| Cucurbit[n]uril (Qn) family, as a new type of macrocycle molecular host, has been the subject of much interest in recent years because of its structural specialties and its potential applications as functional materials. The synthesis and the fundamental properties of Qn have been delineated by the pioneering work of the research groups of Mock, Kim, and Day, and have led to their applications in many fields. The aim of this dissertation is to construct new Qn-Based coordination complexes and to synthesis substituted Qn. This dissertation is mainly composed of four parts: Part I: Twelve Q5-based metal complexes were synthesized and structurally characterized. They are [K4(C30H30N20O10)2(HCONH2)2(H2O)2Cl2]Cl2(CH3OH) (H2O)17.5 (1), {[Ba2(C30H30N20O10)Cl](NO3)(H2O)5}Cl2(H2O)2 (2), [Cd(C30H30N20 -O10)Cl2](CH3OH)2CdCl4-(H3O)2+(H2O)4 (3), [Pb2(C30H30N20O10)Cl2]2PbCl6(H2O)14 (4), [Hg(C30H30N20O10)Cl2(H2O)]HgCl4(H2O) 7 (5), {[La(C30H30N20O10)Cl]LaCl -(H2O)9Cl4(HCl)(H2O)7 (6), {[La2(C30H30N20O10)(NO3)](NO3)(H2O)4}(NO3)4(H2O)2 (7), {[La2(C30H30N20O10)Cl](H2O)5(NO3)}(NO3)2Cl2(H2O)6 (8), {[LaK(C30H30N20O10) -Cl]Cl(H2O)3}Cl2(H2O)11 (9), {[NdK(C30H30N20O10)Cl]Cl(H2O)3}Cl2(H2O)14 (10), {[CdK(C30H30N20O10)Cl]Cl(H2O)}CdCl4-(H2O)7(H2O)+ (11) and {[BaK(C30H30N20O10) -(NO3)](H2O)5}(NO3)2(H2O)6.5 (12). Crystal structural analysis reveals that complexes (3) and (5) exhibit opened molecular capsules formed by Q5 and poisonous metal ions (Cd2+ and Hg2+), while (1), (2) and (4) show closed molecular capsules formed by Q5 and metal ions K+, Ba2+, and Pb2+. A chlorine anion was encapsulated in the molecular capsules of (1), (2), (3), (4) and (5). Crystal structural analysis reveals that complexes (6), (7) and (8) exhibit a molecular capsules structure respectively, in which, complex (8) encapsulate a chlorine anion, complex (9) encapsulate a nitrate anion, and complex (10) encapsulate a chlorine anion in the presence of equimolar amounts of chlorine anion and nitrate anions. Crystal structural analysis reveals that complexes (9), (10), (11) and (12) show that the same Q5 can coordinate different metal ions to form hetero-bimetallic molecular capsules.Part II: Nine 1-D tubular structures based on Qn and metal ions, namely, [(C36H36N24O12)(H2O)8Sr2Cl]Cl3(H2O)10 (13), [(C36H36N24O12)(H2O)10Sr2]Cl4(HCl)3 -(H2O)5 (14), [(C36H36N24O12)(H2O)6Sr2Cl2]Cl2(H2O)4 (15), [(C36H36N24O12)(H2O)6 (C4H4O)Sr2Cl2]Cl2(H2O)2 (16), [(C36H36N24O12)(H2O)<sub>10Ca2]Cl4(H2O)31 (17), [(C36H36N24O12)(H2O)10Ca2]Cl4(HCl)(H2O)16 (18), [Cu(H2O)4Q6](NO3)2(H2O)7 -(CH3OH) (19), {[Cu3(H2O)6(Cl)6Q6](H2O)3·(CH3OH)7.5}n (20) and [(C48H48N32O16) -La2K(H2O)18]Cl7(H2O)21 (21), were prepared and structurally characterized. Three coordination polymers (13), (14) and (16) were constructed from Sr2+ and Q6 in different conditions. The polymers (13) and (14) undergo a solid-state, crystal-to-crystal transformation upon heating, giving a same columnar form (15). The tubular structure (17), which constructed from Ca2+ and Q6, converted to another tubular structure (18) in solution. A zigzag like Q6-based coordination polymer (19) and a tubular Q6-based coordination polymer (20) were synthesized, showing clearly how to control the reversible and mutual interconnections between ligand and metal ion under the guide of coordination chemistry. First coordination polymer (21) based on Q8 was synthesized and characterized too.Part III: Although the Qn are potentially useful, their practical applications have been limited mainly due to their poor solubility in common solvents. The addition of K+ to the reaction mixture of Qn leads to the formation of complex of [H2O@Q5K22+@Q10]Cl2(HCl)(H2O)37 (22),of which one water molecular is encapsulated in Q5 and Q5 is encapsulated in Q10. Three partially methyl substituted cucurbituril, Me5Q5 (24), Me6Q6 (25) and Me2Q5 (26), were synthesized from methyl-glycoluril (23) and dimethyl-glycoluril. They were characterized by 1H NMR and single crystal X-ray diffraction. Ab initio calculations showed that each isolated methyl substituted cucurbit[n]uril is the most stable form among its all possbile isomers. Most importantly, Me5Q5 (24) and Me2Q5 (26) have excellent solubility in water.Part IV: A series of photochromic materials based on Qn and polyoxometalates were prepared. These materials were investigated by IR spectrums and UV-vis spectrometry. UV-vis spectra of these photochromic materials reveal their excellent photochromic specialties, of which maybe used in many fields.
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