METAL-CENTERED COUPLING OF 2 CARBYNE LIGANDS TO FORM AN ALKYNE LIGAND

Bis(carbyne) complexes are discussed as key intermediates of numerous C - C coupling reactions of carbyne-complexes to alkyne complexes-an experimental detection of such intermediates has now been possible in the reaction of the cationic bis(carbene) complex 1 with bromine or ethyl isocyanide, which leads to the alkyne complexes 2 and 3 (see also Highlight on p. 1119). Thus, in principle, the prerequisites under which processes such as the catalytic hydrogenation of CO proceed, are now also better understood. Counter ion = BF4-. [GRAPHICS]