Back to Search Start Over

Collision induced state-to-state energy transfer dynamics between the 2u (1D2) and 2g (1D2) ion-pair states of I2.

Authors :
Hoshino, Shoma
Nakano, Yukio
Araki, Mitsunori
Ishiwata, Takashi
Tsukiyama, Koichi
Source :
Physical Chemistry Chemical Physics (PCCP); 6/7/2016, Vol. 18 Issue 21, p14292-14298, 7p
Publication Year :
2016

Abstract

We report the first observation of collision induced state-to-state energy transfer from the 2<subscript>u</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) (v<subscript>2<subscript>u</subscript></subscript> = 3–7) ion-pair state of I<subscript>2</subscript> using a perturbation facilitated optical–optical double resonance technique through the c <superscript>1</superscript>Π<subscript>g</subscript>∼ B <superscript>3</superscript>Π(0+u) hyperfine mixed double-faced valence state as the intermediate state. The excitation of the 2<subscript>u</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) state yielded the weak UV fluorescence from the wide range of vibrational levels in the nearby 2<subscript>g</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) state. The vibrational distribution in the 2<subscript>g</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) state derived by the Franck–Condon simulation of the UV fluorescence showed that the population in the 2<subscript>u</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) state transfers mostly to the 2<subscript>g</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) vibronic levels which are located energetically above the laser-prepared level. The radiative lifetimes and the self-quenching rate constants were determined to be 21.3 ± 0.1 and 44.6 ± 0.8 ns, and (1.30 ± 0.01) × 10<superscript>−9</superscript> and (2.26 ± 0.17) × 10<superscript>−9</superscript> cm<superscript>3</superscript> molecule<superscript>−1</superscript> s<superscript>−1</superscript> for the 2<subscript>u</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) (v<subscript>2<subscript>u</subscript></subscript> = 3) and 2<subscript>g</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) (v<subscript>2<subscript>g</subscript></subscript> = 5) states, respectively. The rate constant for the 2<subscript>u</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) – 2<subscript>g</subscript> (<superscript>1</superscript>D<subscript>2</subscript>) collision induced state-to-state energy transfer was also evaluated to be (1.89 ± 0.01), (3.07 ± 0.07), and (3.77 ± 0.05) × 10<superscript>−10</superscript> cm<superscript>3</superscript> molecule<superscript>−1</superscript> s<superscript>−1</superscript> for the v<subscript>2<subscript>u</subscript></subscript> = 3, 5, and 7 levels, respectively. The very large self-quenching cross sections for the ion-pair states of I<subscript>2</subscript> could be explained by the harpoon mechanism. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
14639076
Volume :
18
Issue :
21
Database :
Complementary Index
Journal :
Physical Chemistry Chemical Physics (PCCP)
Publication Type :
Academic Journal
Accession number :
115676552
Full Text :
https://doi.org/10.1039/c6cp00222f