Unimolecular Dissociation Dynamics of Electronically Excited Hco(Ã2a′′): Rotational Control of Nonadiabatic Decay

Abstract

The photoinduced unimolecular decay of the electronically excited HCO(Ã2A′′) is investigated in a combined experimental-theoretical study. The molecule is excited to the (1, n2, 0) combination bands, which decay via Renner-Teller coupling to the ground electronic state. The rovibrational state distribution of the CO fragment was measured via the high-n Rydberg H-atom time-of-flight method and calculated using a wave packet method on an accurate set of potential energy surfaces. It is shown that the non-adiabatic decay rate is strongly modulated by the HCO rotational angular momentum, which leaves unique signatures in the product state distribution. The experimentally observed bimodal rotational distribution of the dominant CO(v = 0) fragment is likely due to decay of different vibronic states populated by the excitation and modulated by the excited state lifetime, which is in turn controlled by the parent rotational quantum number.

Department(s)

Chemistry

Comments

National Science Foundation, Grant GXXT 2020-004

International Standard Serial Number (ISSN)

1364-5498; 1359-6640

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Royal Society of Chemistry, All rights reserved.

Publication Date

24 Mar 2022

PubMed ID

35781478

Link to Full Text

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