Syntheses, structures and photoluminescence of two 3D pillared metal-organic frameworks with unique (411·64)(410·65) topology based on two kinds of topologically nonequivalent nodes

The hydrothermal reactions of Sr(NO3)2 or BaCl2 with 5-sulfoisophthalic acid (H3SIP) in the presence of triethylamine yielded two novel 3D coordination polymers [M(HSIP)(H2O)]n (M = Sr (1) and Ba (2)). Single-crystal X-ray analyses revealed that the two compounds are isostructural. The [M(HSIP)(H2O)]n compound displays a 3D pillared framework featuring a 2D metal sulfonate–carboxylate layer, and has two kinds of topologically nonequivalent six-connected nodes based on Sr ions and HSIP ligands with a rare (411·64)(410·65) topology. In the solid state, both 1 and 2 show blue photoluminescence with the maximum emission intensities at 445 and 439 nm upon excitation at 325 and 328 nm, respectively.