Study On Syntheses,Crystal Structures And Properties Of Salamo-Like Transition Metal (Ⅱ) Complexes And Dual Channel Chemical Sensors

Salamo-like compounds have attracted much attentions in the field of coordination chemistry.These compounds have better flexibility and stability than salen-like compounds.Because of the introduction of more electronegative O atom,hydrolysis and exchange reactions are more difficult to occur,make the salamo-like compounds as ligands react with metal ions to form a variety of crystal coordination modes,novel structures,and have more supramolecular structures.In this thesis,half-,single-and bis-salamo-like ligands HL¹,H₅L²and H₂L³ have been designed and synthesized,and the crystals of their complexes have been obtained.The structures of the complexes were determined by X-ray crystallography.The structures were characterized by Hirshfeld surfaces analyses,element analyses,DFT theoretical calculations,infrared spectra and ultraviolet-visible spectra.The results show that the complexes have good luminescent properties and antibacterial activities.Complex 1:C₄₀H₄₆Br₄Co₃N₄O₁₆,Mr=1334.76,triclini,space group P-1;Complex 2:C₃₀H₄₈Br₂Ni₃ N₄O₁₈,Mr=1088.61,orthorhombic,space group Pbcn;Complex 3:C₃₅H₃₂CaZn₂N₄O₁₄,Mr=903.49,triclini,space group R32;Complex 4:C₃₅H₃₂SrZn₂N₄O₁₄,Mr=951.04,triclini,space group R32.In addition,the application of salamo-like compounds in the field of chemical sensors was also studied.H₅L² and H₂L³ can recognize Cu²⁺ion in a wide pH range with double channels and high selectivity,realizing the naked eye recognition without any analytical instrument under visible light.The sensor H₅L² can be used not only to detect Cu²⁺in various water samples,but also to detect Cu²⁺in water samples quantitatively by RGB analysis.In addition,the L²-Cu²⁺complex formed by the interaction of H₅L² and Cu²⁺can used as a new chemical sensor to realize continuous recognition of amino acids.The recognition mechanism of the sensor L²-Cu²⁺is explained by calculating the orbital energy difference and analyzing the high-resolution mass spectrum and nuclear magnetic hydrogen spectrum.The fitting of job curve,the calculation of the constant and the lowest detection line,and the results of fluorescence titration and ultraviolet titration show that the two chemical sensors have high selectivity,high sensitivity and strong stability in a certain period of time.