures and relative energies of binuclear iron-manganese complexes with the phosphine ligand L, which exist in vinylidene Cp(CO)(L)MnFe(μ-C=CHPh)(CO) ( 2) and benzylidene ketene η-{C[Mn(CO)(L)Cp]∙ ∙(CO)CHPh}Fe(CO) ( 3) forms are calculated by the B3LYP density functional method. Four isomers with different positions of ligand L relative to the phenyl ring (conformers a and b) and the substituent Ph relative to the С=С bond (conformers E and Z) are considered for each form and their relative stability is determined. It is shown that all isomers of 2 have approximately the same energy (within 4 kcal/mol) whereas the energies of isomers of 3 differ within 21 kcal/mol. Isomer 3Ea in which the PPh ligand contacts with the phenyl substituent of the vinylidene group is most energetically favorable. It is found that with an increase in the L ligand size in the order PH < PHPh < PHPh < PPh the Mn-P bond length increases to 2.37 Å in the most stable isomer of form 3 and to 2.43 Å in the isomers of 2 and three conformers of 3. A more substantial increase in the Mn-P bond length in complexes 2 and 3 correlates with their lower stability as compared to isomer Ea of 3, which is consistent with experimental data on the presence of only one conformer 3Ea in solution. [ABSTRACT FROM AUTHOR]

The novel tetranuclear di-vinylidene complex Cp 2 (CO) 4 RePd(μ 2 -C CHPh)RePd(μ 3 -C CHPh)(dppe) was isolated and characterized by X-ray diffraction. This cluster consists of two RePd fragments linked to each other through the bonding of the palladium atom in the [Cp(CO) 2 RePd(μ-C CHPh)] fragment to the carbonyl and vinylidene ligands in the Cp(CO) 2 RePd(μ-C CHPh)(dppe) fragment. [ABSTRACT FROM AUTHOR]

The single crystal X-ray diffraction study of the heterometallic cluster CpMnFePt(μ-C=CHPh)(PPh)(CO) is performed. The crystallographic characteristics are as follows: a = 32.356(15) Å, b = 11.754(5) Å, c = 20.114(9) Å, β = 115.707(6)°, V = 6893(5) Å, space group C2/ c, Z = 8, d = 1.741 g/cm. The cluster molecule contains a bridging phenylvinylidene ligand coordinated to a metallic core in the form of a Mn-Fe-Pt chain (the Mn-Fe and Fe-Pt bond lengths are 2.6768(14) Å and 2.6280(11) Å respectively and the Mn⋯Pt distance is 3.6425(19) Å). [ABSTRACT FROM AUTHOR]

The reaction of [Cp(CO) 2 Re C CHPh] ( 1 ) with [Pd(PPh 3 ) 4 ] followed by the treatment of resulting [Cp(CO) 2 RePd(μ-C CHPh)(PPh 3 ) 2 ] ( 2 ) with diphosphines (dppe, dppp) gave new complexes [Cp(CO) 2 RePd(μ-C CHPh)(dppe)] ( 3 ) and [Cp(CO) 2 RePd(μ-C CHPh)(dppp)] ( 4 ). Treatment of the synthesized complexes with [Fe 2 (CO) 9 ] led to mixtures of [Cp(CO) 2 ReFe(μ-C CHPh)(CO) 4 ] ( 5 ), [(dppe)PdFe 2 (CO) 8 ] ( 6 ), [CpReFe 2 (μ 3 -C CHPh)(CO) 8 ] ( 7 ), [CpReFePd(μ 3 -C CHPh)(CO) 5 (dppe)] ( 8 ) and of 5 , [(dppp)PdFe 2 (CO) 8 ] ( 9 ), [CpReFePd(μ 3 -C CHPh)(CO) 5 (dppp)] ( 10 ), respectively. The main products of both reactions were trinuclear μ 3 -vinylidene clusters 8 and 10 . Reactions of the trinuclear μ 3 -vinylidene ReFePd clusters 8 and 10 with Fe 2 (CO) 9 were also studied. New complexes were characterized by IR, 1 H, 13 C, 31 P NMR spectroscopy and cyclic voltammetry. The structure of [CpReFe 2 (μ 3 -C CHPh)(CO) 8 ] was determined by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Abstract: The interaction between Cp(CO)2Re C CHPh (1) and CuCl results in the new heterometallic μ-vinylidene complex [Cp(CO)2ReCu(μ2-C CHPh)(μ2-Cl)]2 (2) characterized earlier by IR and 1H, 13C NMR spectra. The molecular structure of compound 2 has been determined by X-ray diffraction analysis, revealing a dimer structure with two binuclear fragments linked to each other by asymmetric chloride bridges. The electrochemical behavior of 2 in acetonitrile was studied by cyclic voltammetry at a Pt-electrode. [Copyright &y& Elsevier]

