Ruthenium metal core geometry

Thermolysis of Ru3(CO)i2 with 3 equiv. of the cyclic phosphine P4Bu 4 in xylene affords a mixture of products, including nonanuclear Ru9(/t3-H)(/t-H)2(/t7-P)(/t3-PBu )3(CO)20 311, hexanuclear 263, and heptanuclear 298. The metal core is based on a dibridged square-pyramidal geometry, with two additional ruthenium atoms forming an arch across the square face. The phosphorus atom is bound to seven metal atoms in a semi-encapsulated position. The complex contains 132 c.v.e., two more than predicted. ... 

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