A Structurally Characterized Fluoroalkyne

The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M-C≡CF, is reported. Reaction of [Ru(C≡CH)(η⁵ -C₅ Me₅ )(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η⁵ -C₅ Me₅ )(dppe)][N(SO₂ Ph)₂ ]. Subsequent deprotonation with LiN(SiMe₃ )₂ affords the fluoroalkynyl complex [Ru(C≡CF)(η⁵ -C₅ Me₅ )(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF₂ )(η⁵ -C₅ Me₅ )(dppe)][N(SO₂ Ph)₂ ].