Reaction of Cp(CO)2Re=C=CHPh (1) with Pt(PPh3)4 and subsequent treatment of Cp(CO)2RePt(μ–C=CHPh)(PPh3)2 (2) with diphosphines P–P = dppe, dppp afforded new complexes Cp(CO)2RePt(μ–CCHPh)(P–P) (4, 5). The structures of Cp(CO)2RePt(μ–C=CHPh)(dppp) (5) and Cp(CO)2MnPt(μ–C=CHPh)(dppp) (10) have been determined by single crystal XRD. The influence of the nature of M = Re, Mn and L2 = (PPh3)2, dppm, dppe, dppp at the Pt atom on the structural, IR and 1H, 13C and 31P NMR spectroscopic characteristics of complexes Cp(CO)2MPt(μ–C=CHPh)(L2) (2–5, 7–10) is considered. [ABSTRACT FROM AUTHOR]

The labile iridium(I) precursor trans-[IrCl(C8H14)(PiPr3)2] (2), prepared in situ from [IrCl(C8H14)2]2 (1) and PiPr3, reacted with equimolar amounts of 1,4-C6H4(C≡CSiMe3)2 (3) at 60°C to give the mononuclear vinylidene complex trans-[IrCl(=C=C(SiMe3)C6H4C≡CSiMe3)(PiPr3)2] (4). From 2 and 3 in the molar ratio of 2:1, the dinuclear compound trans,trans-[(PiPr3)2ClIr(=C=C(SiMe3)C6H4C(SiMe3)=C=)IrCl(PiPr3)2] (5) was obtained. Reaction of 4 with [RhCl(PiPr3)2]2 (6) at room temperature afforded the heterodinuclear alkyne(vinylidene) complex trans,trans-[(PiPr3)2ClIr(=C=C(SiMe3)C6H4C≡CSiMe3)RhCl(PiPr3)2] (7), which on heating at 45 °C was converted to the bis(vinylidene) isomer trans,trans-[(PiPr3)2ClIr(=C=C(SiMe3)C6H4C(SiMe3)=C=)RhCl(PiPr3)2] (8). [ABSTRACT FROM AUTHOR]

Abstract: This is a review of papers published in the year 2009 that focus on the synthesis, reactivity, or properties of compounds containing a carbon-transition metal double or triple bond. [ABSTRACT FROM AUTHOR]

Abstract: Monomeric ruthenium(0) complexes containing redox-coupled dienone ligands were found to catalyze the regio-selective addition of carboxylic acids or cyclic 1,3-dicarbonyl compounds to propargyl alcohols. [Copyright &y& Elsevier]

Abstract: This is a review of papers published in the year 2008 that focus on the synthesis, reactivity, or properties of compounds containing a carbon-transition metal double or triple bond. [Copyright &y& Elsevier]

Abstract: This is a review of papers published in the year 2007 that focus on the synthesis, reactivity, or properties of compounds containing a carbon-transition metal double or triple bond. [Copyright &y& Elsevier]

The reactions of Cp(CO)2Re=C=CHPh ( 2) with M(PPh3)4 (M = Pd, Pt) gave the μ-vinylidene complexes Cp(CO)2RePd(μ-C=CHPh)(PPh3)2 ( 3) and Cp(CO)2RePt(μ-C=CHPh)(PPh3)2 ( 1), respectively. The substitution of Ph2PCH2PPh2 (dppm) for the PPh3 ligands in 1 resulted in the formation of Cp(CO)RePt(μ-C(1)=C(2)HPh)(μ-CO)(dppm) ( 4). The structure of complex 4 has been determined by single-crystal X-ray diffraction analysis. The structural and spectroscopic characteristics of complexes 1, 3, and 4 were compared with the corresponding parameters of the manganese-containing analogs Cp(CO)2MnPd(μ-C=CHPh)(PPh3)2 ( 5), Cp(CO)2MnPt(μ-C=CHPh)(PPh3)2 ( 6) and Cp(CO)2MnPt(μ-C=CHPh)(dppm) ( 7). [ABSTRACT FROM AUTHOR]

Abstract: The interaction between Cp(CO)2RePt(μ-C3)2 (1) and Fe2(CO)9 afforded the new heterometallic μ3-vinylidene cluster CpReFePt(μ3-C6(PPh3) (2). An X-ray diffraction study shows the complex 2 possesses a trimetallic Re–Fe–Pt chain core. The bond lengths are Re–Fe 2.8221(8), Fe–Pt 2.5813(8)Å; the Re⋯Pt distance is 3.3523(7)Å; the bond angle Re–Fe–Pt is 76.55(3)°. The μ3-Cnd is η1-bound to the Re and Pt atoms and η2-coordinated to the Fe atom. The Cngth is 1.412(4)Å. The Pt atom is coordinated by the PPh3 and CO groups. Complex 2 is characterized by the IR and 1H, 13C and 31P NMR spectra. [Copyright &y& Elsevier]

