| In recent years, based on coordinative interactions and diversified supramolecular interactions (such as hydrogen bonding andÏ€-Ï€stacking, etc.), crystal engineering of metal complexes has been the most intensive research topic in coordination chemistry and supramolecular chemistry. With the aims to construct new metal-organic supramolecular frameworks, several aromatic carboxylate derivatives with isoxazole, imidazole or naphthalene rings are choosed as major building ligands their assemblies with 3d or 4f metal ions leading to a series of complexes with novel structures. Based on single-crystal X-ray diffraction analyses, their coordination chemistry, hydrogen bonding andÏ€-Ï€stacking interactions and their roles played in engineering crystals have been studied. TGA, polymorphism, solution conductivity, magnetic or fluorescent properties of some relative complexes have been characterized and discussed.This thesis covers following six chapters:1) The Chapterâ… Preface. The concepts and principles of coordination chemistry, supramolecular chemistry, metal-organic frameworks (MOFs), and crystal engineering were simply introduced. Reviews on the background and significances of MOFs, hydrogen bonding interactions and water clusters or chains that are related with this thesis were also briefly made.2) The Chapterâ…¡. By changing the metal ions, solvents, temperature, co-ligands and synthesis method, a fruitful series of complexes (from 2-1 to 2-13) with structural diversity have been prepared with 3,5-dimethylisoxazole-4-carboxylate (HDMIC) as major ligand. Among the results, some of them are full of challenges: 1) it is the first example that can map out the change of hydrogen bonds in the same ligand system, namely, from O-H...N (strong), through C-H...A (A = N, O) and/or C-H...O/N (weak) to C-H...Ï€(very weak); 2) the weak bifurcated hydrogen bond C-H...O/N with hetero-acceptors in complex 2-3 is firstly observed; 3) a necklace-like water chain has been observed in complex Co(DMIC)2(H2O)4·4H2O (2-10) which is consisted of uniform planar tetra-meric water rings and stabilized by hydrogen bonds with Co(DMIC)2(H2O)4 motifs. The results imply that DMIC is a versatile ligand and the isoxazole ring is a ready acceptor for C-H...Ï€interaction.3) The Chapterâ…¢. With 4-imidazoleacrylic acid (H2IA), Co(HIA)2(H2O)2·2H2O (3-1) , and RE4(H2IA)18 (ClO4) 12 (H2O)9 [RE = Pr(3-2) , Gd(3-3) ] with tri-fold trefoil-like shape have been prepared. In complexes Pr(3-2) and Gd(3-3) , one dimensional nano-channels were formed which incorporated the countered ions acting with the ligands by hydrogen bonds. By increasing the pH value, hexa-fold helix La2(HIA)6(H2O)4·6H2O (3-4) with nanoscale diameter has been assembled, resulting in an interesting three dimensional supramolecular framework in which one dimensional micro-channels being observed. The results demonstrate that the multiple coordination modes and the various existing states of the ligand play major roles in the structural diversity.4) The Chapterâ…£. With 4,5-imidazoledicarboxylic acid and 4,5-dicyanoimidazole as ligands, trans-[Ni(H2IDC)2(H2O)2] (4-1) and Mn(DCI)2(H2O)2 (4-2) have been synthesized. Eight-connected supramolecular topology has been observed in 4-1 based on the mononuclear tectons. With 4,5-dicyanoimidazole as bidentate linker, a ladder-like polymer chain has been formed and its magnetism has been studied.5) The Chapterâ…¤. With 4,4'-Methylenebis(3-hydroxy-2-naphthoic acid) (Customarily named Pamoic Acid, H4PA), we have synthesized a rich family of complexes: (H4N)2Cd(H2PA)2(DMF)2·6H2O(5-1) , [Coâ…¡6(μ3-OH)6(μ3-HCOO)6] (5-2) , M(1,10-phen)2(H2O)2(H2PA)·4H2O [M = Ni(5-3),Zn(5-4),Co(5-5) ],Mn(1,10-phen)2(H2O)2(H2PA)·2H2O (5-6)å’ŒNi(2,2'-bpy)2(H2O)2(H2PA)·4H2O (5-7) . The formation of 5-1 demonstrates that complexes with open nano-cages can be assembled by angular ligands, and its fluorescent property has been studied. Luckily, we have observed a hexa-nuclear prism-like cobalt cluster motif in complex 5-2 acting as six-connected node in the three dimensional framework, and studied its magnetism. Furthermore, we have studied on the shape effects of the building blocks on the crystal engineering of complexes in the serial ionic compounds (5-3 to 5-7) . Differently, we have obtained hydrogen-boned framework in (H4PA)·2DMF (5-8) which also reflects the effects of the shape of building units on crystal engineering.6) The Chapterâ…¥. The polymorphism and reactivity of [Ni(pyridine)4(NCS)2] have been explored, in which new dimorphs depending on solvents (CH3CN, Formâ… or CH3CN/CH3OH, Formâ…¡) and one unusual conductive macro-ionic complex (6-3) [(N-methylpyridinium)n]22n+·[Ni(μ1,3 -SCN)2(NCS)2] n2n- with inspiring conductivity value (205ΔM) have been obtained. The results provide a new insight into polymorphism and reactivity of [Ni(pyridine)4(NCS)2] .Class:O61...
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