New mixed-ligand isocyanide diphosphine ruthenium(II) derivatives. Synthesis of a potential metal-containing tetradentate ligand

Abstract

Reaction of trans-[RuCl₂(CNPh)₄] with an excess of Ph₂PCH₂PPh₂(dppm) in refluxing toluene gave two complexes cis,cis,trans-[RuCl₂(CNPh)₂(dppm-P)₂]1 and mer-[RuCl(CNPh)₃(dppm)]Cl 2a; whereas in the reaction of trans-[RuCl₂(CNBu^t)₄] with dppm under the same conditions only mer-[RuCl-(CNBu^t)₃(dppm)]Cl 2b was obtained. Complex 1 reacted with TIPF₆ in CH₂Cl₂ to give [RuCl(CNPh)₂(dppm)(dppm-P)]PF₆3, a cationic complex containing both a monodentate and a chelated dppm ligand. Complex 1 is remarkable in having two monohapto dppm ligands and can be used in the synthesis of heterometallic species. Thus, treatment of 1 with AgClO₄ or HgCl₂ gave the heterometallic complex [(dppm)(PhNC)₂ClRu(µ-dppm)AgCl]ClO₄4 or [{(dppm)(PhNC)₂ClRu(µ-dppm)HgCl₂}₂]Cl₂5 respectively.