Showing papers by "Martin Murray published in 1982"

Chemistry of di- and tri-metal complexes with bridging carbene or carbyne ligands. Part 11. Some reactions of the compound [PtW{µ-C(OMe)C6H4Me-4}(CO)5(η-C8H12)] and the crystal structure of one isomer of [Pt3{µ-C(OMe)C6H4Me-4}3(CO)3]

Abstract: The compound [(OC)5[graphic omitted]t(cod)](cod = cyclo-octa-1,5-diene) reacts with PMe3, dppe (Ph2PCH2CH2PPh2), and pdma [C6H4(AsMe2)2–1,2] to give the bis-phosphine complexes [(OC)5[graphic omitted]tL2][L2=(PMe3)2, dppe, or pdma] in which the dimetallacyclopropane rings are preserved. In contrast, reactions with CO or CNBut afford triplatinum compounds [Pt3{µ-C(OMe)C6H4Me-4}3L3](L = CO or CNBut)(two isomers). For L = CO the isomers were separated, and a single-crystal X-ray diffraction study was carried out on one species thereby establishing its configuration. The crystals are orthorhombic, space group P212121, Z= 4, in a unit cell with lattice parameters a= 11.085(2), b= 15.554(3), and c= 18.733(5)A. The structure has been refined to R 0.046 (R′ 0.045) for 2 699 reflections to 2θ⩽ 50°[Mo-KαX-radiation] collected at room temperature. The molecule consists of an essentially equilateral triangle of platinum atoms [mean Pt–Pt 2.624(1)A], each metal atom carrying a terminally bonded CO ligand [mean Pt–CO 1.82(3)A]. The three metal–metal vectors are bridged by C(OMe)C6H4Me ligands [mean Pt–µ-C 2.15(3)A], such that the plane defined by the metal atoms and the three ligated carbon atoms is perpendicular to the planes of these µ-C atoms and the O and C atoms to which they are bonded. Moreover, two of these groups have the same orientation with respect to the Pt3 plane whilst the third is inverted. The 195Pt n.m.r. spectrum of this ‘ asymmetric ’ isomer has been measured and analysed. Spectroscopic data for all the new compounds are given.