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

Abstract

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.

New cationic coinage metal complexes featuring silyl group functionalized phosphine: syntheses, structures and catalytic studies in alkyne–azide cycloaddition reactions

“…The complex 2 displays a dimeric structure in the solid state with an ortho -silylated phosphine-supported Cu 2 (μ 2 -Cl) 2 core with a Cu⋯Cu separation of 3.00 Å. 25 It can be observed that simple triphenyl phosphine–CuCl attains a cubane structure in the solid state having tetrameric [PPh 3 CuCl] 4 nature with long Cu⋯Cu distances. 26 In contrast to this structure, complex 2 attains a dimeric nature in the solid state presumably due to the presence of a sterically bulky silyl group in the phosphine moiety, whereas the cationic complex 3 shows the formation of a tri-coordinate copper complex with two phosphine ligands and one acetonitrile coordination.…”

“…The dihedral angles between the two Cl–Cu–Cl in 2 are 97.28° (Cl1–Cu1–Cl2) and 98.15° (Cl1–Cu2–Cl2), which are consistent with the values reported in similar chloro-bridged copper complexes. 25…”

“…The complex 2 displays a dimeric structure in the solid state with an ortho-silylated phosphine-supported Cu 2 (μ 2 -Cl) 2 core with a Cu⋯Cu separation of 3.00 Å. 25 It can be observed that Scheme 2 Preparation of ortho-silylated phosphine-supported copper and silver complexes.…”

“…The complex 2 displays a dimeric structure in the solid state with an ortho-silylated phosphine-supported Cu 2 (μ 2 -Cl) 2 core with a Cu⋯Cu separation of 3.00 Å. 25 It can be observed that Scheme 2 Preparation of ortho-silylated phosphine-supported copper and silver complexes. simple triphenyl phosphine-CuCl attains a cubane structure in the solid state having tetrameric [PPh 3 CuCl] 4 nature with long Cu⋯Cu distances.…”

“…The dihedral angles between the two Cl-Cu-Cl in 2 are 97.28°(Cl1-Cu1-Cl2) and 98.15°(Cl1-Cu2-Cl2), which are consistent with the values reported in similar chloro-bridged copper complexes. 25 The silver complexes 4a-4c were also structurally characterized. Single crystals suitable for XRD analysis were grown by the vapor diffusion of dichloromethane solutions with n-hexane, and colorless crystals were used for the measurements.…”