Double activation of the diphosphinite pincer proligand by a triosmium carbonyl cluster

The reaction between 1,3-bis(diphenylphosphinite)-benzene and Os-3(CO)(10)(MeCN)(2) affords complex Os-3(CO)(10)[1,3-(PhPO)(2)C6H4]. A thermolysis of this cluster in refluxing toluene results in the activation of O-PPh2 and C-H bonds and the formation of unsaturated triosmium cluster Os-3(mu-H)(mu-PPh2)(CO)(7)[(C6H3(O)(OPPh2)] that possesses a remarkable structure with the pseudo-pincer ligand containing a bridging mu-eta(1)-aryl group.