The compound Cr(NBu^t)Cl3, isolated as its adducts with tetrahydrofuran (thf) and 1,2-dimethoxyethane (dme), has been prepared by chlorination of Cr(NBu^t)2Cl2. These materials have been used as sources of other chromium compounds such as the neutral adducts Cr(NBu^t)Cl3(PR3)2(R3= Me3, Et3, Me2Ph or EtPh2) or Cr(NBu^t)Cl2(NC7H13)(NC7H13= quinuclidine) or anionic complexes such as [PPh4][Cr(NBu^t)Cl4]. The tertiary phosphine complexes in the presence of excess of phosphine are photochemically or thermally reduced to CrCl3(PR3)3 and the tertiary phosphinimine. Halide-substitution reactions on Cr(NBu^t)Cl3(dme) or [Cr(NBu^t)Cl4]^â with O,N, (O,N) and S ligands give rise to compounds such as cis-Cr(NBu^t)Cl(OC9H6N)2(OC9H6N = quinolin-8-olate), [Cr(NBu^t)(mnt)2]^â(mnt = maleonitriledithiolate) and Cr(NBu^t)Cl(S2CNEt2)2; cyclic voltammetry of the last two complexes is reported. Evidence for the disproportionation 2Cr^Vâ Cr^VI+ Cr^IV in reactions of alkoxides is given. Reduction of Cr(NBu^t)Cl3(dme) in the presence of 1,2-bis(dimethylphosphino)ethane (dmpe) gives the chromium(IV) species [Cr(NBu^t)(dmpe)2Cl]Cl. The EPR (X-band) spectra of chromium(V) species at room temperature show hyperfine splitting for ⁵³Cr, ¹⁴N and ³¹P in appropriate compounds with g iso values at 77 K of ca. 2.00. The compounds [V(NBu^t)(NHBu^t)(µ-NBu^t)]2 and [V(µ-NBu^t)(OSiMe3)2]2 are also described. The X-ray structures of five compounds have been determined: Cr(NBu^t)Cl3(dme) is octahedral with a mer arrangement of the three chlorines; Cr[C6H4(NH)2-o]Cl2(PMe2Ph)2 is also octahedral, having C 2 symmetry with trans phosphines and cis chlorines; Cr(NBu^t)2(OSiPh3)2 is distorted tetrahedral; Cr(NBu^t)Cl(OC9H6N)2 is octahedral with the chelating quinolin-8-olato groups arranged to give trans O,O and cis N,N geometry; and [Cr(NBu^t)(mnt)2]^â has a square-pyramidal structure with an axial imido group.