Room temperature synthesis of a luminescent crystalline Cu-BTC coordination polymer and metal-organic framework

Synthesis of crystalline materials is elemental in the field of coordination chemistry towards optical applications. In the present work, coordination between copper and benzene-1,3,5-tricarboxylic acid (BTC) is controlled by adjusting the pH scale of the reaction mixture at room temperature to synthesize two crystalline structures: metal-organic framework HKUST-1 and coordination polymer Cu(BTC)center dot 3H(2)O. The post-synthesis transformation of HKUST-1 into Cu(BTC)center dot 3H(2)O is further demonstrated. Single crystals of both structures are studied by multi-laser Raman and luminescence spectroscopy. It is found that both crystals exhibit photoluminescence in the range of 700-900 cm(-1) within the optical gap of the bulk materials, which can be associated with crystallographic defects. This work gives impetus for the synthesis of large metal-organic crystals based on which optical properties can be studied in depth.

Automated summary

In this study, the synthesis of two crystalline structures by controlling the pH of the reaction mixture was demonstrated, along with the post-synthesis transformation from one structure to another. Both structures exhibited photoluminescence within the optical gap range, potentially due to crystallographic defects, providing a basis for further in-depth study of optical properties.