The methyl- and aza-substituent effects on nonradiative decay mechanisms of uracil in water: a transient absorption study in the UV region

CORC > 武汉物理与数学研究所 > 中国科学院武汉物理与数学研究所 > 原子分子光物理研究部

	The methyl- and aza-substituent effects on nonradiative decay mechanisms of uracil in water: a transient absorption study in the UV region
	Hua, XinZhong 1,2; Hua, LinQiang 1; Liu, XiaoJun 1
刊名	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
	2016-05-28
卷号	18 期号:20 页码:13904-13911
英文摘要	The nonradiative decay dynamics of photo-excited uracil (Ura) and its derivatives, i.e., thymine (5-methyluracil, Thy), 6-methyluracil (6-MU) and 6-azauracil (6-AU) in water, has been studied using a femtosecond transient absorption method. The molecules are populated in the lowest (1)pi pi(star) state by a pump pulse at 266 nm, and a broadband continuum in the deep UV region is then employed as the probe. The extension of the continuous UV probe down to 250 nm enables us to investigate comprehensively the population dynamics of the ground states for those molecules and to uncover the substituent effects on nonradiative decay dynamics of uracil. Vibrational cooling in the ground states of Ura, Thy and 6-MU has been directly observed for the first time, providing solid evidence of the ultrafast (1)pi pi(star) -> S-0 decay. In combination with the ground state bleaching signals, it is consolidated that their lowest (1)pi pi(star) state decays via two parallel pathways, i.e., (1)pi pi(star) -> S-0 and (1)pi pi(star) -> (1)n pi(star). Moreover, the contribution of the (1)pi pi(star) -> (1)n pi(star) channel is found to be much smaller for Thy or 6-MU than for Ura. Different from methyl-substitution, the initial (1)pi pi(star) state of the aza-substituent 6-AU decays primarily to the (1)n pi(star) state, while the (1)pi pi(star) -> S-0 channel can be negligible. Our study provides a comprehensive understanding of the substituent effects on the excited-state dynamics of uracil in water.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Chemistry, Physical ; Physics, Atomic, Molecular & Chemical
研究领域[WOS]	Chemistry ; Physics
关键词[WOS]	STATE STRUCTURAL DYNAMICS ; FLUORESCENCE UP-CONVERSION ; ULTRAFAST INTERNAL-CONVERSION ; RESONANCE RAMAN-SPECTROSCOPY ; ELECTRONIC GROUND-STATE ; EXCITED-STATE ; CONICAL INTERSECTIONS ; RADIATIONLESS DECAY ; PYRIMIDINE-BASES ; AQUEOUS-SOLUTION
收录类别	SCI
语种	英语
WOS记录号	WOS:000377042400019
内容类型	期刊论文
源URL	[http://ir.wipm.ac.cn/handle/112942/9375]
专题	武汉物理与数学研究所_原子分子光物理研究部
作者单位	1.Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Hua, XinZhong,Hua, LinQiang,Liu, XiaoJun. The methyl- and aza-substituent effects on nonradiative decay mechanisms of uracil in water: a transient absorption study in the UV region[J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2016,18(20):13904-13911.
APA	Hua, XinZhong,Hua, LinQiang,&Liu, XiaoJun.(2016).The methyl- and aza-substituent effects on nonradiative decay mechanisms of uracil in water: a transient absorption study in the UV region.PHYSICAL CHEMISTRY CHEMICAL PHYSICS,18(20),13904-13911.
MLA	Hua, XinZhong,et al."The methyl- and aza-substituent effects on nonradiative decay mechanisms of uracil in water: a transient absorption study in the UV region".PHYSICAL CHEMISTRY CHEMICAL PHYSICS 18.20(2016):13904-13911.