FIRST EXAMPLES OF ACYLGOLD(I) COMPLEXES RCOAUPPH3 (R = ME, N-BU, T-BU, PH) TRAPPED AS OXYGEN COORDINATED LIGANDS L AT ONE OF RHENIUM ATOMS IN RE-2(MU-PPH2)(2)(CO)(7)(AX-L)

In chloroform solution, the title compounds have been generated at roo m temperature from 1 equiv. ClAuPPh3 and the lithium salts of the type Li[Re-2(mu-PPh2)(2)(CO)(7)(ax-C(R)O)] (R = alkyl and aryl residues). The selective formation of such monoanions in the lithium salts from R e-2(mu-PPh2)(2)(CO)(8) and 1 equiv. LiR in THF solution at -90 degrees C runs quantitatively. All the products obtained were characterized b y means of H-1 NMR, P-31 NMR and upsilon(CO) IR measurements. The mole cular structure of Re-2(mu-PPh2)(2)(CO)(7)(ax-n-BuCOAuPPh3), which has been determined by a single-crystal X-ray analysis, is presented. Suc h examinations ascertain the first acylgold(I) complexes which are tra pped as O-coordinated ligand L in Re-2(mu-PPh2)(2)(CO)(7)(ax-L). The u nusal transfer of an acyl group from a rhenium to a gold center is dis cussed. Up to now, our attempts to gain the free acylgold(I) organyls remained unsuccessful. (C) 1998 Elsevier Science S.A.