| The chemistry of organic-inorganic coordination polymers has recently become area of increasing interest. Self-assembly of organic ligands and inorganic metal ions is one of the most efficient and widely used approaches for the construction of organic-inorganic composite materials. Recently, remarkable progress has been made in the area of molecular inorganic-organic hybrid compounds. The synthesis and characterization of infinite one-, two- and three-dimensional networks have been an area of rapid growth. In this thesis, a series of novel semi-rigid bent 1, 3, 4-Oxadiazole bridging ligands were synthesized. The coordination chemistry of these novel ligands with transition metal ions was investigated by solution and hydrothermal reactions. Totally 38 new coordination polymers were prepared by solution and hydrothermal reactions and fully characterized by IR, elemental analysis, powder-XRD and single-crystal X-ray diffraction. The solid state luminescent properties, thermal analysis, NLO activity and the electrical conductive properties of selected polymeric compounds were investigated.1. The coordination chemistry based on semi-rigid bent 1, 3, 4-Oxadiazole bridging ligands with transition metal ions by solution and hydrothermal reactions.(I) The coordination chemistry of the 1, 3, 4-Oxadiazole-bridging ligands L1 and L2 with inorganic salts M(II)(M = Cd(II), Cu(II), Co(II), Zn(II)) has been investigated. Six new coordination polymers, namely {[Cd(L1)2](NO3)2} (1), {[Cu(L1)2](NO3)2} (2), {[Cu(L1)2]Cl2·2(H2O)} (3), {Co(L2)2} (4), {Zn(L2)2} (5), {Co(L2)2H2O} (6) were synthesized based on them, respectively. Their single crystal structures were investigated.(II) The coordination chemistry of the 1, 3, 4-Oxadiazole-bridging ligands L3 and L4 with inorganic salts M(II)(M = Co(II), Ni(II), Cu(II), Hg(II), Cd(II), Zn(II)) has been investigated. Twelve new coordination polymers, namely {Hg(L3)Cl2} (7), {[Cu(L3)2(H2O)](ClO4)2·2(H2O)} (8), {[Ni(L3)2]Cl2·2(CHCl3)} (9), {[Co(L3)]Cl2}·1.50(CH2Cl2} (10), [Co2(L3)2]Cl4·4CHCl3·CH3OH} (11), {Co(L3)Cl2} (12), {[Co(L4)]·0.5(H2O)} (13), {Cd(L4)2·2.5(H2O)} (14), {[Cd(L4)]·0.5(H2O)} (15), {Cd(L4)2(H2O)} (16), {Zn(L4)2·2H2O} (17), {Zn2(L4)4·1.5H2O} (18) were synthesized based on them, respectively. Their single crystal structures were investigated.(III) The coordination chemistry of the 1, 3, 4-Oxadiazole-bridging ligands L5 and L6 with inorganic salts M(II)(M = Co(II), Ni(II), Cu(II), Hg(II), Cd(II), Zn(II)) has been investigated. Ten new coordination polymers, namely {Cu(L5)2(SCN)2} (19), {[Cd(L5)2(SCN)2]} (20), {[Cd(L5)](SCN)2} (21), {[Cu(L5)2](NO3)2·4(H2O)} (22), {[Co(L5)2](NO3)2·2(H2O)} (23), {[Cu(L5)2]Cl2·2(H2O)} (24), {[Co(L5)2]Cl2·THF} (25), {[Co(L5)2]Cl2·THF} (26), {[Cd(L5)2]Cl2·2(H2O)} (27), {[Cu(L6)2](ClO4)2} (28) were synthesized based on them, respectively. Their single crystal structures were investigated.(IV) The coordination chemistry of the 1, 3, 4-Oxadiazole-bridging ligands L7 and L8 with inorganic salts M(II)(M = Co(II), Hg(II), Cd(II), Zn(II)), Cu(I)) has been investigated Ten new coordination polymers, namely {[Co(L7)]Cl2·CHCl3} (29), {Cd(L7)Cl2·CHCl3} (30), {[Hg2(L7)2]I4·CHCl3} (31), {[Hg(L7)]Cl2·CHCl3} (32), {[Co(L7)](CH3COOH)2·CH3OH} (33), {[Co(L7)](SCN)2·CHCl3} (34), {[Cd(L7)]I2} (35), {[Co(L7)]Cl2} (36), {[Cu4(L7)2]Cl4} (37), {[Zn(L8)]·H2O} (38) were synthesized based on them, respectively. Their single crystal structures were investigated.2. The NLO activity of selected coordination compounds were investigated. The primary result indicates that these compounds are SHG-active and could be considered as the potential NLO-active materials.3. The electrical conductive properties of selected coordination compounds were investigated. The primary result indicates that these compounds behave as typical semi-conductors.4. The luminescent ptoperties of ligand and their polymeric compounds were investigated in the solid state. The results indicate that emission colors of the oxadiazole-containing organic spacers were affected by their incorporation into metal-containing coordination compounds. This can be an efficient method for obtaining new types of electroluminescent materials.5. The thermal analysis of polymeric compounds were investigated. The results indicate that these inorganic-organic coordination polymers are highly stable. And selected coordination compounds can be stable up to 300oC.The results reported herein demonstrate that the use of semi-rigid bent 1, 3, 4-Oxadiazole bridging ligands as precursors to bind transition metal ions by solution and hydrothermal reactions, is in fact a new and efficient approach for synthesis of novel supramolecular networks with interesting physical properties.
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