The reaction of [Os3(μ-H)(CO)10(μ-CO)]− with Ph2SbCl: a cluster with a six-membered Os4Sb2 ring and another with fluxional metal–metal bonds †

Abstract

Besides the cluster [Os3(μ-H)(μ-SbPh2)(CO)10], 1, other products identified from the reaction of [Os3(μ-H)(CO)10(μ-CO)]− with Ph2SbCl in THF were [Os3(μ-SbPh2)2(CO)10], 2a, and a dimeric form of 1, viz. [Os3(μ-H)(μ-SbPh2)(CO)10]2, 3. Carrying out the reaction in CH2Cl2 gave 3 as the major product, while 2a has been demonstrated to result from the reaction of 1 with Ph2SbCl. In 2a the Os3Sb2 unit is almost planar; one of the Ph2Sb bridges is open while the other is closed. The two Ph2Sb-bridged Os–Os edges are shown by EXSY and variable-temperature 1H NMR spectroscopy on the analogue [Os3(CO)10(μ-SbPh2){μ-Sb(C6H4Me-p)2}], 2b, to interchange via an Os–Os bond fluxion.