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)·3H(2)O. The post-synthesis transformation of HKUST-1 into Cu(BTC)·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.