Photodimerization of Thymine Derivatives in Single Crystal.

Tohnai, Norimitsu; Miyata, Mikiji; Yasui, Norio; Mochizuki, Eiko; Inaki, Yoshiaki

doi:10.2494/photopolymer.11.59

Cited by 24 publications

(27 citation statements)

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“…Optimum photodimerization was reached when the alkyl chain possessed between eight and twelve carbon units. Such a chain length results in a mixture of crystalline and amorphous character in the film, which permits the thymine bases to move into the stacked orientation that is preferred for photodimerization [104,105]. Two isomers of the thymine photodimer (cis-syn and trans-syn) can be obtained by UV irradiation of N 1 -alkylthymine in the solid spin-cast state.…”

Section: Photochemistry Photochromism and Pyrimidinementioning

confidence: 98%

Functionalized gold nanoparticles: Synthesis, structure and colloid stability

Zhou

Ralston

Sedev

et al. 2009

Journal of Colloid and Interface Science

371

223

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Section: Photochemistry Photochromism and Pyrimidinementioning

confidence: 98%

Functionalized gold nanoparticles: Synthesis, structure and colloid stability

Zhou

Ralston

Sedev

et al. 2009

Journal of Colloid and Interface Science

371

223

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“…Thymine bases in the single crystal are necessary to rotate for the formation of photodimer. 14 Figure 18 shows the nearest two molecules in the crystal for C13 and Rll. The thymine base in the crystal obtained from acetonitrile (Rll) rotates during photodimerization, because the crystal contains acetonitrile molecules and the terminal methyl group is very far from the thymine base …”

Section: Crystal Structure and Photodimerization Of Thymine Compoundsmentioning

confidence: 99%

Reversible Photodimerization of Ester Derivatives of Thymine Having Long Alkyl Chains in Solid Film

Mochizuki

Tohnai

Wang

et al. 2000

Polym J

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ABSTRACT:Reversible photodimerizations of ester derivatives of thymine having long alkyl chains were studied in thin solid film. The spin coated thin film of thymine compounds gave the photodimer under irradiation of UV light at 280 nm, and photodimers gave original thymine compounds by UV irradiation at 240 nm. The rates of photodimerization in thin solid film increased with length of the alkyl chain, followed by decrease when the carbon number of the alkyl chain was above 13. The behavior of photodimerization depended on the carbon number of the alkyl chains. The structures of the thymine derivatives in thin solid film were estimated from the data of differential thermal analysis, powder X-ray diffraction, and crystal structure of the single crystal. The layer structures of thymines and alkyl chains were concluded to be the reason for photoactivity in thin solid film. When the carbon numbers of the alkyl chains were 12 and 13, the photodimerizations were fast in the thin solid film, but diminished by annealing of the film. The reason for this was the formation of the inactive micro crystals by annealing.KEY WORDS Thymine/ Photodimerization / Photosplitting / Differential Scanning Calorimetry/ Powder X-Ray Diffraction/ Crystal Structure/ Solid Film/ DNA is damaged by irradiation of UV light. Photoactive nucleic acid bases are pyrimidine bases such as thymine, cytosine and uracil, but purine bases are stable toward UV irradiation. I The photodimerization of thymine is reversible depending on wavelength of irradiating UV light, although photodimerization of uracil is irreversible ( Figure 1).2 Polymer and monomer derivatives of thymine may thus be used as reversible photosensitive materials such as reversible photoresists and reversible photo-recording systems. -8The intermolecular photodimerization of thymine bases grafted onto the side chain ofpolymethacrylate led to photocrosslinking of the polymers, thus allowing them to be applied as negative type photoresists.9 The orientation of thymine bases was found important for intermolecular photodimerization in preference to the intramolecular one. Bis-thymine compounds where two thymines were connected by ester or amide bonds were also negative type photoresists, because the photodimerization of thymine bases gave the polymers in solid film_ Io For photodimerization of the bis-thymine compounds in solution, however, the main photoproduct was the cyclic photodimer. The conformation of the bis-thymine com- pounds was concluded to be an important factor for photodimerization. Polyamides and polyesters containing thymine photodimers in the main chain were negative type photoresists. 11 -I 2 Irradiation of UV light at short wavelength (240 nm) on these polymers gave low molecular weight compounds containing thymine bases soluble in alkaline aqueous solution.For high sensitive and completely reversible photoactive materials, it is necessary to study reversible photodimerization and conformations of the thymine derivatives in solid film. There are troublesome problems for...

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“…The reversible photodimerizations are applicable to photoresists and reversible photorecording materials.2' 3) Crystal structure and photodimerizations have been studied for 1-alkylthymine derivatives to clear mechanism of photodimerization in solid state. [4][5][6][7][8][9][10][11] polymorphism was found in crystals of 1-alkylthymines. Crystal structure was found to affect on photodimerization of thymine bases in crystals.…”

Section: Introductionmentioning

confidence: 99%

Crystal Structure and Photodimerization of 1-Alkylthymine: Effect of Long Alkyl Chain on Isomer Ratio of Photodimer.

Inaki¹,

Mochizuki

Yasui

et al. 2000

J. Photopol. Sci. Technol.

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Crystal structure and photodimerization of 1-alkylthymine were studied in single crystals. Length of alkyl chains in 1-alkylthymine affected on crystal structure and photodimerization in single crystal. l-Alkylthymine gave two types of crystals,Type 1 and Type 2 depending on length of alkyl chains and solvent used. This paper deals with Type 1 crystal, where thymine bases form plates by hydrogen bonding. UV irradiation at 280 nm on Type 1 crystals of 1-alkylthymine gave cyclobutane type photodimers. Crystals of 1-pentylthymine (C5), 1-nonylthymine (C9), and 1-decylthymine (C10) gave a trans-syn photodimer, but 1-octylthymine (C8) crystal gave a trans-anti photodimer. Alkyl chains played an important role in forming different isomers of photodimers.

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Photodimerization of Thymine Derivatives in Single Crystal.

Cited by 24 publications

References 0 publications

Functionalized gold nanoparticles: Synthesis, structure and colloid stability

Functionalized gold nanoparticles: Synthesis, structure and colloid stability

Reversible Photodimerization of Ester Derivatives of Thymine Having Long Alkyl Chains in Solid Film

Crystal Structure and Photodimerization of 1-Alkylthymine: Effect of Long Alkyl Chain on Isomer Ratio of Photodimer.

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