Neutral and cationic diphenylphosphine and diphenylphosphido derivatives of a trinuclear ruthenium carbonyl cluster containing a bridging 1-azavinylidene ligand

Abstract

The synthesis and some reactivity of a number of neutral and cationic diphenylphosphine and/or diphenylphosphido derivatives of the 1-azavinylidene cluster compound [Ru 3( μ-H)( μ-N=CPh 2)(CO) 10] ( 1) are described. Compound 1 reacts with diphenylphosphine to give the substituted derivative [Ru 3( μ-H)( μ-N=CPh 2)(PPh 2H)(CO) 9] ( 2). Thermolysis of compound 2 leads to the dihydrido- μ-phosphido derivative [Ru 3( μ-H) 2( μ-N=CPh 2)( μ-PPh 2)(CO) 8] ( 3), which on exposure to carbon monoxide is converted into the non-hydridic derivative [Ru 3( μ-N=CPh 2)( μ-PPh 2)(CO) 9] ( 4). Treatment of complex 3 with diphenylphosphine gives [Ru 3( μ-H) 2( μ-N=CPh 2)( μ-PPh 2)(PPh 2H)(CO) 7] (5). Compounds 2, 4, and 5 undergo protonation with HBF 4 · OEt 2 to give the cationic derivatives [Ru 3( μ-H) 2( μ-N=CPh 2)(PPh 2H)(CO) 9][BF 4] ( 8), [Ru 3( μ-H)( μ-N=CPh 2)( μ-PPh 2)(CO) 9][BF 4] ( 9), and [Ru 3( μ-H) 3( μ-N=CPh 2)( μ-PPh 2)(PPh 2H)(CO) 7][BF 4] ( 10), respectively. The syntheses of these cationic complexes represent rare examples in which the protonation of neutral phosphido-bridged compounds has been achieved.