The Unusual Stability of Homoleptic Di- and Tetravalent Chromium Alkyls

Reaction of CrCl3(THF)3 with 3 equiv of R−M [R = Me3CCH2 (a), Me3SiCH2 (b)] afforded
either the previously reported tetravalent homoleptic R4Cr (1a, b) [M = MgCl] or the
unprecedented divalent and tetranuclear homoleptic [R2Cr]4 (2b) [M = Li]. Both types of
compounds display a remarkable chemical inertness toward proton transfer agents but
readily react with ethylene.

CrCl3(THF)3与3当量的R−M [R = Me3CCH2 (a), Me3SiCH2 (b)]反应，产生了先前报道的四价均相化合物R4Cr (1a, b) [M = MgCl]或前所未有的二价及四核均相化合物[R2Cr]4 (2b) [M = Li]。这两种类型的化合物对质子转移剂表现出显著的化学惰性，但与乙烯反应迅速。