(Hexamethylbenzene)ruthenium(II) complexes: synthesis and coordination chemistry of a novel tridentate ligand with an O,O,Cl-donor set

Abstract

Trimethyl phosphite reacts with (((C/sub 6/Me/sub 6/)RuCl/sub 2/)/sub 2/) in methanol to yield the cation ((C/sub 6/Me/sub 6/)RuCl(P(OCH/sub 3/)/sub 3/)/sub 2/)/sup +/, which has been isolated as a chloride or hexafluorophosphate salt. This cation undergoes a sequence of two Michaelis-Arbuzov type reactions to give the neutral complex and the L/sup -/ anion ((C/sub 6/Me/sub 6/)RuCl(P(O)(OCH/sub 3/)/sub 2/)/sub 2/)/sup -/. Attempts to isolate the anion in the form of its sodium salt NaL have led to products that always contain additional sodium iodide or sodium hexafluorophosphate. The free acid HL can be prepared by protonation from NaL or directly from the reaction of (((C/sub 6/Me/sub 6/)RuCl/sub 2/)/sub 2/) with dimethyl phosphonate, HP(O)(OCH/sub 3/)/sub 2/. L/sup -/ is a uninegative, potentially bidentate or tridentate ligand with an O,O,Cl donor set. It reacts with many transition-metal and main-group-metal ions, e.g. M/sup n+/ = Mg/sup 2 +/, Mn/sup 2 +/, Co/sup 2 +/, Ni/sup 2 +/, Cu/sup 2 +/, Zn/sup 2 +/, Cd/sup 2 +/, Pb/sup 2 +/, Al/sup 3 +/, or Fe/sup 3 +/, to give 2:1 complexes of the composition (ML/sub 2/)/sup (n-2)+/. The reactions of the complexes (((ring)MCl/sub 2/)/sub 2/), (ring)M = (C/sub 5/Me/sub 5/)Rh, (C/sub 6/Me/sub 6/)Ru, and (p-cymene)Ru, withmore » L/sup -/ lead to the cationic complexes ((C/sub 5/Me/sub 5/)RhL)/sup +/, ((C/sub 6/Me/sub 6/)RuL)/sup +/, and ((p-cymene)RuL)/sup +/, which have been isolated as hexafluorophosphate salts. HL oxidatively adds to the metal(0) complexes (Mo(CH/sub 3/CN)/sub 3/(CO)/sub 3/) and (W(DMF)/sub 3/(CO)/sub 3/) to yield metal hydride complexes of the composition (LM(CO)/sub 3/H). The molybdenum hydride is labile and rapidly gives HL and Mo(CO)/sub 6/ under an atmosphere of CO gas.« less