Synthesis And Properties Studies Of Supramolecular Complexes Constructed By N, N, N’,N’-Tetra (A-naphthylmethyl) Ethylenediamine

Supramolecular second-sphere coordination is a new type of supramolecular self-assembly method in recent years. Second-sphere coordination refers to the interaction between the metal complex and any chemicals. Second-sphere coordination molecule is constituted by two interactional "ball". The first layer mainly refers to the traditional inorganic complexes, and the second layer refers to second-sphere ligand that interacts with metal complexes through non-covalent bond. Using it to build a specific size hole or tunnel to achieve molecular recognition is one of the main applications.N-bidentate ligands [N, N, N’, N’-tetra (a-naphthylmethyl)-ethylenediamine, L] was designed and synthesised in this paper, The structure of L was characterized through 1H NMR, IR, P-XRD and X-ray single crystal diffraction, and its fluorescent properties was tested and analyzed. Solid fluorescence tests show that its maximum excitation wavelength is 278 nm and the maximum emission wavelength is 389nm. The fluorescence absorption peak of L is strong.New types of supramolecular host framework were formed by the second-sphere coordination through protonated L as a secondary ligand and the metal complex anions [MCl4]2- (M=Cu, Mn, Co) which two were bridged by methanol or ethanol via strong hydrogen bonds N-H...O and O-H...Cl, and then new secondary spherical supramolecular compounds (crystal 1,2,3,4) were synthesised, the framework achieved the inclusion of dichloromethane molecules as guest molecules. Also, we found that methanol and dichloromethane play the different roles in these structures. Alcohol, ethanol molecules play the role of a bridge connect the [MCl4]2- and proton ligand molecules, and the dichloromethane fill in the supramolecular framework by the weak van der Waals force. P-XRD shows desorption and adsorption process of the dichloromethane molecular.A new supramolecular host framework [H2L]2+·[Cu2Br4]2-·[H2O] (5) was formed by second-sphere coordination through N-H...Br between protonated L and metal complexes. A dinuclear copper second-sphere supramolecular framework was formed, the framework achieved the inclusion of water molecules as guest molecules. We also try to build the new supramolecular host framework with other metal bromide, and [H2L]2+·[ZnBr4]2-·[CH3OH]·[CH2Cl2] (crystal 6) was formed by second-sphere coordination via N-H...Br between protonated L and [ZnBr4]2-, the structure of crystal 6 is similar to the crystal 1-4.We have explored the effect of the supermolecule structure which was built based on second-sphere coordination on the fluorescence properties of the ligand. Solid fluorescence tests show that the fluorescence intensity of crystal 1,2 and 5 decreased significantly, or even quenching. This achieved the control of the fluorescence property through second-sphere coordination. For example, fluorescence properties of ligand in crystal 1 were recovered after the second ligand structure was destroyed. This made it achieved the reversible transformation of the fluorescence property between the ligand and the second ligand structure that is the "on" and "off’ of the fluorescence property.