Carbene complexes of cycloplatinated 1H-indole-1-methyl-2-(2 '-pyridine). The crystal and molecular structure of sigma-{Pt[1H-indole-1-methyl-2-(2 '-pyridinyl-C-3,N '](DMSO)Cl} and of sigma-{Pt[1H-indole-1-methyl-2-(2 '-pyridinyl-C-3,N ')][= C(OCH2CH3)(CH2C6H5)]Cl}

Reaction of 1-methyl-2-(2'-pyridinyl)-1H-indole (1) with PtCl2(DMSO)(2) (DM SO = dimethylsulfoxide) gave the cycloplatinated product 2; X-ray structure determination of 2 showed a metallation to platinum via the C3 carbon of t he indole nucleus, which is chelated to the metal via the pyridine nitrogen atom. Compound 2 reacts with neutral ligands such as CO, Bu'NC, styrene an d phenylacetylene, to give compounds 3-6 respectively, where DMSO is replac ed by the neutral ligands. The phenylacetylene derivative 6 reacts with eth anol to give the carbene complex 7, whose X-ray structure has been determin ed. Related carbene complexes with other alcohols and other acetylenic deri vatives have also been synthesised. (C) 2000 Elsevier Science S.A. All righ ts reserved.