Kinetically stable, four-coordinate V(IV) neopentylidene complexes such as (Nacnac)V:CHtBu(THF) (Nacnac- = [Ar]NC(Me)CHC(Me)N[Ar], Ar = 2,6-(CHMe2)2C6H3), which was prepd. by oxidatively induced alpha-H abstraction from [(Nacnac)V(CH2tBu)2] with AgBPh4 in THF, contain the shortest V:C bonds known to date. [on SciFinder (R)]