Study On The Effect Of Weak Interactions And Symmetry In Crystal Architecture

Aromatic polycarboxylic acids can form coordination polymers with novel structures and properties. The substituents on modified aromatic carboxylic acids, as well as the metal ions, are the essential factors for controlling the topology of coordination polymers. In this research, based on the idea of crystal engineering, 7 coordination polymers have been designed and synthesized through the combination of the first row of the transition metal ions Cu(â…¡), Zn(â…¡) and Mn(â…¡) and aromatic carboxylates or their derivants by means of diffusion, solution, hydrothermal and solvothermal reactions. The structures and properties of these complexes have also been characterized. The influences of weak interactions such as hydrogen bonding,π…πinteractions and the symmetry of the tectons on the assembly of coordination polymers have also been investigated. The complexes are:(1) Complex 1 (C₁₈H₃₀Cu₃N₆O₁₅)_n (2) Complex 2 (C₁₂H₁₈CuN₂O₄)_n (3) Complex 3 (C₂₀H₃₆O₈Zn)_n (4) Complex 4 (C₁₄H₂₇NO₉S₃Zn)_n (5) Complex 5 (C₃₀H₂₆N₂O₁₀Zn₂)n (6) Complex 6 (C₁₅H₁₃NO₅Zn)_n (7) Complex 7 (C₄₈H₄₆Mn₃N₄O_16n1. Two coordination polymers (Complex 1 and 2) of Cu(â…¡) ion and 1,3,5-benzenetricarboxylic acid or 2,3,5,6-tetramethlyterephthalic acid have been synthesized and characterized. The reaction velocities of the assembly were controlled by the diffusion of the ammonia. The C₃ symmetry of 1,3,5-benzentricarboxylic acid causes complex 1 to have 2D structure and the C₂ symmetry of 2,3,5,6-tetramethlyterephthalic acid caused complex 2 to have 1D structure. Hydrogen bonding,π…πinteractions and the symmetry of the tectons are essential factors in the structures and properties of the two complexes.2. Two coordination polymers (Complex 3 and 4) of Zn(â…¡) ion and 2,3,5,6-tetramethlyterephthalic acid or 2-aminoterephthalicacid have been synthesized and characterized. The methyl substituents result in the formation of hydrophobic 1D structure of Complex 3 and the amino substituents results in the formation of hydrophilic 2D structure of Complex 4.3. Three coordination polymers (Complex 5, 6 and 7) of Zn(â…¡), Mn(â…¡) and 1,4-naphthalenedicarboxylic acid or 2,6-naphthalenedicarboxylic acid have been synthesized and characterized. The influences of the metal ions and the ligands on the structures of the coordination polymers have also been discussed.