ALKYNE COMPLEXES OF COPPER(I) (1,1,1,5,5,5-HEXAFLUORO-2,4-PENTANEDIONATO) - SYNTHESES AND CHARACTERIZATION OF (ETA(2)-BIS(TRIMETHYLSILYL)ACETYLENE) COPPER(I) (HFAC), (MU-ETA(2)-BIS(TRIMETHYLSILYL)ACETYLENE) BIS(COPPER(I) (HFAC)) AND A SERIES OF (ETA(2)-ALKYNE) CU(HFAC) COMPLEXES

The reaction of Cu2O with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (Hhf ac) in the presence of alkynes results in the formation of (eta(2)-alk yne) Cu(hfac), When using bis(trimethylsilyl)acetylene (BTMSA), both a mononuclear compound BTMSACu(hfac) (1) and a dinuclear complex BTMSA( Cu(hfac))(2) (2) can be isolated; each complex was characterized by X- ray crystallography, IR, H-1 and C-13 NMR spectroscopies. In 1, the BT MSA ligand is eta(2) bonded parallel to the Cu(beta-diketonate) plane, the trimethylsilyl groups are cis bent away from copper with small an gles of deformation (theta(CCSi) = 157 and 171 degrees) and the C=C bo nd distance is 1.17 Angstrom. In 2, two BTMSACu(hfac) planes with a di hedral angle of 105.8 degrees are observed. The intramolecular Cu-Cu d istance is only 2.800 Angstrom and the central axis of BTMSA is situat ed perpendicular to the Cu-Cu vector. A series of eta(2)-alkyne Cu(hfa c) were synthesized and characterized by NMR and IR spectroscopy.