Study Of Optical Limiting Properties And Mechanism Of Some Prophyrin Polyoxometallate Hybrids

The purpose of this thesis is to study the nonlinear optical properties and optical limiting properties of porphyrin-polyoxometalate hybrids through Z-scan testing techniques.The effects of different polyoxometalates on the third-order nonlinear optical properties and optical limiting performance of the material were explained by means of transient absorption spectroscopy measurements from the nonlinear absorption mechanism.The specific research content is as follows:1.The porphyrin derivative TPP-Tris and the Dawson polyoxometalate[N(C4H9)415[P2W15V3O62H4]were combined to form an organic-inorganic hybrid material through a covalent bond,elemental analysis,NMR and other common methods were used for characterization.The nonlinear absorption curve of the material was measured by Z-scanning technique.The results show that the TPP-Tris and TPP-POM samples undergo RSA/SA conversion at high incident energy.Although the hybrids improve the optical limiting properties of the material,the nonlinear limiting performance of the two at high incident incident light intensities is reduced due to the non-linear absorption RSA/SA conversion.Using the flash photolysis technique to obtain the transient absorption spectra of the sample shows that the reason for the non-linear absorption RSA/SA conversion is due to the two-photon absorption of the triplet state of the 5,10-A2B2 type porphyrin derivative material.Therefore,in the preparation of porphyrin derivative optical limiting materials,the type of 5,10-A2B2,which may have a non-linear absorption property transition,is synthesized as far as possible.2.Tetraphenylporphyrins were combined with three Dawson polyoxometalates to form organic-inorganic hybrid materials TPP-Fe,TPP-Mn,and TPP-Zn through ionic bonds.The optical limiting performance curve of the material was measured by a Z-scanning device.According to the calculation method of the reference,the NAF value of the nonlinear attenuation factor of the hybrid was much larger than that of tetraphenylporphyrin,among which the TPP-Zn NAF value.The biggest reason is that the ratio of the excited state absorption cross-sectional area of the hybrid material to the ground-state absorption cross-sectional area?exT/?0 is greater than the ?exT/?0 of the tetraphenylporphyrin,and the value of the ?6exT/?0 of the TPP-Zn is the largest.Shows that the porphyrin polyoxometalate hybrid material improves the optical limiting properties of the material.According to the transient absorption spectra obtained by the flash photolysis technology and the calculated triplet minus the ground state,the absorption extinction coefficient ??T is further explained by the optical limiting performance difference between the four samples.The larger the ??T value,the better the optical limiting performance...