Unexpected reactions of chromium hydrides with a diazoalkane

The reaction of dinuclear chromium hydride [(2,6-Me2Ph)(2)nacnacCr(mu-H)](2) ((2,6-Me2Ph)(2)nacnac = N,N'-bis(2,6-dimethylphenyl)-2,4-pentanediiminato) with trimethylsilyl-diazomethane did not yield the desired, known alkyl hydride [(2,6-Me2Ph)(2)nacnacCr](2)(mu-H)(mu-CH2SiMe3). Rather, it resulted in an unexpected mixture of novel chromium complexes, which have been structurally characterized. They include macrocyclic dinitrogen complexes, namely [(2,6-Me2Ph)(2)nacnacCr(THF)(mu-N-2)](3) (4) and [(2,6-Me2Ph)(2)nacnacCr(mu-N-2)](4) (5). Other products containing various fragments of the diazo-reagent were [(2,6-Me2Ph)(2)nacnacCr](2)(mu-N)(mu-H) (6), [(2,6-Me2Ph)(2)nacnacCr](2)(mu-NSiMe3)(mu-H) (7) and [(2,6-Me2Ph)(2)nacnacCr](2)(mu-N=CH2)(mu-NH) (8). An analogous reaction of the sterically more encumbered [(2,6-iPr(2)Ph)(2)nacnacCr(mu-H)](2) ((2,6-Me2Ph)(2)nacnac = N,N'-bis(2,6-diisopropylphenyl)-2,4-pentanediimi-nato) produced [(2,6-iPr(2)Ph)(2)nacnacCr(mu-N)(mu-N(H)NC(H)SiMe3)](2) (9). (C) 2018 Elsevier Ltd. All rights reserved.