Terephthalate bridged frameworks of Nd and Sm Phthalates

A hydrothermal reaction of terephthalic acid (1,4-benzenedicarboxylic acid, 1,4-BDC), M2O3 (M=Nd and Sm) 1,2-dicyanobenzene (1,2-DCB), produced a metal-organic coordination polymer of the formula, M2(H2O)4[(1,2-BDC)2(1,4-BDC)], (M=Nd and Sm). The phthalate anion, found in the final product was generated in situ during the synthesis by the hydrolysis of 1,2-DCB. The M atoms show differences in the coordination environments. The structure is built-up by the rare-earth phthalate layers cross-linked by the terephthalate anions giving rise to three-dimensional structure with one-dimensional rectangular channels. The bound water molecules project into these channels. Both the compounds exhibit photoluminescence.