Structure Chemistry And Spectrum Research Of Transition-metal/3-methylbenzoic Acid Coordination Compounds

In recent years, the potential application of metal-carboxylate coordinationcompounds in functional materials (such as: non-linear optical materials,superconducting materials, magnetic materials, fiber rotation material, zeolite, etc.)have been widely attracted by people, Supramolecular chemistry has become the hotarea of coordination chemistry. In this paper,3-methylbenzoic acid was used as the firstligand and N-heterocyclic compounds were also used as the second ligand,11metal-carboxylate compounds were synthesized by the reaction of ligand anddifferent metal ions in hydrothermal condition, Moreover, the weak interactions andsupemolecular structure baseing on the weak interactions were researched in detail.The main works of this paper are as follows:1.11metal-carboxylate compounds were synthesized by the reaction of ligandand different metal ions in hydrothermal condition.2. The crystal structure of11compounds were determined by using X-ray diffraction.Among them, compound4[Zn(2,2’-bipy)(L)2] is a isolated monuclear cage-likestructure; compound1[Cu(HL)(L)2]2, compound3[Zn(2,2’-bipy)(L)Cl]2, compound5[Cd(2,2’-bipy)(L)2]2H2O and compound9[Zn(phen)(L)2]2are isolated dinuclearcage-like structure; compound10[Cd(phen)(L)2]2[Cd(L)2] and compound11[Mn(phen)(L)2]2[Mn(L)2] were isolated trinuclear cage-like structure; compound2[Gd(L)3] n, compound6[Co(L)2(4,4’-bipy)]n, compound7[Cd(L)2(4,4’-bipy)]nandcompound8[Zn2(L)4(4,4’-bipy)]nare one-dimensional infinite chain structure. theweak force and supermolecular structure of the11crystal compounds were discussedin detail. Among them, two-dimensional network structure of compound1is formedby π-π stacking; Two-dimensional network structure of compounds2and8areformed by C–H···Π from one-dimensional infinite chain; two-dimensional networkstructure of compounds3is formed by the weak interaction of C–H···Cl; The isolatedmonuclear cage-like structure of compounds4was expanded into a one-dimensionalinfinite chain structure by C–H···O; The isolated dinuclear cage-like structure of compound5was expanded into the two-dimensional structure by the intermolecularhydrogen bonds; The two-dimensional structure of compounds6,7,9,10and11are formed by C–H···O weak interaction.3. Most of the compounds were characterized by IR spectra, solid UV diffusereflectance spectra, fluorescence spectra and some compounds were characterized byXRD, TGA and two-dimensional infrared spectroscopy. Fluorescence spectra show:the compound5[Cd(2,2’-bipy)(L)2]2H2O and8[Zn2(L)4(4,4’-bipy)]nare both havestrong emission peak(compound5at388nm (λex=345nm) and compound8at389nm(λex=330nm)). The decay curves are well fitted into a double-exponential function,When excited at345nm for5, the emission peak at388nm is measured,5has verylong life scan, tτ1=3.027ns, τ2=1.017ns respectively. When excited at330nm for8,the emission peak at389nm is measured,8has very long life scan, τ1=10.43ns, τ2=3.137ns respectively. The properties of compounds5and8may make them excellentcandidates for potential photoactive materials.XRD measurement proved that thecompounds3,5,6and8should be a pure phase and the thermal stability of the fourcompounds are measured by thermogravimetric analysis. Moreover, Two-dimensionalinfrared spectroscopy under hot and magnetism perturbation were researched forcompounds2,3,6and8.4. After determining the crystal structure of compound, adopting thepseudo-potential calculation of Hartree-Fock, The program Gaussian03w was used tocalculate and analysis single-point energy、dipole moment and nonhydrogen netcharge of the compound1and compound10.