193901-74-5Relevant academic research and scientific papers
On the Coordination of Olefins and Secondary Amines at the Cationic [2,6-Bis(diphenyIphosphanylmethyl)pyridine]rhodium(I) Fragment [Rh(PNP)]+ - Synthesis and Characterization of [Rh(PNP)(L)]X (L = Ethylene, Styrene, HNR2; X = BF4, PF6, CF3so3)
Hahn, Christine,Sieler, Joachim,Taube, Rudolf
, p. 939 - 945 (2007/10/03)
The cationic rhodium(I) complexes [Rh(PNP)(C2H4)]X; X = BF4 (1a), PF6 (1b), CF3SO3 (1e) were prepared by addition of the tridentate ligand 2,6-bis(diphenylphosphanylmethyl)pyridine (PNP) to a solution of [Rh(C2H4)2(solv)2]X (solv = acetone or THF) under ethylene. The complexes were characterized by IR and 1H-, 13C-, and 31P-NMR spectroscopy. The coordination of two ethylene molecules at the [Rh(PNP)]+ fragment could be detected by dynamic proton resonance of a solution of la under free ethylene. The styrene complex [Rh(PNP)(styrene)]BF4 (4) was obtained by substitution of the ethylene from la with an excess of styrene. The π coordination of C2H4 and styrene in la and 4 respectively was confirmed by X-ray crystal structure analysis. The olefin complexes react with an excess of the secondary amine to give the corresponding amine complexes [Rh(PNP)(HNR2)]X; HNR2 = piperidine (5), HNMe2 (6), HNEt2 (7). Conversly, the amine could be released from the amine complexes with an excess of ethylene at low temperature by the formation of the ethylene complex 1. VCH Verlagsgesellschaft mbH,.
