摘要
Reactions of nitriles RCN with the sterically encumbered Mo(N[t-Bu]Ar) 3 (1, Ar = 3,5-C 6 H 3 Me 2 ) or the somewhat less hindered Mo(H)(η 2 -Me 2 CNAr)(N[i-Pr]Ar) 2 (2) have been investigated. Where R = Me or Ph, reaction with 1 results in reductive nitrile coupling and the formation of a diiminato product [u-NC(R)C(R)N][1] 2 . In contrast, reaction of 1 with Me 2 NCN surprisingly results in a stable, albeit highly congested, η 2 adduct of the nitrile. When the less sterically hindered 2 is used, reaction with PhCN gives the diiminato product analogous to the one mentioned for the tert-butyl system, [u-NC(Ph)C(Ph)N] [Mo(N[i-Pr]Ar) 3 ] 2 , where molybdaziridine-hydride 2 has provided access to the three-coordinate Mo(N[i-Pr]Ar) 3 (3) moiety. Use of a more bulky nitrile such as MesCN (Mes = 2,4,6-C 6 H 2 Me 3 ) results in formation of a bis-η 1 compound, (η 1 -MesCN) 2 [3], Use of 9-anthracenylcarbonitrile results in head-to-tail C-C coupling of two monomers via the anthracenyl moiety. Detailed variable-temperature EPR and 2 H NMR data are included for both molybdenum-containing starting materials and selected reaction intermediates and products. © 2003 American Chemical Society.