The D Orbital Reconstruction Of Copper Porphyrins And Transformation Of Catalytic Properties Of Their Complexes

The allosteric effect of metalloproteins is closely related to their function.It is one of the important topics in the research of metalloproteinases to construct metal complexes with special structures and induce the unique functions of complexes with the help of allosteric effect of ligands.In this paper,the relationship of metal d orbital structures to the length of double-bow skeleton,macrocyclic distortion,coordination geometry of porphyrin ligands,and that of the electro-/ photo-catalytic properties to the allosteric effect of metal d orbitals are found,which provides valuable experimental and theoretical supports for the study of the allosteric effects of metalloproteins and for the optimization of catalytic properties of metal complexes.The work of this paper is as follows:1)By using the double-bow strategy,four copper()porphyrins(1-Cu,2-Cu,3-Cu and4-Cu)with consecutive changes in distortion were obtained by one-pot method.The configuration of the ligands was regulated by the ortho-cis double-bow framework located on the same side of the porphyrin plane.The X-ray,FT-IR,UV-vis and EPR techniques were used to characterize these copper complexes,revealing the relationship between the electronic structure of the central metal and the change of ligand geometry.The continuous shortening of the double bow skeleton in length leads to the increase of the macrocycles in the distortion degree,the deviation of each atom on the macrocycle from the mean plane of the ring increases,and the discontinuous red shift of the spectra appears,indicating that the double bow strategy realizes the regulation of the macro size of porphyrin units.2)The electrochemical transformationes and the generation of various free radical species of four copper porphyrins were tracked by spectro-electrochemical technique.The visible light catalytic performance of four complexes was investigated by using Methyl Orange(MO)as degradation objects.The photocatalytic performance of 1-Cu is better than that of the other three complexes with the increase of their distortion degree by comparing the photocatalytic results of the double-bow copper porphyrins.It is verified that the electronic structure and ground state energy of the double bow copper porphyrins are changed due to the highly twisted deformation of the macrocycle,and the catalytic capacity of the double bow copper porphyrins is optimized.3)The molecular orbital energy,single point energy and the energy changes in the hydrogen evolution reaction(HER)process of 1-Cu,2-Cu,3-Cu and 4-Cu were studied and analyzed by Density Functional Theory(DFT)method,and the conformation effect of the series of the copper porphyrins was quantified.The electron behavior and energy changes of 1-Cu are obviously different from those of the other three complexes.It is further confirmed that the highly deformed porphyrin causes the reconstruction of d-orbital of copper(),which makes the complexes have stronger electron transfer ability and higher catalytic potential.The changes of structure and properties of copper porphyrins with different twist degrees were discussed,which provided theoretical guidance for the design of functional metalloporphyrins complexes.