Supra-molecular Structure Study On Transitional Metallic Compounds Based On Hydrogen Bonding And Aromatic Stacking

The properties and functions of chemical materials depend on the array of molecular components, as well as the component itself. The field of supra-molecular chemistry focus on non-covalent interactions, such as hydrogen bonding,π-πstacking, van der Waals and hydro-phoblic interaction, etc., employed to fold micromolecules into well-defined macromolecules and even supra-molecules. The cooperation between non-covalent interactions amplifies weak interaction, and forms strong interactions with directionality and strength.Study on the structure and forming process of supra-molecules, reveals the nature of intermolecular forces, and rules molecules obey in the forming process. It's important to the structure prediction and synthesis of new organized, functional materials, such as catalyst, electrode, adsorbent and optical materials, etc..In this paper, 7 unreported transitional metallic compounds, (Ⅰ)～(Ⅶ), are synthesized in our lab, with 1,10-phenanthlorine (phen), imidazole (imid)and benzi- midazole (bzim) as neutral ligands, and 2-hydroxybenzoato (2-HBA), 4-hydroxybenzoate (4-HBA), 2,4-dihydroxy-benzoate (DHBA), thiodiacetato (TDA) and terephthalato (Tp) as anionic ligands; their three-dimensional structure were determined by single X-ray diffraction method.This paper debates on the relationship of ligands and non-covalent interactions such as hydrogen bonding andπ-πaromatic stacking, and the influence of ligands and non-covalent interactions to the zero-dimensional to three-dimensional topological structure of supra-molecular metallic compounds.π-πaromatic stacking relates to efficient packing areas of aromatic rings; Multi-cyclic compounds tend to formπ-πstacking than monocyclic compounds. Polarity of aromatic molecules is also crucial toπ-πaromatic stacking; Double-substituted DHBA ligands are prone to formπ-πstacking than mono-substituted HBA ligands. Double-substitution of hydroxyl groups on benzene rings amplifies the polarity of benzene rings.π-πaromatic stacking influences compound structure; In the (Ⅲ) compound, intra-molecularπ-πstacking occurs between phen and O5-HBA ligands binding Cd~Ⅱions, ??leading phen and O5-HBA ligands nearly parallel. C-H...πinteractions also influence compound structure and packing mode: In the (Ⅶ) compound, C-H...πinteraction occurs between C25-H25 bond and N33-imid ligand, leading Ni~Ⅱatom and N33-imid ligand nonplanar.Hydrogen bonding andπ-πstacking play a crucial role in 3D architecture forming of supra-molecular compounds; 0D and 1D compound are linked by hydrogen bonding andπ-πstacking to form various 1D, 2D and 3D topological structure. Hydrogen bonding andπ-πstacking cooperate to form 3D net-like supra-molecular systems. Low-dimension structure crosslink to high-dimension supra-molecular systems; In the (Ⅵ) compounds, lattice water Tape crosslink adjacent Zigzag supra-molecular chains. Supra-molecular topological structure relate to compound conformation; In (Ⅴ) compound, 1D Helix supra-molecular chain due to the folding conformation of TDA; In (Ⅳ) compound, T-shaped (Brick) 2D structure forms due to the 1D Zigzag polymeric chains.Through the structure study on supra-molecular transitional metallic compounds, it's further understood about how the ligands and non-covalent interactions, such asπ-πstacking and hydrogen bonding, influence the topological structure of supra-molecular compounds.