THE PREPARATION AND CRYSTAL-STRUCTURE OF (DPPE)(CO)(3)RE-OC(O)O-RE(CO)(3)(DPPE)

The title compound is readily prepared from the rhenium carboxylate, ( dppe) (CO)(3)ReC(O)OCH3, by prolonged stirring of a solution of the ca rboxylate in benzene/H2O or THF/H2O. The reaction involves the unusual in situ conversion of Re-C bonds to Re-O bonds. The X-ray structure o f the title compound shows that the mu(2) eta(2)-carbonato ligand is p resent in the symmetrical syn, syn conformation in the solid state in contrast to the alternate syn, anti geometry reported for the related complex, (diars)(CO)(3)ReOC(O)ORe(CO)(3)(diars). (C) 1998 Elsevier Sci ence Ltd. All rights reserved.