Tripod‐Rhodium‐COD‐Komplexe: Synthese, Struktur, Dynamik und Katalyse

Abstract

Tripod Rhodium COD Complexes: Synthesis, Structure, Dynamics and Catalysis The reaction of the tripod ligands R′C(CH 2 PR 2 ) 3 ( 1a–c ) and X 2 POCH[CH 2 P(Ph) 2 ] 2 ( 2a–c ) with [Rh I (COD)Cl] 2 ] is investigated. It yields tripod rhodium COD complexes [( 1a–c )Rh I (COD)]Y ( 3a–c ) and [( 2a–c )Rh I (COD)]Y [ 4a–c ; Y = B(Ph) 4 , PF 6 ]. The tripod ligand is coordinated by all three donor groups in each case, irrespective of the different donor capabilities of the coordinating groups. The solid state structure of compounds 3a–c and 4a is determined by X‐ray analysis. The observed coordination polyhedra delineate the variation from the idealized trigonal bipyramide to an idealized quadratic pyramide. In solution the analysis of the NMR spectra shows a rapid intramolecular interconversion according to a turnstile pseudo rotation. The complexes 3a and 4a are found to be catalysts for the hydrogenation of prochiral olefines.