Chromium chalcogen complexes. Insertion of elemental sulphur into [{Cr(cp)(CO)2}2Se] and [Cr(cp)2(CO)4Se2](cp =η-C5H5)

Abstract

The facile insertion of elemental sulphur into the cumulated linear triple bond CrSeCr, of [Cr₂(cp)₂(CO)₄Se](cp =η-C₅H₅) resulted in the isolation of [Cr₂(cp)₂(CO)₄Se₂], [Cr₂(cp)₂(CO)₄S₂], and [Cr₂(cp)₂(CO)₄S], with relative yields dependent on the reaction conditions, as well as the sulphur selenides S₇Se and S₆Se₂. Detailed n.m.r. and t.l.c. studies indicated that the transformation occurred via dichalcogen species of the type [Cr₂(cp)₂(CO)₄S(Se)] and [Cr₂(cp)₂(CO)₅S(Se)]. It was demonstrated that [Cr₂(cp)₂(CO)₄Se₂] also can undergo a rapid reaction with elemental sulphur to give [Cr₂(cp)₂(CO)₄S] as the ultimate product.