(η-C5Me5)Ta(CH2CH2CMe3)2(η2-CHPMe2): a stable sixteen electron long-chain di-alkyl compound of tantalum

Abstract

Neohexene inserts into the Ta–H bonds of (C₅Me₅)Ta(H)₂(η²-CHPMe₂)(PMe₃)(1) to give the co-ordinatively unsaturated neohexyl hydride (C₅Me₅)Ta(H)(CH₂CH₂CMe₃)(η²-CHPMe₂)(2) followed by the bis(neohexyl) compound (C₅Me₅)Ta(CH₂CH₂CMe₃)₂(η²-CHPMe₂)(3) whose X-ray structure is reported: the stability of these long-chain tantalum alkyls may be understood by comparison with pseudo-isoelectronic Group 4 metallocenes.