T-Butylimido and t-butylimido oxo aryls of rhenium. X-ray crystal structures of Re(NBu t) 2(2,6-Me 2C 6H 3) 2, Re(NBu t)(2,4,6-Me 3C 6H 2)(C 27H 32), Re(NBu t) 3(2,4,6-Me 3C 6H 2), [(Bu tN)Br(2,4,6-Me 3C 6H 2)Re(μ-NBu t)(μ-O) [formula omitted](OC 6H 2Me 2CH 2)(NBu t)], [Re(NBu t)(O)Ar(μ-O)] 2, Ar = 2,6-C 6H 3 and 2,4,6-C 6H 2

Abstract

The interaction of Re(NBu t ) 2Cl 3 with 2,6-xylyl magnesium bromide gives rise to the paramagnetic rhenium(VI) compound, Re(NBu t ) 2(xyl) 2, which is readily oxidized to the cation [Re(NBu t ) 2(xyl) 2] +, isolated as its PF 6 − salt; the latter with Bu t NC gives the iminoacyl cation [Re(NBu t ) 2(xyl)(Bu t NCxyl)] +. An unstable rhenium(V) anion, [Re(NBu t ) 2(xyl) 2] −, has been characterized. Interaction of Re(NBu t ) 2Cl 3 with excess mesityl Grignard gives a compound of stoichiometry Re(NBu t )(mes)(C 27H 32) in which three aromatic rings are coupled, the central one comprising a η 5-cyclohexadienyl ring bearing an exo-mesityl group in the 1-position and in the 3-position linked by a CH 2 group to an aryl group σ-bonded to the metal, which is formally in the V oxidation state. The compound Re(NBu t ) 2Cl( o-tol) 2 has been synthesized; treatment with AgPF 6 produces the salt [Re(NBu t ) 2( o-tol) 2]PF 6. Hydrolysis of Re(NBu t ) 2ReCl 3 with LiOH gives Re(NBu t ) 2 Cl(OH) 2, which on arylation, gives the oxo imido species Re(NBu t ) 2(O)mes and [(Bu t N)Br(mes)Re(μ-NBu t )(μ-O)Re(OC 6H 2Me 2CH 2)(NBu t ) 2]. Interaction of excess NO with Re(NBu t ) 2Ar 2, Ar = 2,6-xylyl and mesityl, gives the compounds [Re(NBu t )(O) (μ-O)Ar] 2; the reaction involves a unique NN bond formation to give Bu t NNAr. Stoichiometric reactions of Re(NBu t ) 2(xyl) 2 and NO lead to the complexes Re(NBu t )2 (xyl) 2NO and Re(NBu t ) 2(O)(xyl). Mechanisms for the NO reactions are proposed. X-ray structures of the compounds listed in the title have been determined; the compounds [Re (NBu t )(O)(μ-O)Ar] 2 have asymmetric oxo bridges.