THE SYNTHESIS AND MOLECULAR-STRUCTURE OF (PH3PAU)2FE(CO)3P(OET)3 - A TRIANGULAR AU2FE CLUSTER

Reaction of salts of HFe(CO)3PR3- (R = OMe, OEt, OPh, Me, Ph) with Ph3PAuCl leads to quantitative partitioning into H2Fe(CO)3PR3 and (Ph3PAu)2 Fe(CO)3PR3. The complex (Ph3PAu)2Fe(CO)3P(OEt)3 · Et2O crystallized in the monoclinic space group P21/n, with a 10.385 (3), b 35.452(10), c 13.648(6)Å, V 5024(3) Å3, β 91.15(3)°, and Z = 4. The coordination geometry about Fe is that of a distorted Fe(CO)3PR3 tetrahedron bicapped with Ph3PAu moieties; one along a OCFeCO edge and the other in a face at an AuFeAu angle of 69.0(1)°. The AuAu bond distance of 2.872(2)Å is the smallest observed for analogous group 8 (R3PAu)2M(CO)4 complexes and is less than the AuAu distance of metallic gold. Acute FeAuAu angles in the Au2Fe triangle of 54.7(1), and 56.3(1)° further suggest a cluster formulation for the trimetallic. © 1990.