Details
Original language | English |
---|---|
Pages (from-to) | 505-515 |
Number of pages | 11 |
Journal | Canadian journal of chemistry |
Volume | 101 |
Issue number | 8 |
Publication status | Published - Aug 2023 |
Externally published | Yes |
Abstract
Although the krypton dimer, Kr2, is a prototypical weakly bound van der Waals complex in its ground electronic state, the excited states of Kr2 exhibit many and various interactions. Resonance-enhanced multiphoton ionization and velocity map imaging provide an avenue to explore the electronic structure and photofragmentation dynamics of Kr2 in the vacuum ultraviolet region. By monitoring photofragmentation product channels and recoil anisotropy distributions, one can gain insights into excited state symmetries and lifetimes, which can aid in interpreting spectroscopy. Here, we study the spectroscopy and photodissociation dynamics of Kr2 in the 91 000–94 500 cm−1 region. We record and assign photofragment product channels for 32 vibronic bands corresponding to seven electronic transitions. We also identify two previously unobserved vibronic band systems, which we assign as the Kr2 5p [5/2]3 1g ← X0+gand 5p [3/2]20+g←X0+g transitions. Velocity map images show photofragments arising from predissociation of the neutral Rydberg states and from dissociative photoionization at the n > 2 photon level. We also observe variation in branching ratios between the predissociative and dissociative photoionization channels depending on the lifetime of the intermediate; longer lived states favour higher dissociative photoionization yields and exhibit β6 anisotropy parameters for predissociation product channels, indicating “rotational smearing” of the product angular distributions.
Keywords
- krypton dimer, photofragment imaging, REMPI spectroscopy, Rydberg states, time-of-flight spectrometry, VMI
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Chemistry(all)
- Chemistry(all)
- Organic Chemistry
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In: Canadian journal of chemistry, Vol. 101, No. 8, 08.2023, p. 505-515.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Investigating the Rydberg states and photodissociation dynamics of Kr2 using velocity map imaging
AU - Stienstra, Cailum M.K.
AU - Coughlan, Neville J.A.
AU - Haack, Alexander
AU - Carr, Patrick J.J.
AU - Crouse, Jeff
AU - Featherstone, Joshua
AU - Scott Hopkins, W.
N1 - Funding Information: WSH acknowledges funding from the Canadian Foundation for Innovation (CFI), Ontario Research Fund (ORF), and Natural Sciences and Engineering Research Council (NSERC) of Canada in the form of a Discovery Grant. CMKS acknowledges financial support from NSERC in the form of a Canadian Graduate Scholarship. NJAC acknowledges financial support from the NSERC Banting postdoctoral fellowship program. AH gratefully acknowledges this work being funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation; 449651261). Canadian Foundation for Innovation, Ontario Research Fund, Natural Sciences and Engineering Research Council of Canada, Deutsche Forschungsgemeinschaft (DFG; German Research Foundation).
PY - 2023/8
Y1 - 2023/8
N2 - Although the krypton dimer, Kr2, is a prototypical weakly bound van der Waals complex in its ground electronic state, the excited states of Kr2 exhibit many and various interactions. Resonance-enhanced multiphoton ionization and velocity map imaging provide an avenue to explore the electronic structure and photofragmentation dynamics of Kr2 in the vacuum ultraviolet region. By monitoring photofragmentation product channels and recoil anisotropy distributions, one can gain insights into excited state symmetries and lifetimes, which can aid in interpreting spectroscopy. Here, we study the spectroscopy and photodissociation dynamics of Kr2 in the 91 000–94 500 cm−1 region. We record and assign photofragment product channels for 32 vibronic bands corresponding to seven electronic transitions. We also identify two previously unobserved vibronic band systems, which we assign as the Kr2 5p [5/2]3 1g ← X0+gand 5p [3/2]20+g←X0+g transitions. Velocity map images show photofragments arising from predissociation of the neutral Rydberg states and from dissociative photoionization at the n > 2 photon level. We also observe variation in branching ratios between the predissociative and dissociative photoionization channels depending on the lifetime of the intermediate; longer lived states favour higher dissociative photoionization yields and exhibit β6 anisotropy parameters for predissociation product channels, indicating “rotational smearing” of the product angular distributions.
AB - Although the krypton dimer, Kr2, is a prototypical weakly bound van der Waals complex in its ground electronic state, the excited states of Kr2 exhibit many and various interactions. Resonance-enhanced multiphoton ionization and velocity map imaging provide an avenue to explore the electronic structure and photofragmentation dynamics of Kr2 in the vacuum ultraviolet region. By monitoring photofragmentation product channels and recoil anisotropy distributions, one can gain insights into excited state symmetries and lifetimes, which can aid in interpreting spectroscopy. Here, we study the spectroscopy and photodissociation dynamics of Kr2 in the 91 000–94 500 cm−1 region. We record and assign photofragment product channels for 32 vibronic bands corresponding to seven electronic transitions. We also identify two previously unobserved vibronic band systems, which we assign as the Kr2 5p [5/2]3 1g ← X0+gand 5p [3/2]20+g←X0+g transitions. Velocity map images show photofragments arising from predissociation of the neutral Rydberg states and from dissociative photoionization at the n > 2 photon level. We also observe variation in branching ratios between the predissociative and dissociative photoionization channels depending on the lifetime of the intermediate; longer lived states favour higher dissociative photoionization yields and exhibit β6 anisotropy parameters for predissociation product channels, indicating “rotational smearing” of the product angular distributions.
KW - krypton dimer
KW - photofragment imaging
KW - REMPI spectroscopy
KW - Rydberg states
KW - time-of-flight spectrometry
KW - VMI
UR - http://www.scopus.com/inward/record.url?scp=85167823457&partnerID=8YFLogxK
U2 - 10.1139/cjc-2022-0283
DO - 10.1139/cjc-2022-0283
M3 - Article
AN - SCOPUS:85167823457
VL - 101
SP - 505
EP - 515
JO - Canadian journal of chemistry
JF - Canadian journal of chemistry
SN - 0008-4042
IS - 8
ER -