75361-88-5Relevant academic research and scientific papers
Preparation of heterobinuclear rhodium/palladium complexes using 2-(diphenylphosphino)pyridine as a connecting ligand
Farr, James P.,Olmstead, Marilyn M.,Balch, Alan L.
, p. 1229 - 1235 (2008/10/08)
The reaction between Rh(Ph2Ppy)2(CO)Cl and (1,5-cyclooctadiene)PdCl2 or between Pd(Ph2Ppy)2Cl2 and 1/2 molar equiv of Rh2(μ-Cl)2(CO)4 produces the head-to-tail complex RhPd(μ-Ph2Ppy)2(CO)Cl3 whose structure has been determined by X-ray crystallography. RhPd(Ph2Ppy)2(CO)Cl3 crystallizes in the space group Pc21b (bca setting of Pca21, No. 29) with cell dimensions (determined at 140 K) of a = 10.353 (5), b = 15.426 (7), and c = 21.219 (11) A?, Z = 4, and V = 3391 A?3. The structure was refined to a conventional R value of 0.039 by using 2018 significant reflections. The complex exhibits a six-coordinate Rh atom (ligand atoms are N, P, 2 Cl, Pd, C) and a planar Pd atom (ligand atoms are N, P, Cl, Rh) linked by a Rh-Pd single bond. Evidence for a strong trans effect of the metal-metal bond is found in the long axial Rh-Cl and Pd-Cl bonds. A mechanism of formation of RhPd(μ-Ph2Ppy)2(CO)Cl3 is proposed on the basis of the 31P{1H} NMR spectra of the reacting species at low temperature. Head-to-head (phosphorus trans to phosphorus at rhodium) and head-to-tail (phosphorus trans to nitrogen at rhodium) isomers of [RhPd(μ-Ph2PPy)2(CNCH3)2Cl 2]+ have been prepared by the reaction of [(CH3NC)2Rh(Ph2Ppy)2]+ with (PhCN)2PdCl2 or (1,5-cyclooctadiene)PdCl2, respectively. The thermal interconversion of these isomers is examined. The head-to-tail isomers are thermodynamically more stable.
