Larry W. Arndt

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)A, V 5024(3) A3, 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 OCFeCO edge and the other in a face at an AuFeAu angle of 69.0(1)°. The AuAu bond distance of 2.872(2)A is the smallest observed for analogous group 8 (R3PAu)2M(CO)4 complexes and is less than the AuAu distance of metallic gold. Acute FeAuAu angles in the Au2Fe triangle of 54.7(1), and 56.3(1)° further suggest a cluster formulation for the trimetallic.

Reactions of anionic transition metal carbonyl hydrides with electrophilic metal carbonyls: nucleophilic addition (hydride transfer) vs. electron transfer mechanisms

Abstract The relative reactivity of anionic transition metal carbonyl hydrides towards hydride transfer to monomeric metal carbonyls is consistent with an ionic route, generating, in the best-matched cases of electrophilic carbonyls (highest f CO or average v (CO)) and most nucleophilic hydrides (such as HW(CO) 4 P(OMe) 3 − ), metal formyls as sole product. With the metal carbonyl dimers Co 2 (CO) 8 , [(η 5 -C 5 H 5 )M(CO) 3 ] 2 (M = Mo, W), and Mn 2 (CO) 10 reductive cleavage to the respective anions occurs at rates which correlate with the nucleophilicity of the metal hydride, without observation of intermediate formyls. No reaction occurs with Re 2 (CO) 10 or [(η 5 -C 5 H 5 )Fe(CO) 2 ] 2 .