| Summary: | 碩士 === 國立中正大學 === 化學暨生物化學研究所 === 104 === This thesis consists of three chapters. In chapters one and two, we investigated the excited state proton transfer of 1-hydroxy-8 -sulfanyl-2- naphthaldehyde (HSNA) and 1,8-dihydroxy-2,7- naphthdialdehyde (DHNDA). In chapter three, we studied the performance of the multi-coefficient density functional theory (MC-DFT) using the recently developed “calendar” series of basis sets.
In chapter one, we studied the proton transfer reactions of 1-hydroxy-8 -sulfanyl-2- naphthaldehyde (HSNA) on both ground state (S0) and the lowest singlet excited state (S1). On the ground state (S0), we found two stable structures HSNA (N1) and N2. The N2 was lower in energies than N1 by 0.54 kcal/mol. We predicted that the absorption wavelengths of N1 and N2 were 410 and 421 nm respectively. On the first excited state (S1) surface, we found two stable structures N2* and N1*. The N2* was higher in energies than N1* by 2.29 kcal/mol. We predicted that the emission wavelengths of N1* and N2* were 473 nm and 447 nm. Our calculation showed that N1* can undergo a concerted double proton transfer reaction to become a tautomer T2-1* and its emission wavelength was predicted to be 704 nm. A comprehensive 2-D PES plot also confirmed the deduction.
In chapter two, we studied the proton transfer reactions of 1,8-dihydroxy-2,7-naphthdialdehyde (DHNDA) on both ground state (S0) and the 1st singlet excited state (S1). On ground state (S0), we found two stable structures NB and NA. The NA was higher in energies than NB by 0.90 kcal/mol. The predicted absorption wavelengths were 396 nm for NA and 383 nm for NB. The experimentally observed absorption wavelengths (~380 nm) were almost the same as the predicted values. Our calculation also showed that the NA* is not a energy minimum on S1 surface. However the TA1* which is obtained from NA* by a single proton transfer reaction was stable on the S1 surface. A second single proton transfer reaction can then follow to generate the TA2* molecule. The predicted emission wavelengths for TA1* was 491 nm and for TA2* was 611 nm. The predicted emission wavelength of TA2* is consistent with the experimentally measured value (~650 nm).
In chapter 3, we tested the performance of our multi-coefficient density functional theory (MC-DFT) on thermochemical kinetics data of 211 accurate energies using the “calendar” series of basis sets (jul-cc-pVTZ、jun-cc-pVTZ、may-cc-pVTZ). Our methods also include energy corrections at SCS-MP2 and MP4 levels. The best Performance/Cost ratios was obtained at the DSD-BLYP/ may-cc-pV(T+d)Z level including MC-SCS-MP2 correction with an MUE of 0.86 kcal/mol .
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