New families of coordinated carbon: oxidative coupling and cross-coupling of a transition metal butadiynyl complex to bimetallic M–CCCCCCCC–M and M–CCCCCC–M adducts

Abstract

[(η⁵-C₅Me₅)Re(NO)(PPh₃)(CCCCCCCC)(Ph₃P)(ON)Re(η⁵-C₅Me₅)] and [(η⁵-C₅Me₅)Re(NO)(PPh₃)(CCCCCC)-(Ph₃P)(ON)Re(η⁵-C₅Me₅)], which contain the longest chains of elemental carbon tethered between two transition metals to date, are prepared by Cu(OAc)₂ coupling of [(η⁵-C₅Me₅)Re(NO)(PPh₃)(CCCCH)], or cross-coupling with the corresponding ethynyl complex; unusual spectroscopic and redox properties are described.