Abstract: The 2-His-1-carboxylate triad is a common metal binding motif in non-heme iron oxygenases and zinc proteases such as the gluzincins. Tripodal N,N,O-ligands allow to mimic this binding motif in coordination chemistry. Here, we report on a library of achiral, chiral and enantiopure heteroscorpionate ligands including several bis(pyrazol-1-yl)acetic acids and 3,3-bis(imidazol-2-yl)propionic acid. Model complexes thereof with zinc as well as ferrous and ferric complexes will be presented. We will further report on ruthenium(II) model complexes for 2-oxoglutarate dependent enzymes and/or 4-HPPD. Organometallic compounds such as zinc alkyl complexes or ruthenium cumulenylidene complexes bearing these heteroscorpionate ligands have also been obtained. Finally, as a first step towards artificial enzymes, various N,N,O-ligands bearing linker groups suitable for solid phase fixation or copolymerisation will also be discussed. [Copyright &y& Elsevier]

The present paper reports the unprecedented observation of a catalytic electrochemical proton reduction based on metallocumulene complexes. Manganese phenylvinylidene (η5-C5H5)(CO)(PPh3)Mn＝C＝C(H)Ph (1) and diphenylallenylidene (η5-C5H5)(CO)2Mn＝C＝C＝CPh2 (3) are shown to catalyze the reduction of protons from HBF4 into dihydrogen in CH2Cl2 or CH3CN media at −1.60 and −0.84 V (in CH3CN) vs. Fc, respectively. The working potential for 3 (−0.84 V vs. Fc in CH3CN) is the lowest reported to date for protonic acids reduction in non-aqueous media. The similar catalytic cycles disclosed here include the protonation of 1, 3 into the carbyne cations [(η5-C5H5)(CO)(PPh3)Mn≡C–CH2Ph]BF4 ([2]BF4), [(η5-C5H5)(CO)2Mn≡C–CH＝CPh2]BF4 ([4]BF4) followed by their reduction to the corresponding 19-electron radicals 2˙, 4˙, respectively. Both carbyne radicals undergo a rapid homolytic cleavage of the Cβ–H bond generating an H-radical producing molecular hydrogen with concomitant recovery of the neutral metallocumulenes thereby completing a catalytic cycle. [Copyright &y& Elsevier]

Abstract: The present review summarizes the syntheses, structures, physicochemical properties and reactivity of complexes containing η1-, μ-, μ3- and μ4-vinylidene ligands. Consideration of mononuclear vinylidene complexes is limited to cymantrene derivatives, one of which, viz. Cp(CO)2Mnh name="dbnd" />CHPh (1), has served as the precursor for syntheses of many organometallic and some organic compounds. The reactions between phosphites P(OR)3 and complex 1 afford styrylphosphonates PhCH)2. All the transformations of complex 1 occur under very mild conditions. Special attention is paid to heterometallic complexes, containing Mn, Fe and the platinum Group metals with bridging vinylidene ligands. The Mnh name="dbnd" />CHR system is used as a “building block” for a series of dimetal μ-vinylidene complexes including MnM=Mo, W, Mn, Re, Fe, Rh, Pd, Pt, Cu) and trimetallic MnFePt μ3-vinylidene clusters. Transmetalation reactions of the MnPd and MnPt complexes have given a series of μ4-vinylidene PdFe3 and PtFe3 clusters. Transfer of vinylidene from the Mn atom to another metal atom (Re), to the dinuclear (FePt) and cluster (Os3, PdFe3, PtFe3) systems has been shown. A systematic study of a dependence of structural and spectroscopic parameters of mono-, di-, tri- and tetra-nuclear complexes on the vinylidene coordination mode has been carried out. [Copyright &y& Elsevier]

Abstract: The crystal and molecular structure of the novel tetranuclear complex (η2-dppe)PdMn(μ3-C(μ-C4Cp2 (5) has been investigated. The metal core of 5 is a bent chain Pd(2)–Mn(2)–Pd(1)–Mn(1). The bond distances and angles are Mn(1)–Pd(1) 2.6025(6), Pd(1)–Mn(2) 2.8913(5), Mn(2)–Pd(2) 2.6463(4)Å, Mn(1)–Pd(1)–Mn(2) 140.2(2)°, Pd(1)–Mn(2)–Pd(2) 69.6(1)°. Complex contains two bridging vinylidene ligands coordinated to metal atoms in different ways. The Cngths are 1.347(4) and 1.372(4)Å in the μ2(η1,η1)-Cμ3(η1,η1,η2)-Cnds, respectively. The η2-dppe ligand is coordinated to the Pd(2) atom to form the chelate cycle. Each of Mn(1) and Mn(2) atoms is bonded with the η5-C5H5 ring and two CO groups. [Copyright &y& Elsevier]

