Notizen: Neuartige basische Liganden für die homogenkatalytische Methanolcarbonylierung, XXVII [1] / Fluktuierendes Verhalten von Tris(Ether-Phosphan)-Ruthenium(II)-Komplexen / Novel Basic Ligands for the Homogenous Catalytic Carbonylation of Methanol, XXVII. Fluxional Behaviour of Tris(ether-phosphane) Ruthenium(II) Complexes

Abstract

Three equivalents of the ether-phosphane ligands 2a-c react with Cl2Ru(PPh3)3 (1) to give the complexes trans-Cl2Ru(P ̑O)(P∼O)2 (3a-c) (P∼O = η1-P-coordinated; P ̑O = η2-Ο,Ρ-coordinated). The hemilabile character of the P,O–ligands is becoming evident by the fluxional behaviour of 3 a-c. The coalescence temperatures in the AB part of their 31P{1H} NMR spectra are found at -10, 15 and -15 °C (AG* = 48, 53 and 47 kJ/mol). Because of steric effects, 3 a, in which the ether oxygen atom has the lowest basicity, and 3c, with the smallest ether substituent, show nearly the same dynamic properties.