STRUCTURAL CHARACTERIZATION OF THE TRINUCLEAR CLUSTER COMPOUND [FE(CO)(4)(AUPPH(3))(2)] AND ISOLATION OF ITS PARENT ANION [FE(CO)(4)(AUPPH(3))](-)

A re-investigation of the reaction of Au(PPh(3))Cl with [Fe(CO)(4)](2- ) has shown that the [Fe(CO)(4)(AuPPh(3))](-) monoanion and [Fe(CO)(4) (AuPPh(3))(2)] are obtained in sequence by using a 1:1 and 2:1 molar r atio, respectively. The complex [Fe(CO)(4)(AuPPh(3))(2)] crystallizes in the monoclinic space group P2(1)/a, a=20.309(5), b=18.379(3), c=40. 737(6) Angstrom, beta=96.26(2)(0), Z=16, R=0.0526. There are four crys tallographically independent but chemically equivalent molecules in th e asymmetric unit. Each molecule consists of an Au2Fe triangle with th e two Au atoms bearing a PPh(3) ligand and the iron atom bound to four carbonyl groups. The feature of greatest interest in this molecule is the Au-Au interaction whose length is found in the range 2.897-2.941( 1) Angstrom, quite different from that quoted from a previous study (3 .028(1) Angstrom).