Flash Communication: Challenges in the Characterization of a Bisphosphine Nickel Fluoride Complex.

A prior report (Inorg. Chim. Acta 2011, 376, 118-122) detailed the use of "[Ni-(THF)6]-[(BF4)2]" to prepare [(dtbe)-Ni-(μ-F)]2[BF4]2 (dtbe = 1,2-bis-(di-tert-butylphosphino)-ethane) using a DCM/THF (1:1) solvent system. Here we describe a procedure that affords [Ni-(THF)4(BF4)2] in the solid-state, and note that reaction of [Ni-(THF)4(BF4)2] with the similar phosphine dcpe (dcpe = 1,2-bis-(dicyclohexylphosphino)-ethane) only produces [(dcpe)-Ni-(μ-F)]2[BF4]2 when run in thoroughly dried THF solvent. If a 1:1 mixture of DCM/THF solvents is used as previously described, the bridging chloride derivative [(dcpe)-Ni-(μ-Cl)]2[BF4]2 is formed. Moreover, we show that bridging fluorides of [(dcpe)-Ni-(μ-F)]2[BF4]2 can be short-lived in solution, reacting with the medium to produce unexpected products.