Novel cadmium(II) adipate coordination polymers with structural transformation via oxalate ligand: Syntheses, structures and fluorescence properties

Two novel cadmium adipate coordination polymers [Cd{O2C(CH2)(4)CO2}{1,10-phen}](n) (1) and [Cd-2(C2O4)-{O2C(CH2)(4)CO2(OH2)(2)}{2,2'-bipy}].H2O (2) [adipic acid = HO2C(CH2)(4)CO2H] have been hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Crystallographic data for 1: monoclinic, C2/c, a = 16.186(3) Angstrom, b = 15.487(3) Angstrom, c = 14.052(3) Angstrom, beta = 112.73(3)degrees, Z = 8. Crystal data for 2: monoclinic, Cc, a = 23.448(5) Angstrom, b = 11.826(2) Angstrom, c = 8.3163(17) Angstrom, beta = 99.08(3)degrees, Z = 4. The structural analysis reveals that 1 forms a novel one-dimensional chain in which the binuclear Cd centers are linked by adipate anions. Compound 2 is the first example in which both a 2,2'-bipyligand and an oxalate group are found in the {M/ adipate) system. Compound 2 possesses one-dimensional sine- or cosine-type chains, which are alternately connected together by the oxalate group to form a three-dimensional framework. The structural determination reveals that the introduction of the oxalate ligand causes the dimensional transformation of the compounds. Compounds 1 and 2 show strong fluorescent properties at room temperature.