Rhodium complexes containing 1-(4-pyridylmethylene)-4-alkoxyanilines as ligands: crystal structure of an unusual square-planar cluster of 64 electrons, Rh4(OOCCH3)4(CO)4(NC5H4CH:NC6H4OC14H29)4

Abstract

Rh(OCOCR3)(cod)Ln (1-6) and cis-Rh(OCOCR3)(CO)2Ln (7-12) (R = H, F; cod = 1,5-cycloctadiene; Ln = NC5H4CH=NC6H4OCnH 2n+1 with n = 2, 8, 14) complexes have been prepared by the reaction of the Ln ligands with the corresponding dimers [Rh(OOCCR3)(cod)]2 or [Rh(OOCCR3)(CO)2]2 (R = H, F). The cis-dicarbonyl compounds 7-12 decompose in dichloromethane solution to form square-planar clusters of 64 electrons, Rh4(OOCCH3)4(CO)4 Ln 4 (13-18). The molecular structure of Rh4(OOCCH3)4(CO)4L14 4 (15) has been determined by X-ray investigation. The complex is centrosymmetric, and the four rhodium atoms define a rectangle. Two alternant metal-metal bonds of the rectangle are bridged by two carbonyl groups; the other two remaining Rh-Rh bonds are bridged by two acetate groups. Each metal completes its coordination sphere with the pyridinic ligand NC5H4CH=NC6H4OC14H 29. Crystal data for 15: space group P1, a = 10.300 (1) Å, b = 11.166 (1) Å, c = 26.216 (3) Å; α = 89.29 (1)°, β = 88.68 (1)°, γ = 72.17 (1)°; 4491 reflections, R = 0.041, Rw = 0.041. The complexes [Rh4(OOCCH3)4(CO)4(py)4] (19, 20; R = H, F; py = pyridine) are also reported. © 1991 American Chemical Society.