Insights into ultrafast decay dynamics of electronically excited pyridine-N-oxide

Feng, Baihui1,2,3; Wu, Wenping1,3; Yang, Shuaikang1,4; He, Zhigang1; Fang, Benjie2; Yang, Dongyuan1; Wu, Guorong1; Yang, Xueming1,5

2024-03-06

10.1039/d3cp06187f

PHYSICAL CHEMISTRY CHEMICAL PHYSICS   影响因子和分区

1463-9076

1463-9084

The ultrafast decay dynamics of pyridine-N-oxide upon excitation in the near-ultraviolet range of 340.2-217.6 nm is investigated using the femtosecond time-resolved photoelectron imaging technique. The time-resolved photoelectron spectra and photoelectron angular distributions at all pump wavelengths are carefully analyzed and the following view is derived: at the longest pump wavelengths (340.2 and 325.6 nm), pyridine-N-oxide is excited to the S-1((1)pi pi*) state with different vibrational levels. The depopulation rate of the S-1 state shows a marked dependence on vibrational energy and mode, and the lifetime is in the range of 1.4-160 ps. At 289.8 and 280.5 nm, both the second (1)pi pi* state and the S-1 state are initially prepared. The former has an extremely short lifetime of similar to 60 fs, which indicates that the ultrafast deactivation pathway such as a rapid internal conversion to one close-lying state is its dominant decay channel, while the latter is at high levels of vibrational excitation and decays within the range of 380-520 fs. At the shortest pump wavelengths (227.3 and 217.6 nm), another excited state of Rydberg character is mostly excited. We assign this state to the 3s Rydberg state which has a lifetime of 0.55-2.2 ps. This study provides a comprehensive picture of the ultrafast excited-state decay dynamics of the photoexcited pyridine-N-oxide molecule.

SCI ; EI

英语

其他

National Natural Science Foundation of China["22203095","22103087","21833003","22288201"] ; National Natural Science Foundation of China[GJJSTD20220001]

Chemistry ; Physics

Chemistry, Physical ; Physics, Atomic, Molecular & Chemical

WOS:001174581200001

ROYAL SOC CHEMISTRY

CHEMISTRY

Web of Science

1.Dalian Inst Chem Phys, Chinese Acad Sci, State Key Lab Mol React Dynam, 457 Zhongshan Rd, Dalian 116023, Liaoning, Peoples R China
2.Chinese Acad Sci, Dalian Inst Chem Phys, Key Lab Chem Lasers, 457 Zhongshan Rd, Dalian 116023, Liaoning, Peoples R China
3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
4.Univ Sci & Technol China, Dept Chem Phys, Hefei 230026, Anhui, Peoples R China
5.Southern Univ Sci & Technol, Coll Sci, Dept Chem, Shenzhen 518055, Peoples R China

Feng, Baihui,Wu, Wenping,Yang, Shuaikang,et al. Insights into ultrafast decay dynamics of electronically excited pyridine-N-oxide[J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2024,26(10).

Feng, Baihui.,Wu, Wenping.,Yang, Shuaikang.,He, Zhigang.,Fang, Benjie.,...&Yang, Xueming.(2024).Insights into ultrafast decay dynamics of electronically excited pyridine-N-oxide.PHYSICAL CHEMISTRY CHEMICAL PHYSICS,26(10).

Feng, Baihui,et al."Insights into ultrafast decay dynamics of electronically excited pyridine-N-oxide".PHYSICAL CHEMISTRY CHEMICAL PHYSICS 26.10(2024).