The synthesis of alkylated η5-cyclopentadienylvanadium(V) complexes tC4H9N=VCpRCl2 (CpR = C5H4R, C5H3R2, C5HMe4, C5Me5) is described. The compounds have been investigated by 51V NMR spectroscopy; the 51V resonances are found downfield of the unsubstituted complex tC4H9N=V(η5-C5H5)Cl2. The deshielding of the 51V nucleus increases with the number of substituents R