Products of the reaction of carbon monoxide with [Os 6 (CO) 18 ]; X -ray crystal structure of [Os 5 (CO) 19 ]

The new clusters [Os5(CO)19] and [Os6(CO)20] have been prepared from the reaction of [Os6(CO)18] with CO; the Os atom arrangement in the former has been found to be two isosceles triangles sharing the vertex.