Tantalum complexes carbyne

In the tantalum-carbyne complex Li (dmp)[(CH3)3CCH2]3Ta=CC-(CH3)3 (77) (dmp = 1,4-dimethylpiperazine) 101), tetrahedral coordination of the lithium atom is achieved by interaction with a saturated CH2 group, the unsaturated carbyne carbon, and the two donor atoms from dimethylpiperazine. Evidently, Li—H—C interactions are involved. 

The tantalum carbyne complex [Ta(CH2CMe3)3(CCMe3)] reacts with CF3COOD to give [Ta(CH2CMe3)3(CDCMe3)]. 

Scheme 8.12 Preparation of the first bis(carbene) tantalum complexes 46 and 48 from mono(carbene) or mono(carbyne) tantalum compounds as starting materials...

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