Tuning silver(I) coordination architectures by ligands design: from dinuclear, trinuclear, to 1D and 3D frameworks

Abstract

In our efforts to tune the structures of Ag^I complexes by ligand modification, six structurally related ligands: 1,2-bis(triazol-1-ylmethyl)benzene (L¹), 1,3-bis(triazol-1-ylmethyl)benzene (L²), 1,4-bis(triazol-1-ylmethyl)benzene (L³), 1,3,5-tri(triazol-1-ylmethyl)-2,4,6-trimethylbenzene (L⁴), 1,4-bis[3-(2-pyridyl)-pyrazol-1-ylmethyl]naphthalene (L⁵), and 9,10-bis(benzimidazol-1-ylmethyl)anthracene (L⁶) have been designed and used to react with Ag^I salts to form six new complexes: {[Ag₂(L¹)₂](BF₄)₂(H₂O)} (1), [Ag₂(L²)(NO₃)₂]_n (2), [Ag(L³)(NO₃)]_n (3), {[Ag₃(L⁴)₂](SiF₆)_1.5(H₂O)_3.5} (4), {[Ag₂(L⁵)₂](NO₃)₂(H₂O)} (5), and {[Ag₂(L⁶)₂](NO₃)₂(CH₃OH)₂} (6). All the complexes have been structurally characterized by IR and X-ray diffraction. Structural analyses show that complexes 1, 5, and 6 possess dinuclear structures, which extend to infinite coordination networks linked by Ag⋯N, C–H⋯O, or π–π weak interactions. 2 is a 3D chiral coordination polymer with (10,3)-a topology, and 4 forms a trinuclear cage structure, which further connected by Ag⋯Ag weak interactions to form a 1D supramolecule, while 3 exhibits an infinite 1D chain structure. The structures of complexes 1–6 span from dinuclear, trinuclear, 1D, to 3D network, which indicates that ligands play important roles in the formation of such coordination architectures. Furthermore, the CD spectrum, thermal, and fluorescent properties of the chiral complex 2 have been investigated in the solid state.