Three new five-coordinated mercury (II) dyes: Structure and enhanced two-photon absorption

摘要

A new donor-bridge-acceptor (D-π-A) type ligand (L: 4'-(4-[4-(imidazole)styryl]phenyl)-2,2':6',2"-terpyridine) with two-photon absorption and coordination ability was designed and synthesized. Self-assembly of the ligand with HgX2 (X = Cl, Br, I) yielded a series of new coordination complexes (Dyes 1-3) with five-coordinated mercury (II), which were characterized by single crystal X-ray diffraction determination. Solvent molecules and various weak interactions, including hydrogen bonds (C-H···N, C-H···X) and π-π interactions played significant roles in the final topological structures. Linear and nonlinear optical properties of the ligand and three dyes were described. Experimental results revealed that two-photon absorption cross sections of three dyes are extraordinary stronger than that of ligand.