Vitrification and Luminescence Properties of Metal–Organic Complexes

• Published in: ACS materials letters Vol. 4; no. 12; pp. 2613 - 2621
• Main Authors: Ali, Mohamed. A., Liu, Xiaofeng, Xu, Beibei, Li, Yang, Mohamed, Moushira. A., Yue, Yuanzheng, Qiu, Jianrong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05-12-2022
• ISSN: 2639-4979; 2639-4979
• DOI: 10.1021/acsmaterialslett.2c00357

In coordination chemistry, crystalline inorganic–organic hybrids are new functional materials that combine inorganic and organic chemistry. Liquid and glass formation have been observed in hybrid materials (e.g., metal–organic frameworks and coordination polymers), while a little attention has been paid to the vitrification of metal–organic complexes (MOCs), in spite of their various functionalities. In this letter, we synthesize MOC crystals (i.e., MX2(HbIm)2, M = Zn and Co; X = Cl, Br, and I; HbIm = benzimidazole) that have accessible liquid states with low mass loss at their melting temperatures. After quenching the MX2(HbIm)2 liquids, a series of new hybrid glasses and fibers are obtained with large size. Based on the structural and calorimetry analysis, we found that the halide ions play a crucial role in the melting thermodynamics of the as-synthesized MOC crystals. Surprisingly, the ZnX2(HbIm)2 glasses are highly transparent in the visible and near-infrared regions (∼89%) and show an efficient luminescence after the network is doped by organic dyes. The luminescence efficiency of the dye-doped MOC glass is thickness-dependent. Our findings make the MX2(HbIm)2-based hybrid glass a promising material for photonic applications (e.g., lighting and lasers).