Anion-assisted silver(I) coordination complexes from flexible unsymmetrical bis(pyridyl) ligands: Syntheses, structures and luminescent properties
作者:Zhu-Yan Zhang、Zhao-Peng Deng、Li-Hua Huo、Hui Zhao、Shan Gao
DOI:10.1016/j.poly.2013.04.041
日期:2013.8
The reaction of AgX (X = NO3- and ClO4-) salts, triphenylphosphine (PPh3) and four flexible unsymmetrical bis(pyridyl) ligands, namely N-(pyridin-2-ylmethyl)pyridin-2-amine (L1), N-(pyridin-3-ylmethyl) pyridin-3-amine (L2), N-(pyridin-2-ylmethyl)pyridin-3-amine (L3) and N-(pyridin-4-ylmethyl)pyridin3-amine (IA), leads to the formation of six complexes, [Ag-2(L1)(2)(ClO4)(2)](n) (1) [Ag-2(L2)(2)(ClO4)(2)](n)center dot n(CH3CN) (2), [Ag(L1)(NO3)](n) (3), [Ag(L2)(NO3)](n) (4), [Ag(L3)(NO3)(PPh3)](n) (5) and [Ag(L4)(NO3)(PPh3)](n) (6), which have been characterized by elemental analysis, IR, TG, PL, powder and single-crystal X-ray diffraction. In contrast to the chain structure of complexes 1 and 2, induced by the weakly coordinated perchlorate anion, the nitrate anion can coordinate to the Ag(I) cation in monodentate, chelating and even more intricate mu(2)-K-3 modes, thus defining dinuclear (complex 3), various chain motif (complexes 5 and 6) and layer structures (complex 4). The four ligands in the six complexes present diverse cis-cis, cis-trans and trans-trans conformations, which are responsible for the structural diversities and, together with the nature of the inorganic anions, the coordination spheres of the Ag(I) cations. Moreover, solid-state luminescent properties demonstrate that the emission intensities of the perchlorate-containing complexes are stronger than those of the nitrate-containing complexes. (C) 2013 Elsevier Ltd. All rights reserved.