Dual-Ligand-Oriented Design of Noncentrosymmetric Complexes with Nonlinear-Optical Activity

Abstract

When the N-and O-donor ligands are combined as coligands, two noncentrosymmetric (NCS) complexes of [Ni(pbdc)amine, p-H 2 bdc = 1,4-benzenedicarboxylic acid, and H 2 npdc = 2,6-naphthalenedicarboxylic acid] were achieved under solvothermal conditions. For both structures, N-donor ligands are responsible for the generation of a layered structure, while the O-donor ligands are hung on the layers and are responsible for enhancing the polarity, giving rise to the NCS structures. Because of the different connection modes between the metal centers and different carboxylate ligands (p-bdc 2− in 1 and npdc 2− in 2), 1 and 2 show some structural differences. The pbdc 2− ligands in 1 are suspended on the upper and lower sides of the [Ni(tipa)] n layers, while all of the npdc 2− ligands in 2 hang on one side of the [Ni(tipa)] n layers and point in the same direction, which makes the two NCS complexes show phase-matchable behavior with different second-harmonic-generation (SHG) responses of about 0.9 and 1.5 times that of KH 2 PO 4 (KDP), respectively. Theoretical studies reveal that charge transfers between Ni 2+ and carboxylate ligands make the dominant contribution to the optical properties. It is expected that a dual-ligand strategy may guide the design of novel superior-performing NCS complexes.

Two New Aluminoborates with 3D Porous-Layered Frameworks

“…Crystalline borates send out an enchanting charm in the sciences because of their multifarious structures and widespread applications in microporous and nonlinear optical (NLO) materials [1][2][3][4][5]. In 1975, the NLO properties of KB 5 O 8 •4H 2 O [6] were studied by C F. Dewey et al for the first time, pointing out the new research direction for the structure and properties of borates.…”