Synthesis, crystal structures, and photophysical properties of two novel lead(II)-SIP coordination polymers (NaH2SIP=5-sulfoisophthalic acid monosodium salt) containing tetranuclear lead(II) units

Two new Pb-II-SIP coordination polymers, {[Pb-4(OH)(2)(SIP)(2)(H2O)](H2PO)(5)}(n) (1) and [Pb-3(SIP)(2)(H2O)(5)](n) (2), have been synthesized by hydrothermal reactions of Pb(OH)(2) or Pb(NO3)(2) and 5-sulfoisophthalic acid monosodium. salt (NaH2SIP) at 160 degrees C, respectively. Single-crystal X-ray diffraction reveals that compound 1 has a 2D brick-wall-like architecture constructed from 1D tapes containing the basketlike tetranuclear [Pb-4(mu(3)-OH)(2)(COO)(2)], Compound 2 has a 2D-layered structure, which is constructed from a 1D-ladder structure composed of the cyclic [Pb-4(SIP)(2)(COO)(2)] grid with the four Pb atoms nearly coplanar. In the solid state, compound I exhibits blue photoluminescence with the maximum emission intensity at 436 nm upon excitation at 335 nm. Compound 2 shows phosphorescence with the maximum emission intensity at 603 run upon excitation at 426 nm. Both compounds have also been characterized by elemental analysis, IR spectra, TG analysis, and powder X-ray diffraction. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).