Tuning the Framework Formation of Silver(I) Complexes with Flexible Bis(benzothiazol-2-ylsulfanyl)alkanes by Varying the Ligand Spacers and Counteranions

Abstract

In our efforts to systematically investigate the influences of terminal groups, ligand spacers, and counteranions on the framework formations of the AgI complexes with thioether ligands, four structurally related flexible N-containing heterocyclic thioethers, bis(benzothiazol-2-ylsulfanyl)methane (L1), 1,3-bis(benzothiazol-2-ylsulfanyl)propane (L2), 1,4-bis(benzothiazol-2-ylsulfanyl)butane (L3) and 1,5-bis(benzothiazol-2-ylsulfanyl)pentane (L4), and seven new AgI complexes of these ligands, [AgL1(NO3)]∞ 1, {[AgL1](ClO4)(H2O)}2 2, {[AgL2(NO3)](CHCl3)}2 3, {[AgL3](ClO4)}∞ 4, {[AgL3](BF4)}∞ 5, {[AgL4(NO3)]CHCl3}2 6, and {[AgL4(ClO4)]2}∞ 7, have been synthesized and characterized. The crystal structures of these complexes show that all the other complexes except 4 and 5 form ligand-supported dinuclear clusters, and in 1 and 7 the dinuclear cluster units are further linked by anions to form 1D chains, and complexes 4 and 5 exhibit 1D zigzag chain structures. Furthermore, these ligands coordinate to AgI ions in N,N-bidentate rather than N,N,S-tridentate or N,N,S,S-tetradentate modes, and the AgI centers adopt 2- to 5-coordination geometries with different coordination environments. In 1, 2, 3, 6, and 7, the coordination modes of the ligands are not sensitive to the changes of the spacers, and the terminal groups seem to be the determining factor in controlling the coordination modes of the ligands. However, the differences of the -(CH2)n- ligand spacers also contribute to the geometrical differences of the dinuclear units. The structural differences between 1 and 2, 6, and 7 show the influences of the counteranions on the coordination geometries of AgI ions and the structures of the complexes.