HIGH-YIELD SYNTHESIS, MOLECULAR-STRUCTURE AND NMR-STUDIES OF THE 7-COORDINATE COMPLEX [WI2(CO)(3)(PET3)(2)]

The reaction of [WI2(CO)(3)(NCMe)(2)] with two equivalents of PEt3 in Et2O/CH2Cl2 gives the MeCN-displaced product [WI2(CO)(3)(PEt3)(2)] (1) in high yield. The crystallographically determined solid state struct ure of (1) shows the complex to be capped octahedral with a carbonyl l igand capping an octahedral face containing the two octahedral carbony ls and one PEt3 group. The other face contains the two iodo ligands tr ans to carbonyl groups, and the second PEt3 ligand trans to the first PEt3 group. The low temperature (-30 degrees C) C-13-{H-1}-n.m.r. spec trum of (1) correlates with the solid state structure, and the fluxion al properties of (1) have been investigated by VT P-31-{H-1}-n.m.r. sp ectroscopy.