Synthesis And Molecular Recognition Of Metalloporphyrins And Porphyrin-Salen Dimers

Porphyrin chemistry has already been important in many intersectional investigations such as chemistry, physics, life material and informatics. Metalloporphyrins are of great significance in the field of bioinorganic chemistry, coordination chemistry and host-guest chemistry. Studies on metalloporphyrins have always been a main point. As an important role in biochemistry, metalloporphyrins have been used in biomimic studies of consequence. Molecular recognition of metalloporphyrins and porphyrin-salen dimers have been studied in this thesis, and theoretic chemistry has been performed to investigate. The main content is shown as follows:1. Six new free and zinc porphyrins modified by amino acid derivatives were synthesized and characterized by UV-vis, 1HNMR, IR, CD spectrum; Twelve new free and zinc porphyrin-salen dimers linked by different lenth alkyl chain were synthesized and characterized.2. The molecular recognition of imidazoles by modified zinc porphyrins was studied. The association constants of the system were measured by of UV-vis titration, and affect factors of association constants were discussed, which include the steric configuration of host, guest molecules and temperature; The thermodynamic properties and enthalpy-entropy compensation were considered; The CD spectrum was first time used to study the recognition of this system, according to the results of thermodynamic; The minimal energy conformations and binding mode of host-guest systems were obtained by simulated annealing and quantum chemistry.3. The chiral recognition of amino acid esters by modified zinc porphyrins was investigated. The association constants between hosts and guests were measured. The thermodynamic parameters and enthalpy-entropy compensation relationship were investigated; The enantioselectivities were calculated, among which ZnT(o-BocAla)APP to LeuOMe is as high as 6.9, which is the highest value reported in our system; The relationship between selectivity and temperature has been discussed, which showed that the selectivity will increase when the experimental temperature decreases, and it is expected to be useful to the application of chiral recognition; 1H NMR was investigated and the binding mode of this chiral recognition was revealed; CD spectrum of host-guest complexes was also investigated; Simulated annealing and quantum chemistry were in company with investigating the binding mode of this system theoretically.4. The recognition of DABCO by Zinc porphyrin-salen dimer ZnPSC10 was studied.1H NMR titration was used to study the association process of the system, considering that the ternary sandwich conformations are the stable conformations of this system; The respectively mensuration of thermodynamic parameters of the dimers formed by two different parts was presented first time; Molecular mechanics and quantum chemistry were in company with investigating the stable ternary sandwich conformations of this system theoretically.5. The recognition of three guest molecules pyridine, DABCO and pyrazine by Zinc porphyrin-salen dimer ZnPSC10 was studied. The association ability of three guests was in order pyridine>DABCO>pyrazine; The higher HOMO energy was, the stronger association ability of the guests were; Molecular mechanics and quantum chemistry were used to estimated the most stable conformations of this system.