A novel 3D 10-fold interpenetrated homochiral coordination polymer: large spontaneous polarization, dielectric loss and emission studies

A novel 3D acentric coordination polymer, {[Cd-2(mpba)(2)(bpmp)(2)]center dot 2H(2)O} n (1) was obtained from hydrothermal reaction of the ligand H(2)mpba = (S)-4,4'-(2-methylpiprazine-1,4-diyl) bis(methylene) dibenzoic acid and a pyridine-based co-ligand, 4-bis(4-pyridinylmethyl) piperazine (bpmp) with Cd(NO3)(2) center dot 4H(2)O. The single crystal X-ray structure of 1 reveals that the complex comprises of a 4-connected dia topology with unusual 10 interpenetrating networks. Interestingly, complex 1 exhibits ferroelectric properties with an electric hysteresis loop, showing a remnant polarization (Pr) of ca. 2.01 mu C cm(-2) and a coercive field (Ec) of 11 kV cm(-1). Permittivity measurements of 1 reveal a high dielectric constant (a(r) similar to 80) and low dielectric loss (tan delta similar to 0.03), which suggests that it could be a useful material for high density data storage. Photoluminescence studies show that complex 1 exhibits emission peaks at around 392 nm in the solid state at room temperature.