The iridium dinitrogen complex [IrCl(N2)(PPh3)2] (1) was found to react with alkynylsilanes RC≡CSiR'3 to form the vinylidene iridium(I) complexes trans-[IrCl{=C=CR(SiR'3)} (PPh3)2 (R/R′=Ph/Me, 2; Me/Me, 3; Bn/Me, 4; SiMe3/Me, 5; SiEt3/Et, 6; iPr/Me, 7) and with Me3SiC≡CC(O)R to yield the iridium η2-alkyne complexes trans-[IrCl{η2-Me3SiC≡CC(O)R}(PPh3)2] (R=OEt, 9; Me, 11). Complex 9 was found to isomerize upon heating or upon UV irradiation yielding the vinylidene complex trans-[IrCl{=C=C(SiMe3)CO2Et}(PPh3)2] (10). The reaction of 1 with Me3SiC≡C—C≡CSiMe3 yielded the complex trans-[IrCl{=C=C(SiMe3)C≡CSiMe3}(PPh3)2] (8), whereas with MeO2CC≡CCO2Me the iridacyclopentadiene complex [Ir{C4(CO2Me)4}Cl(PPh3)2] (13) was formed. The complexes were characterized by means of 1H, 13C and 31P NMR spectroscopy as well as by IR spectroscopy and microanalysis. [Copyright &y& Elsevier]

Abstract: The complex [Cp∗Ru{OCMe2}(CO)(PMeiPr2)][BAr4′](2,Ar4′=3,5-C6H3(CF3)2) reacts with HCCPh at −40 °C in CD2Cl2 furnishing the π-alkyne adduct [Cp∗Ru(η2-HCCPh)(CO)(PMeiPr2)][BAr4′] (3), which rearranges to the vinylidene complex [Cp∗Ruh name="dbnd" />CHPh(CO)(PMeiPr2)][BAr4′] (4a) when the temperature is raised to 25 °C. [Cp∗RuCCHR(CO)(PMeiPr2)][BAr4′] (R=Ph 4a, tBu4b, H 4c) were obtained by reaction of [Cp∗RuCl(CO)(PMeiPr2)] (1) with NaBAr4′ and alkyne in fluorobenzene. Addition of water to the vinylidene complexes leads to the dicarbonyl [Cp∗Ru(CO)2(PMeiPr2)][BAr4′] (5), whereas deprotonation yields neutral σ-alkynyl complexes [Cp∗Ru(CCR)(CO)(PMeiPr2)] (R=tBu 6b, H 6c). The allenylidene complex [Cp∗Ruh name="dbnd" />CPMeiPr2)][BAr4′] (7) was prepared by reaction of 1 with HCCC(OH)Ph2 and NaBAr4′ in fluorobenzene. [Copyright &y& Elsevier]

Density functional molecular orbital calculations at the BP86 level were performed to investigate rotational barrier of vinylidene ligand in the model complexes OsHCl(CCH2)(L)2 (L=PMe3, PH3, PF3). Results of calculations indicate that the rotational barrier increases with the increasing π-accepting ability of phosphine. This result has been explained on the basis of the extent of π-interaction between metal and vinylidene ligand in the complexes. [Copyright &y& Elsevier]

Four-coordinate rhodium(I) complexes of the general composition trans-[Rh(R)(&z.dbnd6;C&z.dbnd6;CHR′)(PiPr3)2] and trans-[Rh(R)(&z.dbnd6;C&z.dbnd6;CMe2)(PiPr3)2], where R is an alkynyl, aryl, methyl or vinyl group, were prepared by substitution of the chlororhodium(I) precursors trans-[RhCl(&z.dbnd6;C&z.dbnd6;CHR′)-(PiPr3)2] or trans-[RhCl(&z.dbnd6;C&z.dbnd6;CMe2)(PiPr3)2] and a Grignard reagent. The alkynyl derivatives trans-[Rh(C&z.tbnd6;CR)(&z.dbnd6;C&z.dbnd6;CHR)(PiPr3)2] are also accessible from [Rh(η3-CH2Ph)(PiPr3)2] and two equivalents of a terminal alkyne. The reaction of trans-[Rh(R)(&z.dbnd6;C&z.dbnd6;CHR′)(PiPr3)2] and trans-[Rh(Ph)(&z.dbnd6;C&z.dbnd6;CMe2)(PiPr3)2] with CO led to a migration of the alkynyl, aryl, methyl or vinyl group to the α-carbon atom of the vinylidene ligand and gave the η1-vinyl-, η1-butadienyl- and η1-enynylrhodiumcarbonyl complexes trans-[Rh{η1-C(R)&z.dbnd6;CHR′}(CO)(PiPr3)2] in good to excellent yields. The (Z) isomers are preferentially formed. Even in the absence of CO, the methyl and vinyl compounds trans-[Rh(R)(&z.dbnd6;C&z.dbnd6;CHR′)(PiPr3)2] (R = CH3, CH&z.dbnd6;CH2) undergo an intramolecular C&z.sbnd;C coupling reaction to give the η3-allyl and η3-butadienyl isomers [Rh(η3-1-CH2CHCHR′)(PiPr3)2] and [Rh(η3-trans-CH2CHC&z.dbnd6;CHR′)(PiPr3)2]. Acid-induced cleavage of the Rh&z.sbnd;C σ-bond of trans-[Rh{η1-C(R)&z.dbnd6;CHR′}(CO)(PiPr3)2] with acetic acid affords trans-[Rh(κ1-O2CCH3)(CO)(PiPr3)2] and the corresponding olefin or diene, respectively. In contrast, the enynyl complexes trans-[Rh{η1-C(C&z.tbnd6;CR)&z.dbnd6;CHR′}(CO)(PiPr3)2] (R = R′ = Ph, tBu) react with CF3CO2H to give almost exclusively the butatrienes RCH&z.dbnd6;C&z.dbnd6;C&z.dbnd6;CHR′. Treatment of [Rh(η3-1-CH2CHCHR′)(PiPr3)2] and [Rh(η3-trans-CH2CHC&z.dbnd6;CHR′)(PiPr3)2] with acid gives [Rh(κ2-O2CCH3)(PiPr3)2] and the respective olefin or diene. With the chelate compound [Rh(κ2-O2CCH3)(PiPr3)2] as the starting material, a stepwise trimerization of HC&z.tbnd6;CCO2Me can be performed which, however, does not lead to a trisubstituted arene but selectively to a hexadienyne derivative. The C4-bridged vinylidenerhodium(I) complexes trans-[{Rh(&z.dbnd6;C&z.dbnd6;CHR)(PiPr3)2}2(μ-C&z.tbnd6;C-C&z.tbnd6;C)] react with CO and 2,6-dimethylphenylisocyanide by a twofold migratory insertion to give the dinuclear compounds trans-[{Rh(CX)(PiPr3)2}2{μ-C(&z.dbnd6;CHR)C&z.tbnd6;C-C&z.tbnd6;C(&z.dbnd6;CHR)}], which contain a highly unsaturated eight-membered C8 chain as the bridge. [Copyright &y& Elsevier]

The present review reports on the chemistry and catalytic applications of Group 8 half-sandwich complexes containing non-heteroatom stabilized α,β-unsaturated alkylidene and cumulenylidene groups. These include bis-carbenes , mono- and polyhapto alkenyl-alkylidenes [MLn]&z.dbnd6;C(R1)&z.sbnd;C(R2)&z.dbnd6;CR3(R4), as well as substituted vinylidene [MLn]&z.dbnd6;C&z.dbnd6;CR1(R2) and allenylidene [MLn]&z.dbnd6;C&z.dbnd6;C&z.dbnd6;CR1(R2) complexes (R1 and/or R2 = unsaturated hydrocarbon substituent). Synthetic methodologies and stoichiometric reactions as well as the involvement of these species in a series of catalytic transformations are presented. Important recent developments in catalytic studies reveal the role of bis-carbene and alkenyl–vinylidene species as intermediate active species in C&z.sbnd;C coupling reactions of alkynes. [Copyright &y& Elsevier]

The nonlinear optical (NLO) properties of metal acetylide and vinylidene complexes are summarized, and molecular structure–NLO property trends are developed. The origin of NLO effects in molecules is presented, and the advantages and shortcomings of experimental procedures that have been used to measure optical nonlinearities for these complexes are discussed. Attempts to “switch” optical nonlinearities of acetylide or vinylidene complexes are summarized. [Copyright &y& Elsevier]

The reaction of [Rh{κ2-O2S(O)CF3}(PiPr3)2] (1) with ethynylferrocene in the presence of KF affords the substituted vinylidene complex trans-[RhF{&z.dbnd6;C&z.dbnd6;CH(C5H4)Fe(C5H5)}(PiPr3)2] (2) which upon treatment with the butadiyne derivative Ph3SnC&z.tbnd6;C&z.sbnd;C&z.tbnd6;CSnPh3 produces the chain-like compound trans-[(μ-C&z.tbnd6;C&z.sbnd;C&z.tbnd6;C){Rh(&z.dbnd6;C&z.dbnd6;CH(C5H4)Fe(C5H5))(PiPr3)2}2] (7). The triflato complex 1 reacts with 1,4-C6H4(C&z.tbnd6;CH)2 to give the dinuclear compound trans-[{μ-1,4-C6H4(CH&z.dbnd6;C&z.dbnd6;)2}{Rh(η1-OS(O)2CF3)(PiPr3)2}2] (3) which in the presence of KF undergoes a ligand exchange to give the corresponding difluoro derivative 4. From 4 and RC&z.tbnd6;CSnPh3 (R=CH3, C6H5) the complexes 5 and 6, in which a C6H4 unit bridges two alkynyl(vinylidene)rhodium(I) fragments, are obtained. Both 6 and 7 react with CO by migratory insertion of the vinylidene units into the alkynyl-metal bonds to afford the dinuclear complexes 8 and 9, in which an unusual C8 or C4(C6H4)C4 chain bridges the two rhodium centers. The reactions of [RhCl(PiPr3)2]2 (10) with the functionalized diynes 1,1′,4,4′-C6H4(OH)2(C&z.tbnd6;CH)2 and 1,4-C6H4[C(Ph)(OH)C&z.tbnd6;CH]2 lead, via the corresponding diyne-metal species 11 and 12 as intermediates, to the formation of the bis(vinylidene) complexes 13 and 14, the latter of which reacts with acidic Al2O3 by elimination of water to give the novel phenylene-bridged bis(allenylidenerhodium) compound [{μ-1,4-C6H4(CPh&z.dbnd6;C&z.dbnd6;C&z.dbnd6;)2}{RhCl(PiPr3)2}2] (15) in 80% yield. [Copyright &y& Elsevier]

