Some complexes containing carbon chains end-capped by M(CO)2Tp′ [M=Mo, W; Tp′=HB(pz)3, HB(dmpz)3] groups

Pentadiynylidyne and Pentacarbido Complexes

“…Treating 2 with [RuCl(PPh 3 ) 2 (η‐C 5 H 5 )] in the presence of KF in methanol/THF (1:1) allowed the isolation of the bimetallic pentacarbido complex [(Tp*)(CO) 2 W(μ‐CC≡CC≡C)Ru(PPh 3 ) 2 (Cp)] ( 5 ) in 74 % yield (Scheme , Figure ). This reagent was chosen because the corresponding tricarbido complex [(Tp*)(CO) 2 W(μ‐CC≡C)Ru(PPh 3 ) 2 (Cp)] ( 6 ) is known and because the only previously reported bimetallic pentacarbido complex other than the cumulenic ReC 5 Mn complex discussed above is [(Tp*)(CO) 2 Mo(μ‐CC≡CC≡C)Ru(dppe)(Cp*)] ( 7 , Cp*=η‐C 5 Me 5 ), which arose from the Pd 0 /Cu I mediated reaction of [Mo(≡CBr)(CO) 2 (Tp*)] with [Ru(C≡CC≡CAuPPh 3 )(dppe)(Cp*)] …”

“…This reagent was chosen because the corresponding tricarbido complex [(Tp*)(CO) 2 W(m-CCC)Ru(PPh 3 ) 2 (Cp)] (6)i s known [4f] and because the only previously reported bimetallic pentacarbido complex other than the cumulenic ReC 5 Mn complex discussed above [7] is [(Tp*)(CO) 2 Mo(m-CC CC C)Ru(dppe)(Cp*)] (7,Cp* = h-C 5 Me 5 ), which arose from the Pd 0 /Cu I mediated reaction of [Mo(CBr)(CO) 2 (Tp*)] with [Ru(CCCCAuPPh 3 )(dppe)(Cp*)]. [11] Bond localization along the WC 5 Ru spine of 5 (Table 2, Figure 4) is entirely consistent with the effective atomic number requirements of the 15-electron tungsten and 17-electron ruthenium termini, calling for WCtriple and RuÀC single bonds,r espectively.…”

Reactions of [Mo(≡CBr)(CO)2{HB(pzMe2)3}] (pz = pyrazol-1-yl) with Amines: Synthesis of Amino, Pyridinium, and Thiolato Carbyne Complexes

“…The complex 1 is readily available from [Mo (CO) 6 ], and although the direct reactions of this complex with nucleophiles have not been reported, there is copious precedent involving the analogous chlorocarbyne complexes [M(tCCl)(CO) 2 {HB(pzMe 2 ) 3 }] (M ) Mo, W) 17 and also of the palladium-catalyzed reactions of 1 with gold alkynyls. 18 None of these reports involve nitrogenbased nucleophiles.…”

Pentadiynylidyne and Pentacarbido Complexes

“…In conclusion, we have shown that 1) pentadiynylidyne ligands are viable and accessible;2 )the photophysical properties arise from transitions between frontier orbitals that intimately combine both metal and carbon-chain character;and 3) they may serve as building blocks for assembling bi-and tri-metallic pentacarbido complexes,the carbon wires of which by necessity involve metal-carbon multiple bonding in contrast to even-numbered dimetalated carbon chains.This synthetic approach offers some generality,a dding to the two previously known examples of pentacarbido bridged bimetallics,[ ( h-C 5 Cl 5 )(CO) 2 Mn(m-C 5 )Re(NO)(PPh 3 )(h-C 5 Me 5 )]BF 4 [7] and [(Tp*)(CO) 2 Mo(m-C 5 )Ru(dppe)(h-C 5 Me 5 )]. [11] We therefore suggest that carbyne-based carbon-wire ligands offer exactly the same features,a lbeit enhanced, that have made conventional poly-yn-diyl based carbon-wire materials such afertile area for study.…”