The dinuclear and trivalent complex {[(Me₃Si)NCH₂CH₂]₂N(Me₃Si)}₂V₂(μ-Cl)₂ (1) is the precursor to mono- and dinuclear alkyl derivatives that are thermally stable. For example, treatment with MeLi gives a stable methyl derivative, probably isostructural with 1, which upon further treatment with pyridine affords the mononuclear complex {[(Me₃Si)NCH₂CH₂]₂N(Me₃Si)}V(CH₃)(pyridine) (2). However, reaction of 1 with Me₂AlCl, AlMe₃, or PMAO-IP yields the tetrametallic species {[(Me₃Si)NCH₂CH₂]₂N(Me₃Si)}₂V₂(μ-Cl)₂(AlMe₂)₂ (3), where the central core of 1 was preserved except for the vanadium centers, which were reduced to the divalent state. The two Me₂Al residues remained coordinated to the amido ligand. The reduction of vanadium to the divalent state relates to the relatively short life of 1 as an ethylene polymerization catalyst. A similar reaction of 1 with AlCl₃ resulted in disproportionation forming the tetravalent complex {[(Me₃Si)NCH₂CH₂]₂N(Me₃Si)}VCl₂AlCl₃ (4) and the pentanuclear mixed-valent V(II)/V(III) species [(AlCl₂){[(Me₃Si)NCH₂CH₂]₂N(Me₃Si)}V]₂[(μ-Cl)₆V]·(toluene)₂ (5). The fact that complex 5 contains a divalent vanadium atom stripped of its ligand system indicates that two different reaction mechanisms are operating to reduce the vanadium center and that the differing Lewis acidity of the two aluminum species is the determining factor.