The first arylimido compounds of chromium(VI), CrCl₂(NR)₂(R = 2,4,6-Me₃H₂C₆ or 2,6-Me₂H₃C₆), have been made by interaction of CrCl₂(NBu^t)₂ with the aryl isocyanates. Similar interaction with 2,6-Prⁱ₂C₆H₃NCO gave a dimeric chromium(V) compound [CrCl(µ-NBu^t)(NC₆H₃Prⁱ₂-2,6)]₂. The chloride CrCl₂(NC₆H₂Me₃-2,4,6)₂ formed adducts with Lewis bases, e.g. CrCl₂(NC₆H₂Me₃-2,4,6)₂(PMe₃)₂ and [Cr(NC₆H₂Me₃-2,4,6)₂(terpy)][BF₄]₂(terpy = 2,2′ : 6′,2″-terpyridine) was obtained with AgBF₄. Substitution of Cl atoms occurred with NaR′(R′= OSiMe₃, OC₆H₂Me₃-2,4,6, SC₆H₂Me₃-2,4,6, SC₆F₅ or SC₆H₂Prⁱ₃-2,4,6) and with Grignard reagents, MgR″Br (R″= CH₂CMe₃, CH₂CMe₂Ph or CH₂Ph) giving in all cases compounds of the type Cr(NC₆H₂Me₃-2,4,6)₂R′₂ or Cr(NC₆H₂Me₃-2,4,6)₂R″₂. The alkyl compounds underwent insertion with Bu^tNC, or 2,6-Me₂H₃C₆NC to give η²-iminoacyl compounds or Cr^VI and reduction by PMe₃ on heating to give the chromium(IV) dimer [Cr(µ-NC₆H₂Me₃-2,4,6)(NC₆H₂Me₃–2,4,6)(PMe₃)]₂. The interaction of CrCl₂(NC₆H₂Me₃-2,4,6)₂ with the Grignard reagent derived from 4-tert-butylbenzyl chloride gave not a dialkyl but an amidochromium(IV) dimer {CrCl(µ-NC₆H₂Me₃–2,4,6)[N(CH₂C₆H₄Bu^t-4)(C₆H₂Me₃-2,4,6)]}₂, while on interaction with MgEtBr in the presence of PMe₃ it gave the dichromium(V) compound (2,4,6-Me₃H₂C₆N)BrCr(µ-NC₆H₂Me₃-2,4,6)₂CrBr(NC₆H₂Me₃-2,4,6)(PMe₃). The crystal structures of seven compounds have been determined, in six of which the Cr atoms have slightly distorted tetrahedral geometry, while in the remaining compound one atom is tetrahedral and the other five-co-ordinate. The geometries of the Cr₂N₂ rings in four of the compounds are indicative of some direct Cr ⋯ Cr interaction.