Imaging studies of the CH3 fragments formed in the ultraviolet photodissociation of dimethylamine: Role of the parent 3s and 3p Rydberg states

Wangchingchai, Peerapat; Yamasaki, Katsuyoshi; Kohguchi, Hiroshi

doi:10.1016/j.cplett.2022.139671

Cited by 1 publication

(3 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental procedures were similar to those used in our previous MA, DMA, and TMA studies. We diluted commercially available 10% DMA/He gas (Taiyo Nippon Sanso) to 1% for the measurements without further purification.…”

Section: Experimental and Theoretical Methodsmentioning

confidence: 99%

“…The S 1 and S 2 photodissociation of DMA was investigated in our previous study, in which the CH 3 products in the vibrational ground state (v = 0) were measured by ion imaging. 29 The translational energy distribution depended on the photolysis wavelength (λ photolysis ) and exhibited two translational energy components with the threshold λ photolysis near 225 nm. Combined with preliminary PES calculations using the optimized DMA cation structure for the Rydberg excited states, we propose two N−CH 3 dissociation pathways.…”

Section: Introductionmentioning

confidence: 99%

“…Dimethylamine ((CH 3 ) 2 NH: DMA), which consists of a single N–H and two N–C bonds, is a molecule that is key to understanding the competition between the N–H/N–C dissociation and the roles of the S 1 /S 2 excited states in alkyl amine photochemistry. , The S 2 state, which has not been extensively studied in NH 3 and MA because of the need for a sub-200 nm photolysis light source, is optically accessible by DMA in standard laser-based dynamics experiments. The S 1 and S 2 photodissociation of DMA was investigated in our previous study, in which the CH 3 products in the vibrational ground state ( v = 0) were measured by ion imaging . The translational energy distribution depended on the photolysis wavelength (λ photolysis ) and exhibited two translational energy components with the threshold λ photolysis near 225 nm.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

N–H and N–C Bond Dissociation Pathways in Ultraviolet Photodissociation of Dimethylamine

Wangchingchai,

Karino,

Yamasaki

et al. 2024

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

We investigated the interlinked N−H and N−C photochemistry of primary and secondary amines via the state-resolved detection of vibrationally excited CH 3 product and H atom product by 200−235 nm dimethylamine photodissociation using resonance-enhanced multiphoton ionization (REMPI) and velocity map imaging (VMI) techniques. The out-of-plane bending (ν 2 ) vibrationally excited CH 3 showed a bimodal translational energy distribution that became unimodal with a near-zero product yield at longer photolysis wavelengths (λ photolysis ). In contrast, a unimodal distribution was observed for the C−H stretching (ν CH ) vibrationally excited CH 3 products with an almost constant product yield in the examined λ photolysis region. We ascribed the state-specific energy releases of the CH 3 products to two reaction pathways based on calculations of the potential energy surface (PES): the direct N−CH 3 dissociation pathway and the indirect N−CH 3 dissociation pathway via the N−H bond conical intersection. Meanwhile, the H atom product showed a bimodal energy distribution similar to the ammonia photodissociation model, with an excited-state counterproduct channel that became accessible at a shorter λ photolysis . These results suggest that the N− H and N−C bond dissociations are connected, and these dissociations cause different photochemistry between primary/secondary amines and tertiary amines.

show abstract

Section: Experimental and Theoretical Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%