The reaction (room temperature, diethyl ether) of [Pt2(μ-cod)(PEt3)4] (cod = cyclo-octa-1,5-diene) with nido-5,6-C2B8H12 affords [9-H-9,9(Et3P)2-μ10,11-H-7,8,9-C 2PtB8H10] (1), structurally characterised by X-ray diffraction. Crystals are orthorhombic, space group P212121, with four molecules in a unit cell of dimensions a = 14.825(4), b = 10.1367(13), and c = 16.1193(15) Å. Using 3 303 amplitudes recorded at 293 K the structure has been refined to R = 0.0575 (R′ = 0.0611). The cage of (1) approximates to a nido-icosahedron with a [graphic omitted] open face. Presumably the B-B connectivity in this face is hydrogen-bridged, but the bridge atom was not located in the crystallographic study. Thermolysis of (1) (100 °C toluene) releases one mol equiv. of H2 affording [9-H-9,10-(Et3P)2-7,8,9-C2PtB8H 9] (2), in which μ-H is lost and phosphine transfer from Pt to an adjacent facial B has occurred. Crystals are monoclinic, space group P21/c with a = 9.7813(16), b = 12.312(3) c = 20.519(3) Å, β = 99.053(16)°, and Z = 4. The structure was refined to R′ = 0.0578 (R′ = 0.0552) for 3 194 data measured at 293 K. The polyhedron of (2), formally a PtII species, shows distortion towards a closed octadecahedral architecture. The mechanism of the transformation of (1) into (2) is discussed in relation to the influence of the stereochemical changes involved.
|Number of pages||7|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 1983|
ASJC Scopus subject areas