Thermolysis of the pentacarbonyl(vinylidene)chromium complexes [(CO)5Cr&z.dbnd6;C&z.dbnd6;C(R1)R2] (1a–d) (C(R1)R2=CMe2 (a), C(CH2)5 (b), C(Et)Me (c), C(tBu)Me (d)), affords binuclear, vinylidene-bridged nonacarbonyldichromium complexes, [(CO)5Cr(μ-η1,η2-C&z.dbnd6;C(R1)R2)Cr(CO)4] (2a–d). The solid-state structures of 2a and 2d have been established by X-ray structural analyses. The structural data prove the μ-η1,η2-C&z.dbnd6;C(R1)R2 bonding mode. To account for the NMR spectroscopic features a dynamic process is proposed involving rapid coordination site exchange of the C&z.dbnd6;C bond between Cr(1) and Cr(2) (windshield wiper mechanism) and of one CO ligand. [Copyright &y& Elsevier]

The diphenylallenylidene complex [Ru(&z.dbnd6;C&z.dbnd6;C&z.dbnd6;CPh2)(η5-C9H7)(PPh3)2][PF6] (1) regioselectively reacts at the Cγ atom with the lithium enolate derived from (1R)-(+)-camphor to yield σ-alkynyl derivative [Ru{C&z.tbnd6;CCPh2(C10H15O)}(η5-C9H7)(PPh3)2] (2). Complex 2 was obtained as a non-separable mixture of two diastereoisomers, i.e. (1R,3S,4R)-2 and (1R,3R,4R)-2 (ca. 3:2 ratio), in which the alkynyl fragment is located in exo or endo disposition on the camphor skeleton, respectively. Protonation of this mixture with HBF4·Et2O affords the vinylidene derivative [Ru{&z.dbnd6;C&z.dbnd6;C(H)CPh2(C10H15O)}(η5-C9H7)(PPh3)2][BF4] (3) as a single diastereoisomer, i.e. (1R,3S,4R)-3, showing an exo disposition of the vinylidene group. The structure of complex (1R,3S,4R)-3 has been confirmed by X-ray diffraction. The molecular structure shows the typical pseudo-octahedral three-legged piano-stool geometry around the ruthenium atom, which is linked to the phosphorus atoms of the PPh3 ligands, to the η5-bonded indenyl ligand, and to an almost linear vinylidene chain (Ru&z.sbnd;C(1)&z.sbnd;C(2)=165.6 (18)°) with a Ru&z.sbnd;C(1) bond length of 1.88 (2) A˚. Demetalation of (1R,3S,4R)-3, by treatment with acetonitrile at reflux, yields the terminal alkyne HC&z.tbnd6;CCPh2(C10H15O) (4) and the nitrile complex [Ru(N&z.tbnd6;CMe)(η5-C9H7)(PPh3)2][BF4] (5). Compound 4 was obtained as a non-separable mixture of two diastereoisomers, i.e. (1R,3S,4R)-4 and (1R,3R,4R)-4 (ca. 3:1 ratio). Related reactions starting from diphenylallenylidene 1 and the (1S)-(−)-camphor enolate are also reported. [Copyright &y& Elsevier]

Density functional theory (DFT) calculations were carried out for trans-[RhX(L)(PMe3)2] (L=C&z.dbnd6;CH2, C&z.dbnd6;CHC6H5, CO, 2,6-Me2C6H3NC, C2H4) which served as model compounds for the analysis of the vibrational spectra of related complexes. The characterization of the metal&z.sbnd;carbon stretching mode allowed to study the trans influence of a series of ligands on the metal&z.sbnd;carbon bond in vinylidene, carbonyl and isocyanide complexes. Furthermore, the comparison of the FT-Raman spectra of the complexes trans-[RhF(CO)(PiPr3)2] and trans-[RhF(13C&z.dbnd6;13CH2)(PiPr3)2] which possess the same reduced mass (13C&z.dbnd6;13CH2 vs. CO) allowed for an evaluation of the Rh&z.sbnd;C bond strength free of any mass effects and therefore only showing effects of electronic nature. [Copyright &y& Elsevier]

