Dimetallapoly‐yn‐diylidynes: L_nM≡C−(C≡C)_x−C≡ML_n (x=0–4)

Abstract

Synthetic routes to dimetallated Cx carbon wires in which two metals are separated by a linear carbon chain involving terminal metal–carbon triple bonds are described for the complexes [(Tp*)(CO)2W≡C−(C≡C)n−C≡W(CO)2(Tp*)] (Tp*=hydrotris(dimethylpyrazolyl)borate) where n=1, 3 or 4, joining the previously known examples with n=0, 1 and 2 to complete the series as models for linear carbyne C∞.

A review of functional linear carbon chains (oligoynes, polyynes, cumulenes) and their applications as molecular wires in molecular electronics and optoelectronics

“…3. 63 The synthetic achievements highlighted above have given unprecedented opportunities to explore the effect of increasing oligoyne length on the molecules' spectroscopic properties in solution, and on the bond length alternation and geometry in the solid state, allowing extrapolation to the properties of carbyne. UV-visible and Raman spectroscopy are commonly used techniques, although a complicating factor is that some endcapping units can participate in intramolecular charge transfer, with an obvious larger effect in shorter wires.…”

Pnictogen‐Functionalised C1 Ligands: MC‐ARn (n=0, 1, 2, 3)

“…Oxidative addition of bromocarbynes 5 a or 5 b to [Pd(PPh 3 ) 4 ] gives isolable μ‐carbido complexes [(Tp*)(CO) 2 M≡C−Pd(PPh 3 ) 2 Br] (M=Mo, W), [26] which can feed into catalytic cycles comparable to organic analogues [26b] . This strategy has recently been used to prepare propargylidyne and pentadiynylidyne derivatives, L n M≡C(C≡C) n R ( n =1, 2) in what can be considered as pseudo‐Sonogashira couplings [16c–e] …”

Rhenium Alkyne Catalysis: Sterics Control the Reactivity

“…Beyond the traditional d 0 Mo/W systems, Schrock proposed non-d 0 transition-metal (TM) alkylidyne complexes, enhancing the catalysts stability and substrate scope. Note that examples of this type of systems increased substantially in the last years . Since the insights reported by Ehrhorn and Tamm, this challenge remained unexplored until 2020 with the disclosure of a d 2 Re­(V) alkylidyne by Williams, Jia, and co-workers.…”

“…Note that examples of this type of systems increased substantially in the last years. 29 Since the insights reported by Ehrhorn and Tamm, 7 this challenge remained unexplored until 2020 with the disclosure of a d 2 Re(V) alkylidyne by Williams, Jia, and co-workers. This complex exhibited low activity yet remarkable air stability, catalyzing alkyne metathesis in the presence of traces of water and demonstrating compatibility with a wide range of functional groups (see Scheme 2 a).…”