Self-Assembly Synthesis And Characterization Of Chiral Complexes Based On Polydentate Benzimidazoles Ligands

Chiral compounds play an important role in the field of biomedicine.However,in the process of chemical synthesis,in addition to efficient chiral catalytic synthesis,chiral compounds synthesized with non chiral compounds as raw materials usually contain 1:1 enantiomer racemates.Direct application of racemate of chiral compounds as drugs and pesticides will cause great harm to human health.Therefore,the purification of racemate as a single chiral compound has great significance for people’s health and living environment.This paper synthesized two different non chiral ligand raw materials,and synthesized different chiral supramolecular metal organic framework materials by adjusting reaction temperature,volatilization rate,reactant ratio,etc.The chiral spontaneous phenomenon was verified through circular dichroism（CD）testing,and complex 5 was attempted to be resolved,providing a feasible approach for the future synthesis and resolution of chiral complexes through non chiral raw materials.The main content of this paper is divided into the following four parts:1.Synthesis and Characterization of Mononuclear Chiral Complex[M(C₃₄H₃₂N₁₀)（BF₄^-）₂（CH₃OH）x]（M=Co,Cu）Mononuclear chiral complexes 1a[Co(C₃₄H₃₂N₁₀)（BF₄^-）₂（CH₃OH）₂]and 2a[Cu(C₃₄H₃₂N₁₀)（BF₄^-）₂（CH₃OH）₃]were synthesized by solvent evaporation.The lattice parameters of complex 1a are a=11.37?,b=14.88?,and c=23.11?,α=β=γ=90°,Z=4,Z’=1,V=3914?³,the lattice parameters of complex 2a are a=14.65?,b=17.00?,and c=17.46?,α=β=γ=90°,Z=4,Z’=1,cell volume V=4353?³.The chiral enantiomer 1b and 2b of complexes 1a and 2a were found by X-ray single crystal diffraction analysis.The CD signals of complexes 1a and 2a were measured respectively.The results showed that complexes 1a and 2a were unevenly chiral and spontaneously resolved.2.Synthesis and Characterization of Binuclear Chiral Complex[Cu₂(C₃₄H₃₂N₁₀)（BF₄-）₄（CH₃OH）₂]The binuclear chiral complex 5a[Cu₂(C₅₀H₄₀N₁₀)₂（BF₄^-）₄（CH₃OH）₂]was synthesized by solvent evaporation.The complex was crystallized in the hexagonal crystal system chiral space group P65.The lattice parameters of complex 5a are a=21.93?,b=21.93?,and c=45.80?,α=β=90°,γ=120°,Z=6,Z’=1,cell volume V=19092?³.The chiral enantiomer 5b of complex 5a was found by X-ray single crystal diffraction analysis,and the complex 5b was also crystallized in the hexagonal crystal system,and the space group was P61.The final results of ligand infrared,liquid UV,and CD tests on complex 5a showed that the complex 5a also exhibited asymmetric chiral spontaneous resolution.3.Synthesis and Characterization of Hexanuclear Center Complex[Co₆(C₃₆H₈N₃)₆Cl₆（DMF）_5.5（H₂O）_3.5]In order to investigate whether chiral complexes can be formed under alkaline conditions,a small amount of sodium formate was added to adjust the solution to weak alkaline conditions.A six core metal organic macrocyclic complex 8[Co₆(C₃₆H₈N₃)₆Cl₆（DMF）_5.5（H₂O）_3.5]was finally obtained using solvothermal method.The complex is crystallized in the central space group P of triclinic system,and the cell parameters are a=14.62?,b=17.54?,c=18.02?,α=99.41°,β=96.94°,γ=94.64°,Z=2,Z’=1,cell volume V=4504?³.Compared with common naphthalene imidazole complexes,the N-H on some imidazole rings in this complex removes H⁺,resulting in six more exposed N coordination sites in the ligand.At the same time,free Cl^-in the solvent participates in coordination,forming a six core cobalt cluster.The variable temperature magnetic susceptibility of complex 8 in the temperature range of 2～300 K and the hysteresis loop in the range of-80 k Oe～80 k Oe at 2 K were investigated.The results show that complex 8 has weak spin orbit antiferromagnetic coupling and weak magnetic anisotropy between cobalt.