2D Chiral Ag(I) Complexes with A-π-- and D-π--Type Dicarboxylic Acid Ligands: Presenting Significant Differences in Nonlinear Optical Responses.

Three two-dimensional (2D) chiral Ag(I) complexes with formulas [Ag(L)(5-nipa)] (), [Ag(L)(5-nipa)] (), and {[Ag(L)(5-hipa)]·2HO} () were prepared through the reactions of AgO with enantiopure -monodentate N-donors (L/L) and different dicarboxylic acids bearing A (acceptor)-π-- and D (donor)-π--type structural features, where / = (-)/(+)-2-(4'-pyridyl)-4,5-pinene-pyridine, 5-Hnipa = 5-nitroisophthalic acid, and 5-Hhipa = 5-hydroxyisophthalic acid. A study of their nonlinear optical responses reveals that chiral and enantiomeric pairs with the A-π--type dicarboxylic acid ligand simultaneously display second- and third-harmonic generation (SHG and THG) responses, while chiral containing the D-π--type dicarboxylic acid ligand only exhibits a very strong THG response. The THG intensity of is 451 × α-SiO, being about 27 and 24 times larger than those of and , respectively.