Research On Photoinduced Electron Transfer Mechanism Of Cryptochrome Model Molecule F10T

It is found that some organisms in nature can sense magnetic field,which is likely to transform magnetic signal into chemical signal and then be perceived by organisms.At present,most scholars believe that the mechanism of biomagnetic induction free radical pair is the most likely and perfect mechanism of biomagnetic response,and cryptochrome protein is the receptor protein of biomagnetic induction.People are very interested in the photoinduced electron transfer of cryptochrome protein.Because natural cryptochrome protein is not easy to be directly used as the research object,researchers have developed various cryptochrome model systems to replace natural cryptochrome for research.The cryptochrome model compound flavin tryptophan dimer F10 T designed and synthesized by our research group has been proved to be an excellent cryptochrome model system in experiments,but the understanding of F10 T ’s photoinduced electron transfer and photochemical cycle process is still in the hypothesis stage.Based on Gaussian 09 software platform,using the method of calculation and simulation,starting with calculating the excitation properties of F10 T,this paper theoretically explains the photoinduced electron transfer pathway and photochemical cycle of F10 T.In Chapter 2,the theoretical basis briefly describes the Marcus theory of the basic theory of electron transfer,the quantum chemical calculation method of photoinduced electron transfer and the calculation method of the electron coupling matrix element of kinetic parameters,which provides theoretical support for the calculation and research of F10 T.In Chapter 3,the theoretical research part of F10 T excited state properties uses the B3 LYP / 6-311G(d,p)basis set in density functional theory / time-dependent density functional theory to calculate and simulate the ground state,excited state and spectral properties of F10 T,and obtains the structure,energy,orbital and dipole moment of F10 T ground state and excited state,as well as the spectral data under different solvent conditions,It fills the gap of the shortage of basic data in the process of F10 T research,and it is found that under the condition of the same proton solvent or the same aprotic solvent,the greater the polarity,the longer the absorption wavelength.In Chapter 4,the theoretical research part of F10 T photoinduced electron transfer mechanism adopts the B3 LYP / 6-311G(d,p)basis set of time-dependent density functional theory to calculate the electron transfer coupling matrix element of F10 T excitation process,calculate the excited state properties and spectral data of each component of F10 T,and calculate the triple excited state of F10 T.The data of the electron coupling matrix element,the coupling of each component of F10 T and the triple excited state information of F10 T are obtained.It is theoretically speculated that the electron transfer pathway in F10 T is a "super exchange mechanism" independent of the bridge body,and it is given that the initial state of F10 T photochemical cycle process is the triple state.