Hydrothermal Synthesis, Characterization And Dye Catalytic Degradation Of Transition Metal Complexes With 1,10-phenanthroline Derivatives

With the rapid development of modern society, materials with special functions, such as optical and electrical properties, magnetic properties and photocatalytic properties, have become a hot topic of scientific research. Complex, a kind of meaterial with not only great variety of bond and novel spatial structure but the special optical, electric, magnetic and catalytic properties, especially the feasibility of application in the photocatalytic degradation of environmental pollution, has been received much attention. The transition metal complexes possess the merits of both metal and polymer and have wide potential in clean power source, smart response materials and high-performance devices. The airtight conditions of hydrothermal synthesis are in favor of processing those harmful and toxic reaction, which can reduce the environmental pollution as much as possible and the entire experimental process belongs to the one of green environmental protection. In this paper, seventeen novel transition metal complexes were prepared by hydrothermal synthesis method. Their structures were characterized by X-ray crystal diffraction. The optical, magnetic, and photocatalytic properties of these complexes were investigated.Two aspects of research work in this paper is shown in the following: Firstly, ten new compounds, namely [Cd4(MOPIP)12]·(H2O)9 (1), [Mn2(MOPIP)6]·(H2O)6 (2), [Cu(MOPIP)2]-(OH)2 (3), [Ni(MOPIP)3]·H2O·C6H5O3 (4), [Ag2(MOPIP)(HMOPIP)]n·nNO3·1.5n H2O (5), [Cr(MOPIP)2]Cl (6), [Co(MOPIP)(HMOPIP)2](OH)2·3H2O (7),[Cu2(MOPIP)2]n (8), [Zr(MOPIP)3]-(OH)·3H2O (9), [Co(AIP)(HAIP)2](OH)2 (10), based on 1,10-phenanthroline derivatives (2-(4-methoxyphenyl) -1H-imidazo[4,5-f][1,10] phenanthroline, MOPIP and 2-(9-anthryl) -1H-imidazo[4,5-f][1,10] phenanthroline, AIP) were synthesized under hydrothermal conditions. In (1), (2), (4), (7), (9) and (10), every metal ion is hexa-coordinated with six nitrogen atoms from three different MOPIP ligands in the crystal structure, showing a slightly distorted octahedral geometry. In the complexes (3) and (6), the each center ion is coordinated with four nitrogen atoms from two different MOPIP molecules, showing tetrahedronal structure. The complexes (5) and (8) are one-dimensional chains. In (5) and (8), the each center ion is three-coordinated with three nitrogen atoms from different HMOPIP and MOPIP ligands, assuming a slightly distorted triangle, respectively. The quantum chemical calculation and analysis of the natural bond orbital (NBO) of (3) and (6) was performed by using the Gaussia 03 Program. The photocatalytic activity of complexes (2), (3) and (4) was investigated by degradation of dye, respectively. The results show that the catalytic degradation rate of complex (3) is much higher than the others. Thus, complex (3) has the potential application in wastewater treatment.Secondly, seven new compounds, viz. [Ni(1,2-BDC)(Medpq)(H2O)3] (11), [Cd(1,4-BDC)(Medpq)·H2O]n (12), [Co(1,4-BDC)(Medpq)·H2O]n (13), [Co(Medpq)(PDC)·H2O]2n·2.4nH2O (14), [Cd(Medpq)(PDC)·H2O] n·nH2O(15),{[Mn(1,2-BDC)(Medpq)(H2O)]·0.25nH2O}n (16), [Mn(Medpq)(PDC)·H2O]n·2nH2O (17), based on 1,10-phenanthroline derivatives (2-methyldipyrido[3,2-f:2',3'-h] quinoxaline, Medpq) and aromatic carboxylic acid (1,2-H2BDC= 1,2-benzenedicarboxylic acid, 1,4-H2BDC= 1,4-benzenedicarboxylic acid, H2PDC= 2,3-pyridinedicarboxylic acid) as the mixed ligands coordinated with transition metal, were synthesized under hydrothermal conditions. Compound (11) exhibits a zero-dimensional structure with 1,2-BDC-Ni-Medpq as building units. Compounds (12)-(17) all exhibit one-dimensional infinite chain structure. The quantum chemical calculation of (11) was performed by using the Gaussian 03 Program. The results show that the valence-bond of Ni(Ⅱ) and the coordinated atoms all belong to the covalent bond category. Comparing with complex (14), the fluorescent properties of complexes (12), (15) were relatively better. The emission bands of complexes (12) and (15) are located at 567.7 nm (yellow light) and 638.7 nm (orange light), respectively. The photocatalytic activity of complexes (12) and (13) was investigated by degradation of dye, respectively. The results show that the catalytic performance of (12) is much better than (13) due to their different central ion.