The Spectroscopy of Formaldehyde and Thioformaldehyde

Clouthier, Dennis J.; Ramsay, D. A.

doi:10.1146/annurev.pc.34.100183.000335

Cited by 482 publications

(330 citation statements)

References 0 publications

Supporting

Mentioning

298

Contrasting

Unclassified

Order By: Relevance

“…The first excited electronic state (S 1 ) of H 2 CS has nπ * character in the Franck-Condon region and its 0-0 transition energy has been experimentally determined at 2.033 eV. 39 Two triplet states lie close to S 1 : T 1 (nπ * ) and T 2 (ππ * ). When the excited-state dynamics of H 2 CS is initiated in S 1 , we therefore expect to observe a direct application of the El-Sayed rules 40 -S 1 (nπ * ) should be more strongly coupled to T 2 (ππ * ) via SOC than to T 1 (nπ * ) as a result of the change in orbital type.…”

Section: Test Applicationsmentioning

confidence: 99%

Communication: GAIMS—Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes

Curchod

Rauer

Marquetand

et al. 2016

The Journal of Chemical Physics

101

103

View full text Add to dashboard Cite

A new approach to molecular dynamics with non-adiabatic and spin-orbit effects with applications to QM/MM simulations of thiophene and selenophene The Journal of Chemical Physics 146, 114101 (2017); 10.1063/1.4978289 THE JOURNAL OF CHEMICAL PHYSICS 144, 101102 (2016) Communication: GAIMS-Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes Full multiple spawning is a formally exact method to describe the excited-state dynamics of molecular systems beyond the Born-Oppenheimer approximation. However, it has been limited until now to the description of radiationless transitions taking place between electronic states with the same spin multiplicity. This Communication presents a generalization of the full and ab initio multiple spawning methods to both internal conversion (mediated by nonadiabatic coupling terms) and intersystem crossing events (triggered by spin-orbit coupling matrix elements) based on a spin-diabatic representation. The results of two numerical applications, a model system and the deactivation of thioformaldehyde, validate the presented formalism and its implementation. C 2016 AIP Publishing LLC. [http://dx

show abstract

Section: Test Applicationsmentioning

confidence: 99%

Communication: GAIMS—Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes

Curchod

Rauer

Marquetand

et al. 2016

The Journal of Chemical Physics

101

103

View full text Add to dashboard Cite

show abstract

“…where the product for the planar CH 2 O is over the six vibrational normal modes with frequencies ν 1 , ..., ν 6 [20,21]. The population of the vibrational ground state reduces to 1/Z vib and is plotted as a function of temperature in Figure 5 (a).…”

Section: Lif Correctionsmentioning

confidence: 99%

“…where J is the total angular momentum quantum number, K its component along the molecule's symmetry axis, A > B > C are the rotational constants and B = 1/2 (B+C) [22,20]. Due to the dense structure of the formaldehyde spectrum and the relatively broad excitation linewidth of the multimode laser, several transitions contribute [23].…”

Section: Lif Correctionsmentioning

confidence: 99%

“…Comparison with the reference spectrum, which was taken in the vapor phase over a formalin solution (dotted line), provides confirmation of formaldehyde detection. The vibrational bands observed are attributed to transitions in the CO stretch and the out-of-plane bending vibrations, designated 2 0 n 4 1 m (n, m = 0, 1, 2, ...) with respect to the notation by Clouthier and Ramsay [20]. At the same time a changing broadband background is noticeable, the origin of which could not be unambiguously identified but might be attributed to fluorescence of polyaromatic hydrocarbons (PAH).…”

Section: Reactor Modelingmentioning

confidence: 99%

See 1 more Smart Citation

Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Schwarz

Geske

Goldsmith³

et al. 2014

Combustion and Flame

View full text Add to dashboard Cite

A versatile flow-reactor design is presented that permits multi-species profile measurements under industrially relevant temperatures and pressures. The reactor combines a capillary sampling technique with a novel fiber-optic Laser-Induced Fluorescence (LIF) method. The gas sampling provides quantitative analysis of stable species by means of gas chromatography (i.e. CH 4 , O 2 , CO, CO 2 , H 2 O, H 2 , C 2 H 6 , C 2 H 4 ), and the fiber-optic probe enables in situ detection of transient LIF-active species, demonstrated here for CH 2 O. A thorough analysis of the LIF correction terms for the temperature-dependent Boltzmann fraction and collisional quenching are presented. The laminar flow reactor is modeled by solving the two-dimensional Navier-Stokes equations in conjunction with a detailed kinetic mechanism. Experimental and simulated profiles are compared. The experimental profiles provide much needed data for the continued validation of the kinetic mechanism with respect to C 1 and C 2 chemistry; additionally, the results provide mechanistic insight into the reaction network of fuel-rich gas-phase methane oxidation, thus allowing optimization of the industrial process.

show abstract

“…Use of formaldehyde is motivated by our research on cold polar molecules [4,5] where formaldehyde has several advantages: a large linear Stark shift, a high vapor pressure and a relatively accessible electronic transition in the near ultraviolet [6]. Formaldehyde is one of the best studied polyatomic molecules [7,8] and is still topic of active research [9]. Nevertheless, Doppler-free spectroscopy of formaldehyde has not been FIG.…”

Section: Introductionmentioning

confidence: 99%

Doppler-free spectroscopy of weak transitions: An analytical model applied to formaldehyde

et al. 2007

View full text Add to dashboard Cite

Experimental observation of Doppler-free signals for weak transitions can be greatly facilitated by an estimate for their expected amplitudes. We derive an analytical model which allows the Doppler-free amplitude to be estimated for small Doppler-free signals. Application of this model to formaldehyde allows the amplitude of experimentally observed Doppler-free signals to be reproduced to within the experimental error.

show abstract

The Spectroscopy of Formaldehyde and Thioformaldehyde

Cited by 482 publications

References 0 publications

Communication: GAIMS—Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes

Communication: GAIMS—Generalized Ab Initio Multiple Spawning for both internal conversion and intersystem crossing processes

Fuel-rich methane oxidation in a high-pressure flow reactor studied by optical-fiber laser-induced fluorescence, multi-species sampling profile measurements and detailed kinetic simulations

Doppler-free spectroscopy of weak transitions: An analytical model applied to formaldehyde

Contact Info

Product

Resources

About