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771.
772.
Kao WF 《Physical review D: Particles and fields》1990,42(12):4159-4164
773.
Chen HY Yeh SW Hsu SC Kao CL Dong TY 《Physical chemistry chemical physics : PCCP》2011,13(7):2674-2681
The formation of base pair radical anions is closely related to many fascinating research fields in biology and chemistry such as radiation damage to DNA and electron transport in DNA. However, the relevant knowledge so far mainly comes from studies on isolated base pair radical anions, and their behavior in the DNA environment is less understood. In this study, we focus on how the nucleobase sequence affects the properties of the guanine-cytosine (GC) base pair radical anion. The energetic barrier and reaction energy for the proton transfer along the N(1)(G)-H···N(3)(C) hydrogen bond and the stability of GC˙(-) (i.e., electron affinity of GC) embedded in different sequences of base-pair trimer were evaluated using density functional theory. The computational results demonstrated that the presence of neighboring base pairs has an important influence on the behavior of GC˙(-) in the gas phase. The excess electron was found to be localized on the embedded GC and the charge leakage to neighboring base pairs was very minor in all of the investigated sequences. Accordingly, the sequence behavior of the proton-transfer reaction and the stability of GC˙(-) is chiefly governed by electrostatic interactions with adjacent base pairs. However, the effect of base stacking, due to its electrostatic nature, is severely screened upon hydration, and thus, the sequence dependence of the properties of GC˙(-) in aqueous environment becomes relatively weak and less than that observed in the gas phase. The effect of geometry relaxation associated with neighboring base pairs as well as the possibility of proton transfer along the N(2)(G)-H···O(2)(C) channel have also been investigated. The implications of the present findings to the electron transport and radiation damage of DNA are discussed. 相似文献
774.
775.
Dr. Li-Wei Lee Heng-Yu Chi Ya-Chuan Kao Ting-Hsiang Hung Da-Shiuan Chiou Gene-Hsiang Lee Prof. Shie-Ming Peng Prof. Dun-Yen Kang Prof. Chih-Min Wang Prof. Kuang-Lieh Lu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(19):4204-4208
Multiple-stimuli-responsive photoluminescence films based on a ZnII–organic framework, {[Zn2(Htpim)(3,4-pydc)2] ⋅ 4 DMF ⋅ 4 H2O}n ( 1 , Htpim=2,4,5-tri(4-pyridyl)imidazole, 3,4-H2pydc=3,4-pyridinedicarboxylic acid), were fabricated. This compound consisted of a 2D corrugated layer, {Zn(3,4-pydc)}n, which was further pillared using a Y-shaped pillar N-donor ligand (Htpim) to form a 3D-pillared-layer framework with 1D open channels. The rectangular channels in the as-synthesized compound are fully occupied by guest DMF and H2O molecules. The framework exhibits instant and reversible thermochromic properties corresponding to the removal of different H2O and DMF guest molecules as temperature increases. The pale-yellow crystal undergoes significant redshifting to a greenish emission centered at 530 nm. Compound 1 also showed remarkable solvatochromic effects in the presence of various organic solvents without affecting its structural integrity. In addition, polycrystalline MOF films were grown on an α-Al2O3 support for switchable and fast-response thermochromic and solvatochromic sensors. 相似文献