A series of imido-Cr(VI) and -(V) complexes have been synthesized and characterized. The structure of the first dicationic Cr(VI) complex [Cr(N^tBu)₂(terpy)](BF₄)₂ (9) has been characterized by X-ray crystallography. The reduction potentials of the imido-Cr complexes have been determined by cyclic voltammetry. 9 undergoes imido transfer reactions with PR₃ to give ^tBuN=PR₃ and [Cr(terpy)(PR₃)₃](BF₄)₃(R=Me (14)). The reaction of 9 with excess of PMe₃ follows biphasic kinetics with rate expressions k2[Cr][PMe₃] and k3[Cr][PMe₃]². At 25.0 ℃ in acetonitrile, k2=0.48 ± 0.1 M^-1s^-1 and k3=1.44 ± 0.16 M^-2s^-l. _{2 3 2 2 3 2 3 2 2 3 6 4 6 4 3 6 2}...[ Read more ]

A series of imido-Cr(VI) and -(V) complexes have been synthesized and characterized. The structure of the first dicationic Cr(VI) complex [Cr(N^tBu)₂(terpy)](BF₄)₂ (9) has been characterized by X-ray crystallography. The reduction potentials of the imido-Cr complexes have been determined by cyclic voltammetry. 9 undergoes imido transfer reactions with PR₃ to give ^tBuN=PR₃ and [Cr(terpy)(PR₃)₃](BF₄)₃(R=Me (14)). The reaction of 9 with excess of PMe₃ follows biphasic kinetics with rate expressions k2[Cr][PMe₃] and k3[Cr][PMe₃]². At 25.0 ℃ in acetonitrile, k2=0.48 ± 0.1 M^-1s^-1 and k3=1.44 ± 0.16 M^-2s^-l.

The interactions of Ru(Et₂dtc)(PPh₃)₂(CO)H with ArSO₂N₃ gave the first Ru(II) arylsulfonylamido complexes Ru(Et₂dtc)(PPh₃)₂-(CO)(NHSO₂Ar) (Ar=p-CH₃C₆H₄(16);p-t-BuC₆H₄ (17);2,4,6-i-Pr₃C₆H₂(18)) in good yields. Protonation of Ru(Et₂dtc)(PPh₃)₂(CO)(NHSO₂Ar) with HX yields complexes of the form Ru(Et₂dtc)(PPh₃)₂(CO)X (X=Cl,OC₆F₅, SC₆F₅). Treatment of the Ru(II) tosylamide complex with I₂ gave the structurally characterized dimer (CO)(Et₂dtc)(PPh₃)Ru(μ-Et₂dtc)(μ-I)Ru(CO)I(PPh₃.

A series of nitrido-Os(VI), -Ru(VI) and -Re(V) complexes of thiolate and fluorinated alkoxide ligands were isolated. Reduction of [OsN(mnt)₂]- by PMe₃ afforded the structurally characterized [ⁿBu₄N][Os(mnt)₂(PMe₃)₂]. Reaction of [OsN(TolS₂)₂- with [Ph₃C]BF₄ yields Os(=NCPh₃)(TolS₂)₂.

Imidochromium complexes were found to catalyze ring-opening of epoxides and N-tosylaziridines with TMSN₃ in good yields. The proposed mechanism of the Cr-mediated ring-opening reactions involves the formation of the azido(imido)-Cr intermediates, which deliver azide to the epoxides.