Os3(co)u(m-ch2) (1) reacts with (Ph3P)2Pt(C2H2) to give the new tetranuclear cluster Os3Pt(M-CH2)(CO)u(PPh3)2 (2) in which the methylene ligand bridges an Os-Pt bond. Compound 2 has been characterized spectroscopically and by an X-ray diffraction study. It crystallizes in the space group C2/c with a = 39.18 (2) A, 6 = 15.200 (6) A, c = 18.532 (7) A, 0 = 91.17 (3)°, V = 11034 (8) A3, and Z « 8. The structure has been refined for the 3258 reflections with F0> 5<r(F0) to R and RwFvalues of O.0557 and O.0624. The cluster has a “spiked triangular” geometry with the Pt atom bonded to only one Os of the Os3 triangle. The methylene ligand bridges the Os-Pt bond, and the Pt is further coordinated by two PPh3 ligands. Compound 2 readily and reversibly exchanges CO for PPh3 at the Pt center. Magnetization-transfer experiments CH, 13C) have shown that the inequivalent methylene hydrogens in the parent cluster 1 undergo slow exchange, but the spectral evidence does not imply the intermediacy of a terminal Os=CH2, in contrast to the recently reported fluxional properties of ru3(co)u(m-ch2).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry