本實驗利用了鄰硝基苯胺以及對羥基苯乙酮為反應物合成2-（2′-羥基-5′-乙醯苯基）-苯並三唑(1)、2-（2'-羥基-3'-（2-呋喃基）-5'-乙醯苯基）-苯並三唑(2)、2-（2'-羥基-3'-苯甲醯基-5'-乙醯苯基）-苯並三唑(3)，利用了鄰硝基苯胺與對羥基苯甲醛為反應物合成2-（2′-羥基-5′-甲醯基苯基）-苯並三唑(4)、2-（2'-羥基-3'-（2-呋喃基）-5'-甲醯基苯基）-苯並三唑(5)、2-（2'-羥基-3'-苯甲醯基-5'-甲醯基苯基）-苯並三唑(6)。將產物溶於氯仿中，以溶液狀態測定各化合物的紫外線吸收光譜，探討其對紫外線的吸收效果。利用密度泛函理論計算方法驗證並對實驗結果解釋。根據紫外線吸收光譜的結果，可推測若在5′位置接上具拉電子基效應的官能基，可增加分子內氫鍵強度，且分子若擁有碳氧雙鍵，將增強分子的共軛系統，並有效在短波長(250nm-300nm)處提升吸收紫外線的能力。同時討論化合物(4)於不同溶劑中紫外線吸收光譜的變化。利用前緣分子軌域理論分析化合物(1)至化合物(6)，發現分子內質子轉傾向於激發態下進行，同時以理論計算探討紫外線吸收峰來自哪一能階的電子躍遷。

In this experiment, o-nitroaniline and p-hydroxyacetophenone were used as starting materials to synthesize 2-(2’-hydroxy-5’-acetylphenyl)-benzotriazole (1), 2-(2'-hydroxy-3'-(2-furoyl)-5'-acetylphenyl)-benzotriazole (2), and 2-(2'-hydroxy-3'-benzoyl-5'-acetylphenyl)-benzotriazole (3). And o-nitroaniline and p-hydroxybenzaldehyde were also used as starting materials to synthesize 2-(2’-hydroxy-5’-formylphenyl)-benzotriazole (4), 2-(2'-hydroxy-3'-(2-furoyl)-5'- formylphenyl)-benzotriazole (5), and 2-(2'-hydroxy-3'-benzoyl-5'- formylphenyl)-benzotriazole (6). The respective UV spectrum of those compound was obtained by dissolving in chloroform, and compound 4 was examined the solvent effect of UV absorption. The six UV spectra showed no much difference in absorbed spectral width, however compound 4 showed better absorbance at 266.0 nm compared to others, which may be due to the C5’ aldehyde group causing a better resonance from 2C’ hydroxyl group as to resulting a better h-bonding between the two rings. The solvent effect on the compound 4 showed the absorption at 240.2 nm in dichloromethane disappeared concomitant with the red shift of 266.0 nm in dichloromethane to 271.0 nm in ethyl acetate. The calculation method of density functional theory was used to verify the interpretation of the experimental results. According to the results of the ultraviolet absorption spectrum, it can be speculated that if a functional group with an electron-withdrawing effect attached to the C5’ position, the strength of intramolecular hydrogen bonding can be increased, which will enhance the conjugation system of the molecule and effectively improve the ability to absorb ultraviolet rays at short wavelengths (250nm-300nm). Frontier molecular orbital theory was used to analyze compounds (1) to (6), and it was found that intramolecular protons tended to proceed in an excited state. Theoretical calculations were used to explore the energy transition of the ultraviolet absorption peak as shown and discussed in the results section of this thesis.

1. Molina, M. J.; Rowland, F. S., Stratospheric sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone. Nature 1974, 249 (5460), 810-812.
2. Fahey, D., Twenty questions and answers about the ozone layer: 2006 Update 2006. NASA: 2006.
3. Rigby, M.; Park, S.; Saito, T.; Western, L.; Redington, A.; Fang, X.; Henne, S.; Manning, A.; Prinn, R.; Dutton, G., Increase in CFC-11 emissions from eastern China based on atmospheric observations. Nature 2019, 569 (7757), 546-550.
4. Davies, H.; Bignell, G. R.; Cox, C.; Stephens, P.; Edkins, S.; Clegg, S.; Teague, J.; Woffendin, H.; Garnett, M. J.; Bottomley, W., Mutations of the BRAF gene in human cancer. Nature 2002, 417 (6892), 949-954.
5. Trichet, V.; Grelier, S.; Castellan, A.; Choudhury, H.; Davidson, R. S., Attempt to photostabilize paper made from high-yield pulp by application of UV screens in conjunction with thiols. Journal of Photochemistry and Photobiology A: Chemistry 1996, 95 (2), 181-188.
6. Valet, A., Outdoor applications of UV curable clearcoats-a real alternative to thermally cured clearcoats. Progress in organic coatings 1999, 35 (1-4), 223-233.
7. Lee, B.-H.; Kim, H.-J., Influence of isocyanate type of acrylated urethane oligomer and of additives on weathering of UV-cured films. Polymer Degradation and Stability 2006, 91 (5), 1025-1035.
8. Serpone, N.; Salinaro, A., Terminology, relative photonic efficiencies and quantum yields in heterogeneous photocatalysis. Part I: Suggested protocol. Pure and Applied Chemistry 1999, 71 (2), 303-320.
9. Salinaro, A.; Emeline, A. V.; Zhao, J.; Hidaka, H.; Ryabchuk, V. K.; Serpone, N., Terminology, relative photonic efficiencies and quantum yields in heterogeneous photocatalysis. Part II: Experimental determination of quantum yields. Pure and applied chemistry 1999, 71 (2), 321-335.
10. Morabito, K.; Shapley, N.; Steeley, K.; Tripathi, A., Review of sunscreen and the emergence of non‐conventional absorbers and their applications in ultraviolet protection. International journal of cosmetic science 2011, 33 (5), 385-390.
11. Food; Administration, D., Sunscreen drug products for over the counter human use: final monograph. Federal register, US 1999, 27666-27693.
12. Serpone, N.; Dondi, D.; Albini, A., Inorganic and organic UV filters: Their role and efficacy in sunscreens and suncare products. Inorganica chimica acta 2007, 360 (3), 794-802.
13. Fujita, T.; Yutaka, K.; Abe, N.; Akamatsu, T., Tetrahydrophthalimide methyl-2-phenylbenzatriazoles. Google Patents: 1978.
14. Pei, K.; Cui, Z.; Chen, W., An adduct of Cl-substituted benzotriazole and hydroxy benzophenone as a novel UVA/UVB absorber: Theory-guided design, synthesis, and calculations. Journal of Molecular Structure 2013, 1032, 100-104.
15. 郭振宇; 刘丽湘; 丁著明, 耐候性聚氨酯的研究进展. 2005 塑料助剂生产与应用技术信息交流会论文集 2005.
16. 丁著明; 张金国, 聚合物材料稳定剂 UV—326 的生产和应用. 化工新型材料 2000, 28 (7), 22-25.
17. 李学安; 丁著明, 紫外线吸收剂 UV—326 小试通过审议. 精细石油化工 1986, (4), 12.
18. Kim, B. H.; Lee, Y. S.; Kwon, W.; Jin, Y.; Tak, J. A.; Jun, Y. M.; Baik, W.; Lee, B. M., 2‐Bromo‐2‐nitropropane/Zn Promoted Reductive Cyclizations of ortho‐Carbonyl, Imino, or Azo Substituted Nitrobenzenes. ChemInform 1999, 30 (17), no-no.
19. Baik, W.; Park, T. H.; Kim, B. H.; Jun, Y. M., Reductive Cyclization of o-Nitrophenylazo Dyes Using Bakers' Yeast in NaOH Solution. A New Synthesis of 2-Aryl-2H-benzotriazoles and Their 1-Oxides. The Journal of Organic Chemistry 1995, 60 (17), 5683-5685.
20. Lefedova, O., Hydrogenation kinetics of 2′-hydroxy-5′-methyl-2-nitroazobenzene under quasisteady conditions. Russian Journal of Physical Chemistry A 2003, 77 (8), 1266-1269.
21. Liu, G. B.; Zhao, H. Y.; Yang, H. J.; Gao, X.; Li, M. K.; Thiemann, T., Preparation of 2‐Aryl‐2H‐benzotriazoles by Zinc‐Mediated Reductive Cyclization of o‐Nitrophenylazophenols in Aqueous Media without the Use of Organic Solvents. Advanced Synthesis & Catalysis 2007, 349 (10), 1637-1640.
22. Farkas, R.; Törincsi, M.; Kolonits, P.; Alonso, O. J.; Novak, L., One-pot synthesis of benzotriazoles and benzotriazole 1-oxides by reductive cyclization of o-nitrophenylazo compounds with benzyl alcohol. Heterocycles 2009, 78 (10), 2579-2588.
23. Nugent, W. A.; Harlow, R. L., Early transition metal alkoxide complexes bearing homochiral trialkanolamine ligands. Journal of the American Chemical Society 1994, 116 (14), 6142-6148.
24. Slater, J. C., The self-consistent field for molecules and solids. McGraw-Hill: 1974; Vol. 4.
25. Vogl, O.; Albertsson, A. C.; Janovic, Z., New developments in speciality polymers: polymeric stabilizers. Polymer 1985, 26 (9), 1288-1296.
26. Aultz, D., Development on Polymeric Benzotriazole Stabilizer. Spec. Chem 1996, 16 (71), 73-74.
27. Skoog, D. A.; Holler, F. J.; Nieman, T., Principles of instrumental analysis. 5th. Thomson Learning, USA, p849 1998.
28. Weber, K., Close connection between extinction of fluorescence and retardation of photochemical reactions. Z. physik. Chem 1931, 15, 18-44.
29. Weller, A., Quantitative untersuchungen der fluoreszenzumwandlung bei naphtholen. Zeitschrift für Elektrochemie, Berichte der Bunsengesellschaft für physikalische Chemie 1952, 56 (7), 662-668.
30. Weller, A., A generalized theory of diffusion determined reactions and its applications to the fluorescence excitation. Z. Phys. Chem. NF 1957, 13, 335-352.
31. Weller, A., Protolytische reaktionen angeregter oxyverbindungen. Zeitschrift für Physikalische Chemie 1958, 17 (3_4), 224-245.
32. Weller, A., Zur kinetik der fluoreszenzumwandlung. Zeitschrift für physikalische Chemie 1958, 15 (1-6), 438-453.
33. Förster, T., Diabatic and adiabatic processes in photochemistry. Pure Appl. Chem 1970, 24 (3), 443-450.
34. Weller, A., Fast reactions of excited molecules. Progress in reaction kinetics and mechanism 1961, 1, 187-&.
35. Beens, H.; Grellmann, K.; Gurr, M.; Weller, A., Effect of solvent and temperature on proton transfer reactions of excited molecules. Discussions of the Faraday Society 1965, 39, 183-193.
36. Parthenopoulos, D. A.; McMorrow, D. P.; Kasha, M., Comparative study of stimulated proton-transfer luminescence of three chromones. The Journal of Physical Chemistry 1991, 95 (7), 2668-2674.
37. Sobolewski, A. L.; Domcke, W., Photophysics of intramolecularly hydrogen-bonded aromatic systems: ab initio exploration of the excited-state deactivation mechanisms of salicylic acid. Physical Chemistry Chemical Physics 2006, 8 (29), 3410-3417.
38. Lim, S.-J.; Seo, J.; Park, S. Y., Photochromic switching of excited-state intramolecular proton-transfer (ESIPT) fluorescence: a unique route to high-contrast memory switching and nondestructive readout. Journal of the American Chemical Society 2006, 128 (45), 14542-14547.
39. Ash, S.; Beg, H.; Mazumdar, P.; Salgado-Morán, G.; Misra, A., Polarizability, hardness and electrophilicity as global descriptors for intramolecular proton transfer reaction path. Computational and Theoretical Chemistry 2014, 1031, 50-55.
40. Organero, J. A.; Moreno, M.; Santos, L.; Lluch, J. M.; Douhal, A., Photoinduced proton transfer and rotational motion of 1-hydroxy-2-acetonaphthone in the S1 state: A theoretical insight into its photophysics. The Journal of Physical Chemistry A 2000, 104 (36), 8424-8431.
41. Catalán, J.; De Paz, J., Comment on “Photoinduced Proton Transfer and Rotational Motion of 1-Hydroxy-2-acetonaphthone in the S1 State: A Theoretical Insight into Its Photophysics”(J. Phys. Chem. A 2000, 104, 8424). The Journal of Physical Chemistry A 2001, 105 (30), 7315-7316.
42. Yahagi, T.; Fujii, A.; Ebata, T.; Mikami, N., Infrared spectroscopy of the OH stretching vibrations of jet-cooled salicylic acid and its dimer in S0 and S1. The Journal of Physical Chemistry A 2001, 105 (47), 10673-10680.
43. Chowdhury, P.; Panja, S.; Chakravorti, S., Excited state prototropic activities in 2-hydroxy 1-naphthaldehyde. The Journal of Physical Chemistry A 2003, 107 (1), 83-90.
44. Paul, B. K.; Samanta, A.; Guchhait, N., Deciphering the photophysics of 5-chlorosalicylic acid: evidence for excited-state intramolecular proton transfer. Photochemical & Photobiological Sciences 2010, 9 (1), 57-67.
45. Crawford, J., Prog. Polym. Sci. 1999.
46. Rosevear, J.; Wilshire, J., Preparation of some 2-(2'H-Benzotriazol-2'-yl) phenol ultraviolet absorbers: application of the transalkylation reaction. Australian journal of chemistry 1985, 38 (8), 1163-1176.
47. Kocher, C.; Weder, C.; Smith, P., ‘Latent’ultraviolet light absorbers. Journal of Materials Chemistry 2003, 13 (1), 9-15.
48. Fores, M.; Scheiner, S., Effects of chemical substitution upon excited state proton transfer. Fluoroderivatives of salicylaldimine. Chemical physics 1999, 246 (1-3), 65-74.
49. Maliakal, A.; Lem, G.; Turro, N. J.; Ravichandran, R.; Suhadolnik, J. C.; DeBellis, A. D.; Wood, M. G.; Lau, J., Twisted intramolecular charge transfer states in 2-arylbenzotriazoles: fluorescence deactivation via intramolecular electron transfer rather than proton transfer. The Journal of Physical Chemistry A 2002, 106 (34), 7680-7689.
50. Lu, Y.; Gong, Y.; Ma, H.; Wang, Z.; Li, H.; Luo, Z.; Li, H.; Gao, F., 4-Formyl-2-(2H-benzotriazol-2-yl)-phenol: an ESIPT chromophore. Chinese science bulletin 2014, 59 (34), 4741-4751.