The Schiff base pyridine-2-carboxaldehyde-4-aminoantipyrine(C17H16N4O 1) and its perchlorate(C17H17N4O·ClO4 2) have been prepared and characterized by elemental analysis,IR spectra and single-crystal X-ray crystallography analysis.Both 1 and 2 crystallize in the monoclinic system,space group P21/c.For 1,a = 8.6820(12),b = 24.934(3),c = 7.0064(10) ,β = 97.942(3)°,V = 1502.2(4) 3,Z = 4,Dc = 1.293 g/cm3,F(000) = 616,μ = 0.084 mm-1,the final R = 0.0592 and wR = 0.1244.For 2,a = 5.9302(2),b = 20.347(7),c = 14.663(6) ,β = 90.200(9)°,V = 1769.2(11) 3,Z = 4,Dc = 1.475 g/cm3,F(000) = 816,μ = 0.254 mm-1,the final R = 0.0533 and wR = 0.0819.As expected,both molecular structures of 1 and 2 adopt a trans configuration about the central C=N double bond.2 is an ionic compound with the protonation at N(1) of pyridine-2-carboxaldehyde-4-aminoantipyrine.
A novel tetranuclear zinc(II) coordination polymer [Zn4(o-bda)4(p-pbim)4]n 1 (p-pbim = 4-pyridylbenzimidazole, o-bda2- = o-phenylenediacetic acid dianion) has been synthe- sized by a hydrothermal method and characterized by elemental analysis, IR and X-ray single- crystal diffraction. The title complex crystallizes in monoclinic, space group of P21/n with a = 14.231(1), b = 16.257(1), c = 16.794(1) , β = 100.26(1)o, V = 3823.1(2) 3, Z = 8, Dc = 1.573 g/cm3, μ = 1.321 mm–1, F(000) = 1856, R = 0.0420 and wR = 0.111. The Zn(1) atom assumes a distorted trigonal bipyramidal geometry, involving three carboxyl O atoms from two different o-bda ligands and two N atoms from two p-pbim ligands. The Zn(2) atom is coordinated by two oxygens from two distinct bda2- anions and two nitrogen atoms from two p-pbim ligands to form a distorted tetrahedral geometry. The Zn(II) atoms are alternately interlinked by o-bda ligands in bis-monodentate or chelating-bidentate and monodentate modes into one-dimensional undulate chains along axis c with the adjacent Zn···Zn distances of 8.32 and 8.47 . Such neighboring chains are further extended into a 1D bi-chain structure with two different subrings A and B, which are 32- and 14-membered rings through interchain p-pbim ligands. There exists a 2D supramolecular network linked by intermolecular hydrogen-bonding interactions between the uncoordinated carboxylate O(4) atom or coordinated carboxylate O(7) atom and the uncoordinated imidazolyl N(2) and N(5) atoms with the O···N distances to be 2.695 and 2.807.