The reaction of [RhCl(C8H14)2]2 with 4 equiv. of PiPr3 and an equimolar amount of 1,3-C6H4(NC)2 in benzene–ether led to the formation of the dinuclear diisonitrile complex trans-[{RhCl(PiPr3)2}2{μ-1,3-(CN)2C6H4}] (2) in 75% yield. The related iodo compound trans-[{RhI(PiPr3)2}2{μ-1,3-(CN)2C6H4}] (3) was obtained from 2 and NaI by salt metathesis. Density functional theory (DFT) calculations have been carried out for the model complexes trans-[RhX(CNC6H5)(PMe3)2] (X=F, Cl) and trans-[{RhF(PMe3)2}2{μ-1,3-(CN)2C6H4}] in order to assign the vibrational modes of compounds 2 and 3. Moreover, the FT-Raman spectrum of the free ligand m-diisocyanobenzene has been measured and analyzed based on the calculation of the Raman intensities for the normal modes using the BPW91/6-31+G(d) method. The most noteworthy result is that the RhC stretching mode of 2 appears at almost the same wavenumber as that of the vinylidene complex trans-[RhCl(&z.dbnd6;C&z.dbnd6;CHC6H5)(PiPr3)2]. The crystal and molecular structure of 2 has been determined by X-ray crystallography. [Copyright &y& Elsevier]

The chelate complex [RuCl[sub 2] {κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ] (1) reacted, in the presence of CF[sub 3] SO[sub 3] Ag, with 1 equiv of C[sub 6] H[sub 4] (CºCH)[sub 2] -p (4) to afford the mononuclear vinylidene compound [RuCl(C=CHC[sub 6] H[sub 4] -p-CºCH){κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ](CF[sub 3] SO[sub 3] ) (3). From 1 and 0.5 equiv of 4, the binuclear bis(vinylidene) complex [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -p-CH=C)RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ](CF[sub 3] SO[sub 3] )[sub 2] (6) was obtained. The related compound [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m-CH=C)RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ](CF[sub 3] SO[sub 3] )[sub 2] (7) was prepared from 1, 0.5 equiv of C[sub 6] H[sub 4] (CºCH)[sub 2] -m (5), and silver triflate. The reaction of 2 or 3 with [RhCl(P-i-Pr[sub 3] )[sub 2] ][sub 2] (8) in the molar ratio of 2:1 yields, by addition of the 14-electron fragment [RhCl(P-i-Pr[sub 3] )[sub 2] ] to the uncoordinated C—C triple bond, the heterobinuclear complexes [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m/p-CºCH)RhCl(P-i-Pr[sub 3] )[sub 2] ](CF[sub 3] SO[sub 3] ) (9, 10) which slowly rearrange at room temperature to give the bis(vinylidene) isomers [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m/p-CH=C)RhCl(P-i-Pr[sub 3] )[sub 2] ](CF[sub 3] SO[sub 3] ) (11, 12).Key words: ruthenium, rhodium, vinylidene complexes, alkyne complexes, phosphine complexes.En présence de CF[sub 3] SO[sub 3] Ag, le chélate complexe [RuCl[sub 2] {κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ] (1) réagit avec un équivalent de C[sub 6] H[sub 4] (CºC)[sub 2] -p (4) pour conduire à la formation du composé vinylidène mononucléaire [RuCl(C=CHC[sub 6] H[sub 4] -p-CºC){κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ](CF[sub 3] SO[sub 3] )[sub 2] (3). À partir de 1 et d'un demi-équivalent de 4, on obtient le complexe bis(vinylidène) binucléaire [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -p-C=C)RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ] (CF[sub 3] SO[sub 3] )[sub 2] (6). On a préparé le composé apparenté [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m-C=C)RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] ] (CF[sub 3] SO[sub 3] )[sub 2] (7) en faisant réagir le composé 1 un demi-équivalent de C[sub 6] H[sub 4] (CºCH)[sub 2] -m (5) en présence de triflate d'argent. Par le biais d'une addition du fragment à quatorze électrons [RhCl(P-i-Pr[sub 3] )[sub 2] ] à la triple liaison qui n'est pas coordinée, les réactions des composés 2 ou 3 avec le [RhCl(P-i-Pr[sub 3] )[sub 2] ][sub 2] (8), dans un rapport molaire de 2:1, conduisent aux complexes hétérobinucléaires [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m/p-CºC)RhCl(P-i-Pr[sub 3] )[sub 2] ] (CF[sub 3] SO[sub 3] )[sub 2] (9, 10) qui se réarrangement lentement à la température ambiante pour conduire aux isomères bis(vinylidènes) [RuCl{κ[sup 2] (P,O)-i-Pr[sub 2] PCH[sub 2] CH[sub 2] OMe}[sub 2] (C=CHC[sub 6] H[sub 4] -m/p-C=C)RhCl(P-i-Pr[sub 3] )[sub 2] ] (CF[sub 3] SO[sub 3] )[sub 2] (11, 12).Mots clés : ruthénium, rhodium, complexes de vinylidènes, complexes d'alcynes, complexes de phosphines.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The solid-state tautomerization of the hydrido-alkynyl derivatives [ Cp*RuH(C&*C R)-( dippe)][BPh4] (Cp* = C5Me5; R = SiMe3, Ph, H; dippe = 1,2-bis-(diisopropylphosphino)-ethane) to their vinylidene isomers [ Cp*Ru*C*CH R( dippe)][BPh4] was studied by IR spectroscopy. Characteristic isothermic α vs. t curves for each individual rearrangement process were recorded. Their shape, and hence the isomerization mechanism, depends strongly on the nature of the substituent R. The kinetic analysis of the above curves using the Avrami- Erofeev provided some mechanistic information about the isomerization process in the solid. [ABSTRACT FROM AUTHOR]

