A flexible polydentate bis(amidine)ligand LH_(2),LH_(2)={CH_(2)NH(tBu)CvN-2-(6-MePy)}_(2),operates as a molecular lock for various coinage metal fragments and forms the dinuclear complexes[LH_(2)(MCl)_(2)],M=Cu(1),Au(...A flexible polydentate bis(amidine)ligand LH_(2),LH_(2)={CH_(2)NH(tBu)CvN-2-(6-MePy)}_(2),operates as a molecular lock for various coinage metal fragments and forms the dinuclear complexes[LH_(2)(MCl)_(2)],M=Cu(1),Au(2),the coordination polymer[{(LH_(2))_(2)(py)_(2)(AgCl)_(3)}(py)_(3)]_(n)(3),and the dimesityl-digold complex[LH_(2)(AuMes)_(2)](4)by formal insertion of MR fragments(M=Cu,Ag,Au;R=Cl,Mes)into the N–H⋯N hydrogen bonds of LH_(2)in yields of 43–95%.Complexes 1,2,and 4 adopt C_(2)-symmetrical structures in the solid state featuring two interconnected 11-membered rings that are locked by two intramolecular N–H⋯R–M hydrogen bonds.QTAIM analyses of the computational geometry-optimized structures 1a,2a,and 4a reveal 13,11,and 22 additional bond critical points,respectively,all of which are related to weak intramolecular attractive interactions,predominantly representing dispersion forces,contributing to the conformational stabilization of the C_(2)-symmetrical stereoisomers in the solid state.Variable-temperature ^(1)H NMR spectroscopy in combination with DFT calculations indicate a dynamic conformational interconversion between two C_(2)-symmetrical ground state structures in solution(ΔG_(c)^(‡)=11.1–13.8 kcal mol^(-1)),which is accompanied by the formation of an intermediate possessing Cᵢsymmetry that retains the hydrogen bonds.展开更多
基金supported by the U.S.Department of Energy,Office of Energy Sciences Materials Sciences Division,under contract DE-AC02-05CH11231support for providing computing resources by the Advanced Computer Services at Kennesaw State University+1 种基金support by the Department of Chemistry and Biochemistry(New Faculty Startup Fund(#08020)as well as the College of Sciences and Mathematics(CSM)at Kennesaw State University(CSM Research Stimulus Program)by Aditya Birla Carbon(Birla Carbon Scholarship for O.U.T.)is acknowledged.This material is based upon work supported by the US National Science Foundation under grant CHE-1800332.
文摘A flexible polydentate bis(amidine)ligand LH_(2),LH_(2)={CH_(2)NH(tBu)CvN-2-(6-MePy)}_(2),operates as a molecular lock for various coinage metal fragments and forms the dinuclear complexes[LH_(2)(MCl)_(2)],M=Cu(1),Au(2),the coordination polymer[{(LH_(2))_(2)(py)_(2)(AgCl)_(3)}(py)_(3)]_(n)(3),and the dimesityl-digold complex[LH_(2)(AuMes)_(2)](4)by formal insertion of MR fragments(M=Cu,Ag,Au;R=Cl,Mes)into the N–H⋯N hydrogen bonds of LH_(2)in yields of 43–95%.Complexes 1,2,and 4 adopt C_(2)-symmetrical structures in the solid state featuring two interconnected 11-membered rings that are locked by two intramolecular N–H⋯R–M hydrogen bonds.QTAIM analyses of the computational geometry-optimized structures 1a,2a,and 4a reveal 13,11,and 22 additional bond critical points,respectively,all of which are related to weak intramolecular attractive interactions,predominantly representing dispersion forces,contributing to the conformational stabilization of the C_(2)-symmetrical stereoisomers in the solid state.Variable-temperature ^(1)H NMR spectroscopy in combination with DFT calculations indicate a dynamic conformational interconversion between two C_(2)-symmetrical ground state structures in solution(ΔG_(c)^(‡)=11.1–13.8 kcal mol^(-1)),which is accompanied by the formation of an intermediate possessing Cᵢsymmetry that retains the hydrogen bonds.
