RESUMO
The reactions of [W(îCBr)(CO)2(Tp*)] (Tp* = tris(dimethylpyrazolyl)borate) with LiTeCîCR (R = SiMe3, SiiPr3, iPr, nBu, tBu, Ph, C6H4Me-4, methylimidazol-2-yl) afford the first alkynyltellurolatocarbynes [W(îCTeCîCR)(CO)2(Tp*)]. Both the WîC and CîC multiple bonds are prone to metal addition as exemplified by treatment with [MCl(SMe2)] (M = Cu, Au) to afford the hexametallic complex [W2Cu4(µ-CTeCîCSiiPr3)2Cl4(CO)4(Tp*)2] and [WAu(µ-CTeCîCSiMe3)Cl(CO)2-(Tp*)] which evolves to the unusual hypervalent [WAu(µ-CTeCl4)(SMe2)(CO)2(Tp*)].
RESUMO
The new bis(alkynyl)mercurial Hg{CîCSeCîW(CO)2(Tp*)}2 (Tp* = tris(dimethylpyrazolyl)borate) forms adducts with fluoride and phenathroline, the structures of which are interpreted in the context of two-coordinate mercury presenting a σ-torroid for spodium bonding.
RESUMO
The halocarbyne complexes [M(îCX)(CO)2(Tp*)] (M = Mo, W; X = Cl, Br; Tp* = hydrotris(dimethylpyrazolyl)borate) react with [AuCl(SMe2)], [Pt(η2-H2CîCH2)(PPh3)2] or [Pt(η2-nbe)3] (nbe = norbornene) to furnish rare examples of µ2-halocarbyne complexes [MAu(µ2-CX)Cl(CO)2(Tp*)], [MPt(µ2-CCl)(CO)2(PPh3)2(Tp*)] and [W2Pt(µ2-CCl)2(CO)4(Tp*)2]. The complex [WPt(µ2-CCl)(CO)2(PPh3)2(Tp*)] spontaneously rearranges to the µ2-carbido complex [WPt(µ2-C)Cl(CO)2(PPh3)2(Tp*)] during silica-gel chromatography. One phosphine ligand of [WPt(µ2-CCl)(CO)2(PPh3)2(Tp*)] is readily substituted by CO to afford [WPt(µ2-CCl)(CO)3(PPh3)(Tp*)]. These µ2-halocarbyne complexes have been interrogated by spectroscopic, crystallographic and computational methods, the latter by reference to data for terminal halocarbyne precursors [M(îCX)(CO)2(Tp*)].
RESUMO
The chemistry of transition metal carbynes, Ln M≡CR, has historically been dominated by species bearing hydrocarbyl or amino 'R' substituents, with other elements appearing only sporadically. In recent years, carbynes and related 'C1 ' species bearing other main-group substituents, particularly heavier elements of the p-block, have begun to emerge. This review details the chemistry of heavier pnictogen-functionalised C1 ligands, MCARn (A=P, As, Sb, Bi; n=0-3), including their syntheses, properties and reactivities, and how these are distinguished from more traditional carbyne complexes. Recent developments in the closely related phospha-isonitrile Ln M(CPR), cya-phosphide and cya-arside ligands, Ln M(C≡A) (A=P, As), are also discussed.
RESUMO
Heterobi- and tetrametallic phosphoniocarbyne bridged complexes [WAu(µ-CPMe2Ph)Cl(CO)2(Tp*)]+ (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate), [W2Cu2(µ-CPMe2Ph)2(µ-Cl)2(CO)4(Tp*)2]2+ and [WPt(µ-CPMe2Ph)(COD)(CO)2(Tp*)]+ (COD = 1,5-cyclo-octadiene) arise from the reactions of the mononuclear terminal phosphoniocarbyne [W([triple bond, length as m-dash]CPMe2Ph)(CO)2(Tp*)]PF6 with [AuCl(THT)] (THT = tetrahydrothiophene), [CuCl(SMe2)] and [Pt(nbe)3] (nbe = norbornene) in the presence of COD. The COD ligand in [WPt(µ-CPMe2Ph)(COD)(CO)2(Tp*)]+ is labile and readily replaced by isonitriles to provide [WPt(µ-CPMe2Ph)(CNR)2(CO)2(Tp*)]+ (R = tBu, C6H2Me3-2,4,6) with retention of the tungstaplatinacyclopropene core, the bonding within which was computationally interrogated.
RESUMO
The first examples of bi- and polynuclear tellurocarbonyl complexes were obtained from the reactions of [W(≡CTe)(CO)2 (Tp*)]NEt4 (Tp*=hydrotris(dimethylpyrazolyl)borate) with [MCl(PCy3 )]/TlPF6 (M=Cu, Au) or [Au2 Cl2 (µ-dppm)], which afford [WM(µ-CTe)(PCy3 )(CO)2 (Tp*)] (M=Cu, Au) and [WAu2 (µ-CTe)(µ-dppm)(CO)2 (Tp*)]3 (PF6 )3 . In all cases it is specifically the tellurocarbonyl that assumes a bridging, but in each case distinct, role including examples of isotellurocarbonyl, semi-bridging and σ-π coordination and combinations thereof. Tetrametallic complexes bridged by C2 Te and C2 Te2 ligands are also described.
RESUMO
The reaction of alkynylselenolatoalkylidynes [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CR)(CO)2(Tp*)] (R = SiMe3, SiiPr3, Ph, p-tolyl, tBu, CPh3, SiPh3, GePh3; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with [AuCl(L)] (L = tetrahydrothiophene, SMe2) readily furnishes heterobimetallic complexes [WAu(µ-CSeC[triple bond, length as m-dash]CR)Cl(CO)2(Tp*)] where gold(i) chloride coordinates to the tungsten-carbon multiple bond. Alternatively, desilylation of the SiMe3 complex [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CSiMe3)(CO)2(Tp*)] in the presence of gold phosphine complexes [AuCl(PR'3)] (R' = Ph or Cy) furnishes the gold alkynyl derivatives, [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CAuPR'3)(CO)2(Tp*)].
RESUMO
The reactions of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with lithium alkynylselenolates LiSeC[triple bond, length as m-dash]CR (R = SiMe3, SiiPr3, nBu, tBu, Ph, p-tolyl) afford the alkynylselenolatoalkylidyne complexes [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CR)(CO)2(Tp*)]. Desilylation of the SiMe3 complex furnishes the parent [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CH)(CO)2(Tp*)], which may be further derivatised by deprotonation and treatment with triphenylcarbenium or triphenylmetal chlorides to give mixed-heteroatom products [W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CEPh3)(CO)2(Tp*)] (E = C, Si, Ge, Sn, Pb). This procedure extends to dichlorosilanes, whereby the unusual bimetallic complexes [(Tp*)(CO)2W[triple bond, length as m-dash]CSeC[triple bond, length as m-dash]CSiRR'C[triple bond, length as m-dash]CSeC[triple bond, length as m-dash]W(CO)2(Tp*)] (R, R' = Ph, CH3) are obtained, bridged by unsaturated units interrupted by two different main-group heteroatoms. Finally, the trimetallic analogues, [{(Tp*)(CO)2W([triple bond, length as m-dash]CSeC[triple bond, length as m-dash]C)}3SiR] (R = Ph, Et), may be prepared in the same manner from appropriate organotrichlorosilanes.
