Copper and Silver Complexes of N-Heterocyclic Carbene-Parent Phosphinidene Adducts

The reactions of the N-heterocyclic carbene-parent phosphinidene adducts (IMes)PH (1 a) and (IDipp)PH (1 b) with one equivalent of copper(I) or silver(I) chloride afforded the monometallic complexes [{(IMes)PH}MCl] (2 a, M=Cu; 2 b, M=Ag) and [{(IDipp)PH}MCl] (3 a, M=Cu; 3 b, M=Ag). Single-crystal X-ray diffraction analyis provided evidence for a higher tendency of the (IMes)PH ligand to form polynuclear structures with bridging NHC-phosphinidene ligands in the solid state, while the larger (IDipp)PH ligand afforded mononuclear complexes. The reactions of 1 a and 1 b with two equivalents of CuCl provided evidence for the formation of the bimetallic complexes [{(NHC)PH}(CuCl)(2)] (4 a, NHC=IMes; 4 b, NHC=IDipp), but their isolation in pure form was not possible because of their considerable instability in solution.

Automated summary

The reaction of N-heterocyclic carbene-parent phosphinidene adducts with copper(I) or silver(I) chloride resulted in the formation of monometallic complexes. Single-crystal X-ray diffraction analysis revealed that the (IMes)PH ligand tends to form polynuclear structures, while the larger (IDipp)PH ligand forms mononuclear complexes. The bimetallic complexes could not be isolated in pure form due to their instability in solution.