Vitrification and Luminescence Properties of Metal-Organic Complexes

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), inspite 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 (similar to 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).

Automated summary

In this study, MOC crystals with accessible liquid states and low mass loss at melting temperatures were synthesized, and new hybrid glasses and fibers were obtained through rapid quenching. It was found that halide ions played a crucial role in the melting thermodynamics of the synthesized crystals, and a highly transparent and efficient luminescent hybrid glass was discovered, which shows promise for photonic applications.