Modification of Wilkinson¡¯s catalyst with triphenyl phosphite: Synthesis, structure, ³¹P NMR and DFT study of trans-[RhCl(P(OPh)₃)(PPh₃)₂]

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• 作者：Ioannis Choinopoulos ; Ioannis Papageorgiou ; Silverio Coco ; Emmanuel Sim ; iras ; Spyros Koinis
• 关键词：Rhodium ; Phosphane ; Phosphite ; DFT ; Alkylation
• 刊名：Polyhedron
• 出版年：2012
• 出版时间：19 September, 2012
• 年：2012
• 卷：45
• 期：1
• 页码：255-261
• 全文大小：558 K

文摘

The complex trans-[RhCl(P(OPh)₃)(PPh₃)₂] (1) has been prepared and characterized by ³¹P NMR spectroscopy and single crystal X-ray crystallography. It was found that in the solid state there are two forms of complex 1 in the unit cell forming a cocrystal. DFT theoretical computations have confirmed the existence of the two forms and have provided evidence for the greater stability of 1 compared with Wilkinson¡¯s catalyst, [RhCl(PPh₃)₃] (2), in terms of the dissociation energy of the Rh-P(PPh₃) bonds. On the basis of the phosphorus chemical shifts, ¦Ä(), and the results of the theoretical computations, it is suggested that the Rh-P(PPh₃) bonding interactions are slightly enhanced in 1 compared with 2. A distinct difference between complexes 1 and 2, was found to be the catalytic activity of 1 in the alkylation of allyl acetate with sodium diethylmalonate, while 2 is almost catalytically inefficient.