Syntheses and characterizations of multidimensional metal-organic frameworks based on rings and 1D chains

Four novel multidimensional coordination polymers, {[Cd(3-PYD)(2)(H2O)].2H(2)O}(n) (1), [Pb(3-PYD)(2)](n) (2), {[Cu-1.5(3-PYD)(3)(H2O)].1.5H(2)O}(n) (3) and [Zn(3-PYD)(2)(H2O)(2)](n) (4), have been hydrothermally synthesized from 3-(3-pyridyl)acrylic acid (3-HPYD). In 1, 3-PYD in a head-to-head arranged fashion bridges Cd-II, generating a two-dimensional layer, which is further extended into a three-dimensional supramolecular network by hydrogen-bonding interactions. Compound 2 shows a two-dimensional wave-like layer that consists of {Pb(3-PYD)}(4) rings from head-to-tail arranged 3-PYD. Compound 3 is a twofold interpenetrating three-dimensional network consisting of {Cu(3-PYD)}(6), rings formed through the mixed head-to-head and head-to-tail arrangements of 3-PYD. However, 4 is a three-dimensional supramolecular framework constructed by one-dimensional zinc-3-PYD chains through hydrogen-bonding interactions. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)