Huihui Zhang

Cadmium(II) supramolecular complexes constructed from a phenylbenzoxazole-based ligand: self-assembly, structural features and nonlinear optical properties

A new phenylbenzoxazole-based ligand bearing a pyridyl group (abbreviated as L) was designed and applied for self-assembly with corresponding cadmium(II) salts to generate four coordination complexes, namely, C19H15CdCl2N3O (1), C19H15Cd2Br2N3O (2), C40H38Cd2I4N6O4 (3) and C21H15CdN5OS2 (4). All the complexes 1–4 were fully characterized by single crystal X-ray diffraction. In 1 and 4, new supramolecular architectures are built mainly through synergistic effects of coordination bonds, hydrogen bonding interactions based on the anions and the benzoxazolyl nitrogen (oxygen) atom. There are more C–H⋯π and π–π stacking interactions constructing the higher dimensional structure in 2 and 3, respectively. In addition, in complex 3, we observe that CH3OH molecules are dispersed in the supramolecular structure and play a vital role in building the supramolecular structure. The nonlinear optical (NLO) properties of the complexes were investigated using the Z-scan technique, which showed that complexes 1 and 3 have obvious nonlinear absorption compared to ligand L.

A novel flurophore-cyano-carboxylic-Ag microhybrid: Enhanced two photon absorption for two-photon photothermal therapy of HeLa cancer cells by targeting mitochondria

In this study, a novel two-photon photothermal therapy (TP-PTT) agent based on an organic-metal microhybrid with surface Plasmon resonance (SPR) enhanced two-photon absorption (TPA) characteristic was designed and synthesized using a fluorescent cyano-carboxylic derivative 2-cyano-3-(9-ethyl-9H-carbazol-3-yl) -acrylic acid (abbreviated as CECZA) and silver nanoparticles through self-assembly process induced by the interfacial coordination interactions between the O/N atom of CECZA and Ag+ion at the surface of Ag nanoparticles. The coordination interactions caused electron transfer from the Ag nanoparticles to CECZA molecules at the excited state, resulting in a decreased fluorescence quantum yield. The interfacial coordination interactions also enhanced the nonlinear optical properties, including 13 times increase in the TPA cross-section (δ). The decreased fluorescence quantum yield and increased two photon absorption caused by the SPR effect led excellent two-photon photothermal conversion, which was beneficial for the TP-PTT effect on HeLa cancer cells.