Influence of coordination modes of 4,4′-bipyridine and secondary bonds on the structural assembles: Syntheses, crystal structures and properties of two lead(II) 3-sulfobenzoate coordination polymers

Two novel structures, {[Pb(3-sb)(4,4′-bipy)0.5](H2O)}n (1) together with the previously reported complex {[Pb(3-sb)(H2O)2](4,4′-bipy)}n (2), where 3-sb is 3-sulfobenzoate dianion and 4,4′-bipy is 4,4′-bipyridine, were synthesized and characterized by IR, elemental analyses, TGA, powder X-ray, fluorescent and single-crystal X-ray analyses. The highly ordered 2-D structure of 2 exists as π–π stacking and hydrogen-bonding interactions, while complex 1 is a 3-D network with 2-D interpenetration layers without π–π and hydrogen-bonding interactions and with abundant secondary bonding interactions. Therefore, complex 1 has thermally more stable structure than that of complex 2, and water molecules can be removed and re-combined in complex 1.