EXPERIMENTAL AND THEORETICAL-STUDY OF THE REACTIVITY OF CLUSTER-BOUND DICARBON - SYNTHESIS AND STRUCTURES OF NOVEL ELECTRON-RICH RU5 CLUSTERS

An EHMO (extended Huckel molecular orbital) study of [Ru5(mu5-C2)(mu-SH)2(mu-PH2)2(CO)11] suggests that C(beta) should behave as a nucleophile; this is found experimentally in the reactions of the SMe-PPh2 derivative with H-2 or C2H4, in which C(beta) inserts into H-H or C-H bonds to give mu3-CCHR ligands (R = H or CH=CH2, respectively), as shown by X-ray structure determinations carried out on [Ru5(mu3-CCHR)(mu3-SMe)2(mu-PPh2)2(CO)10] (R=H and CH=CH2).