Triangular [Ag3]3+ Complexes Supported by Picolyl‐Substituted N‐Heterocyclic Carbene Ligands

Abstract

AbstractA series of 12 picolyl‐containing NHC ligand precursors and their AgI salts are reported. The complexes [Ag3{Sim(CH2pyCl)2}3]X3 [2(PF6)3], [Ag3{Sim(CH2pyBr)2}3]X3 [3(PF6)3], [Ag3{Sim(CH2isoquin)2}3]X3 [4(PF6)3], [Ag3{5,6‐Cl2‐benzim(CH2py)2}3]X3 [6(BF4)3], [Ag3{5,6‐Me2‐benzim(CH2py)2}3]X3 [7(PF6)3], [Ag3(benzim{CH2py‐3,4‐(OMe)2}2)3]X3 [8(PF6)3], [Ag3{benzim(CH2py‐3,5‐Me2‐4‐OMe)2}3]X3 [9(PF6)3], [Ag3(5,6‐Me2‐benzim{CH2py‐3,4‐(OMe)2}2)3]X3 [10(PF6)3], [Ag3{5,6‐Me2‐benzim(CH2py‐3,5‐Me2‐4‐OMe)2}3]X3 [11(PF6)3], and [Ag3{5‐OMe‐benzim(CH2py)2}3]X3 [12(PF6)3] (X = PF6– or BF4–) each contain a central [Ag3]3+ core spanned by three NHC ligands. The optically pure [Ag3{(R,R)‐cyclohexylim(CH2py)2}3](PF6)3 [(R,R)‐5(PF6)3] adopts a different coordination mode. All complexes were characterized by NMR spectroscopy and HRMS. In addition, complexes 3(PF6), (R,R)‐5(PF6), 6(BF4), 7(PF6), and 8(PF6) were characterized by single‐crystal X‐ray diffraction and found to exhibit Ag–Ag distances of approximately 2.7 Å.