A NOVEL HEXAOSMIUM CLUSTER [OS-6(MU-H)(CO)(19)(MU-CO)(ETA(2)-C6F5NNNC6F5)] FORMED FROM AN ISOMERIC INTERMEDIATE [OS-6(MU-H)(CO)(20)(NCME)(2)(ETA(2)-C6F5NNNC6F5)] VIA A CAPPING PROCESS

A novel hexaosmium cluster [Os-6(mu-H)(CO)(19)(mu-CO)-(eta(2)-C6F5NNNC 6F5)] is obtained in the reaction of C6F5N=NNHC6F6 with [Os-3(CO)(10)( NCMe)(2)] and is fully characterized in the solid state by single-crys tal X-ray diffraction analysis; investigation of its formation reveale d the interesting capping of one end of a linear triosmium fragment on to the triangular face of [Os-3(CO)(10)(NCMe)(2)] via a 'spiked' isome ric intermediate Os-6(mu-H)(CO)(20)-(NCMe)(2)(eta(2)-C6F5NNNC6F5)], of Which the structure in solution was proposed based on C-13 NMR studie s.