SYNTHESIS AND REACTIVITY OF THE PHOSPHIDO-BRIDGED COMPLEX [CP(2)TA(MU-CO)(MU-PME(2))CR(CO)(4)]MU-PME2)CR(CO)4]

The heterobimetallic complex [Cp(2)Ta(CO)(mu-PMe(2))Cr(CO)(5)] 1 was prepared by reaction of [Cp(2)Ta(CO)(PMe(2))] with [Cr(CO),THF]. Irradiation of 1 afforded the dibridged compound [Cp(2)Ta(mu-CO)(mu-PMe(2))Cr(CO)(4)] 2. Addition reactions between 2 and Lewis bases L (L = phosphines, or isonitriles) produced [Cp(2)Ta(CO)(mu-PMe(2))Cr(CO)(4)(L)] 3(a, b) with L regiospecifically coordinating to Cr. Depending on L, the reaction may be stereospecific, since the coordination of L can lead to cis or trans arrangements on the Cr site.