Coordination Chemistry of the cyclo‐(P5tBu4)− Ion: Monomeric and Oligomeric Copper(I), Silver(I) and Gold(I) Complexes

Abstract

Abstract[Na{cyclo‐(P5tBu4)}] (1) reacts with [CuCl(PCyp3)2] (Cyp=cyclo‐C5H9) and [CuCl(PPh3)3] (1:1) to give the corresponding copper(I) complexes with a tetra‐tert‐butylcyclopentaphosphanide ligand, [Cu{cyclo‐ (P5tBu4)}(PCyp3)2] (2) and [Cu{cyclo‐(P5tBu4)}(PPh3)2] (3). The CuCl adduct of 2, [Cu2(μ‐Cl){cyclo‐(P5tBu4)}(PCyp3)2] (4), was obtained from the reaction of 1 with [CuCl(PCyp3)2] (1:2). Compounds 2 and 3 rearrange, even at −27 °C, to give [Cu4{cyclo‐ (P4tBu3)PtBu}4] (5), in which ring contraction of the [cyclo‐(P5tBu4)]− anion has occurred. The reaction of 1 with [AgCl(PCyp3)]4 or [AgCl(PPh3)2] (1:1) leads to the formation of [Ag4{cyclo‐(P4tBu3)PtBu}4] (6). Intermediates, which are most probably mononuclear, “[Ag{cyclo‐(P5tBu4)}(PR3)2]” (R=Cyp, Ph) could be detected in the reaction mixtures, but not isolated. Finally, the reaction of 1 with [AuCl(PCyp3)] (1:1) yielded [Au{cyclo‐(P5tBu4)}(PCyp3)] (7), whereas an inseparable mixture of [Au3{cyclo‐(P5tBu4)}3] (8) and [Au4{cyclo‐(P4tBu3)PtBu}4] (9) was obtained from the analogous reaction with [AuCl(PPh3)]. Complexes 3–7 were characterised by 31P NMR spectroscopy, and X‐ray crystal structures were determined for 3–9.