| The functionalization of coordination compounds is a fast-developing trend in the fields of chemistry and materials, and the structure-property correlation lies at the foundation of understanding and tuning the properties of molecule-based materials. As known, iron(II) is a classic d6 metal suited for octahedral ligand field, which experiences the synergy between ligand field splitting energy and electron pairing energy to determine its spin states, and further to affect the magnetic property of iron(II)-based compounds. To build novel coordination compounds,discover new magnetic phenomena,and investigate the correlationship between structure and magnetic properties,fourteen transition metal coordination compounds based on azaeyclie ligands have been prepared and strueturally characterized,and the magnetic properties of some of them have been characterized. The thesis is divided into four chapters.In Chapter One, spin crossover is concisely presented along with the research significance and the research background and recent progresses on [FeIIN6] complexes and 5-substituted 1H-tetrazoles ligands were concisely introduced, with emphasis on the ligand field theory and the ligand field splitting energy versus electron pairing energy to determine the spin states. In addition, the purpose and significance of this work were outlined.In Chapter Two, the reactions of achiral ligand 5,5'-(1,4-phenylene)bis(1H-tetrazole) with Zn(NO3)2 in H2O concomitant formation of chiral [Zn(bpt)]n (1) (3D)and [Zn(bpt)]n (2) (3D)and [Zn(bpt)]n (3) (3D) racemic(3D) supramolecular isomers. Interestingly, It is to note that the final product is not always the same, both or just one of the two. That is one may disappear. This result is attracted and expected to afford important information for modern crystal engineering, When Cd(II) and Co(II) was used instead of Zn(II), unfortunately, didn't get expectation results, but get another group complexes [Cd2(H0.67bdt)3]·4H2O (4) and [Co2(H0.67bdt)3]·4H2O (5). In Chapter Three, namely, 5,5'-(1,4-phenylene)bis(1H-tetrazole) was introduced to react with iron(II) salts under hydro(solvo)thermal conditions, yielding six polymeric iron(II)complexes 6-11.Compounds 6-9 were three-dimensional network filled with water solvent molecules. Though the classic [FeIIN6] sphere were observed in 6-9, the high-spin state for iron(II) in [Fe2(H0.67bdt)3]·4H2O (6), the spin crossover state for iron(II) in [Fe2(H0.67bdt)3]·13H2O (7),the low-spin state for iron(II) in [Fe2(H0.67bdt)3]·5H2O (8) and [Fe2(H0.67bdt)3]·15H2O (9), were unambiguously confirmed by both structural and magnetic evidences. Compounds [Fe4K2(SO4)2 (μ3-OH)2(bdt)2·7H2O]·2H2O (10) and [Fe2Na2(C2O4)2(bdt)(μ2-H2O)2] (11) were transition metal and main group metal mixed three-dimensional network.Compounds 10 and 11 had yet to be magnetically characterized due to difficulties concerning product purity and yield.In chapter Four, 5-(4-pyridyl)tetrazole were selected to construct one valence copper three frameworks in hydro(solvo)thermal reaction.Compound [Cu3(4-pt)(CN)2]n (11),Compound [Cu2(4-pt)(SCN)]n (12) and Compound [Cu12(OH)I7(4-pt)4]n (13).Further studies of the influence of halogen and pseudohalogen on structures of copper(I)-tetrazolate. Additionally, photoluminescent property analysis have been carried out and examined.So far, 4 - pt adoptsμ5 bridge league mode have yet to report in Compounds 12 and 14... |
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