Pyridine Complexes: Synthesis, Structure And Properties

In this thesis, hydrothermal reaction of different metal ions, Zn(II), Cu(II), Co(II), Ni(II), salts with 5-sulfoisophthalic acid monosodium salt (NaO3SC6H3-1,3-(COOH)2, NaH2SIP) and 1,10-phenanthroline (phen) led to eight new complexes. They were characterized by elemental analysis, IR, TGA and X-ray single-crystal diffraction, and fluorescent properties are also discussed.1. Eight new complexes: [Zn(phen)3]·2H2SIP·4H2O (1) [Zn(phen)2(H2O)2]·2H2SIP·2H2O (2) [Cu2(OH)(SIP)(phen)2]·6H2O (3) [Cu2(OH)(SIP)(phen)2]·H2O (4) [Cu(OH)(phen)2(SIP)]·(en)0.125·H2O (5) [CuCl(phen)2]·H2SIP·3H2O (6) [Co(phen)2(H2O)2]·2H2SIP·2H2O (7) [Ni(phen)3]-2H2SIP·3H2O (8)2. The results of the X-ray single-crystal structure analysis are as follows:(1) The crystal structure of 1,5,6 and 8 belong to triclinic system with P1 space group, while 2,3,4 and 7 crystallize in the monoclinic system with P21/n space group.(2) Complexes 1,2,6,7 and 8 are all zero-dimensional structures. In the structures of 1,2,6,7 and 8, the ligands H2SIPˉare all not coordinated with metal ions, engaging in the formation of hydrogen bond. Complexes 3,4 and 5 are two-dimensional layer structures. In 3,4 and 5, both phen ligand and SIP ligand are connected to central metal ions, and the SIP ligand serves as linkers to build two-dimensional structures. Moreover, Complexes 1-8 are assembled into 3D supramolecular architectures by hydrogen bonds, electrostatic force andπ-πinteractions.3. Thermalgravimetric analysis and photoluminescent properties:(1) TGA-DTA analysis exhibits that organic framework of compounds 1-8 start collapse until the temperature rising up to 330℃for 1,2,6,300℃for 3-5 and 350℃for 7-8, showing the higher thermal stability.(2) In the solid state compounds 1-2 exhibit intense fluorescence (λmax=394 nm for 1, 376 nm and 393 nm for 2) at excite bandλ1=320nm andλ2=280nm. The emission bands are assigned to be intraligand charge transfer of phen ligand. Complexes 3 and4 exhibit emission bands at 452nm and 486 nm, respectively, which may be attributed to metal-centred or ligand-to-metal charge transfer.