The reaction of Cp(CO)2Mn=C=CHPh( 1) with Pd(PPh3)4 followed by the replacement of the PPh3 ligands by diphosphines Ph2P(CH2)2PPh2 (dppe) or Ph2P(CH2)3PPh2 (dppp) (where dppe is bis(diphenylphosphino)ethane and dppp is 1,3-bis(diphenylphosphino)propane) afforded the binuclear complexes Cp(CO)2MnPd(μ-C=CHPh)(dppe) ( 2a) and Cp(CO)2MnPd(μ-C=CHPh)(dppp) ( 2b), respectively. The reactions of 2a and 2b with Fe2(CO)9 gave the trinuclear complex CpMnFe2(μ3-C=CHPh(CO)3 ( 3). Competitive transmetallation took the second pathway to yield clusters containing the PdFe3 and PdFe2 cores. Complex 3 was also formed in the thermal reaction of compound 1 with Fe2(CO)9. Complex 3 was studied by IR spectroscopy,1H and13C NMR spectroscopy, mass-spectrometry, and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The X-ray diffraction study of a new heterometallic cluster CpReFePt(μ3-C=CHPh)(CO)[P(OPr)] is performed. The crystallographic characteristics are as follows: a = 11.0275(4) Å, b = 33.0367(12) Å, c = 12.2691(5) Å, β = 98.3660(10)°, V = 4422.2(3) Å, space group P2/ n, Z = 4, d = 1.744 g/cm. The cluster contains the phenylvinylidene ligand coordinated with a trimetallic core in the form of a Re-Fe-Pt chain (the Re-Fe and Fe-Pt bond lengths are 2.794(7) Å and 2.628(1) Å respectively; the Re···Pt distance is 3.354(1) Å). [ABSTRACT FROM AUTHOR]

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• The RePt vinylidene complexes with terminal posphites at the Pt atom were obtained. • Applicability of different synthetic approaches to these complexes was shown. • The redox-properties of the RePt vinylidene complexes were investigated. • The molecular structures of the three complexes were determined by X-ray diffraction. Reactions of Cp(CO) 2 Re C CHPh with Pt[P(OR) 3 ] 4 (R = Pri, Et, Ph) gave binuclear μ-vinylidene complexes Cp(CO) 2 RePt(μ-C CHPh)[P(OR) 3 ] 2. Treatment of the previously synthesized Cp(CO) 2 Re(μ-C CHPh)Pt(PPh 3) 2 with triisopropylphosphite or triethylphosphite resulted in a stepwise substitution of PPh 3 ligands, leading to the disubstituted Cp(CO) 2 RePt(μ-C CHPh)[P(OR) 3 ] 2 and monosubstituted Cp(CO) 2 RePt(μ-C CHPh)[P(OR) 3 ](PPh 3) (R = Pri or Et) species, while no triphenylphosphine ligand substitution in the reaction with P(OPh) 3 occurs at all. The monosubstituted Cp(CO) 2 RePt(μ-C CHPh)[P(OR) 3 ](PPh 3) (R = Pri, Et, Ph) species were also obtained by reacting Cp(CO) 2 Re C CHPh with mixed-ligand complexes Pt(PPh 3) 3 L (L = P(OPri) 3 , P(OEt) 3 , P(OPh) 3). Reactions of Cp(CO) 2 RePt(μ-C CHPh)LL′ (L = L′ = P(OPri) 3 , P(OEt) 3 , P(OPh) 3 ; L = P(OPri) 3 , P(OEt) 3 , P(OPh) 3 , L′ = PPh 3) with Co 2 (CO) 9 yield tricarbonyl vinylidene species Cp(CO) 2 RePt(μ-C CHPh)[P(OR) 3 ](CO) (R = Pri, Et, Ph). The obtained compounds were characterized by IR and 1H, 13C, 31P NMR spectroscopy. The molecular structures of Cp(CO) 2 RePt(μ-C CHPh)[P(OPri) 3 ] 2 , Cp(CO) 2 RePt(μ-C CHPh)[P(OPri) 3 ](PPh 3) and Cp(CO) 2 RePt(μ-C CHPh)[P(OPri) 3 ](CO) were determined by X-ray diffraction study. The redox properties of the new complexes and their reactions of chemical oxidation were studied. [ABSTRACT FROM AUTHOR]

The structure of the vinylidene cluster [η2-Ph2P(CH2)3PPh2]PdFe3(μ4-C=CHPh)(CO)9 was established by X-ray diffraction analysis. The metal core of the molecule has a butterfly shape with the Pd atom occupying a wingtip position. The C(1)=C(2)HPh ligand is σ-bound to three atoms of the Fe2Pd triangle through the C(1) atom and is η2-coordinated to the Fe atom located in the second wingtip position via the C(1)=C(2) double bond. The Pd atom is chelated by the diphosphine ligand. [ABSTRACT FROM AUTHOR]