SYNTHESIS, STRUCTURE AND REACTIVITY OF ACETYLENIC CO-2(CO)(6) PYRYLIUM-SALTS - ELECTRONIC INFLUENCE OF THE CO-2(CO)(6) ACETYLENIC FRAGMENT

The formation of new pyrylium salts bearing in the gamma position an a cetylenic Co-2(CO)(6) fragment is described. X-ray analysis showed tha t the gamma carbon of the pyrylium ring does not interact with a cobal t atom. However, IR values, relating to the carbonyl stretching band, suggested that a part of the positive charge is delocalized on the clu ster core. Finally, the reactivity of these cationic complexes towards nucleophiles is reported. (C) 1997 Elsevier Science S.A.