scholarly journals Dynamical signatures from competing, nonadiabatic fragmentation pathways of S-nitrosothiophenol

2020 ◽  
Vol 22 (21) ◽  
pp. 12187-12199
Author(s):  
K. Jacob Blackshaw ◽  
Marcus Marracci ◽  
Robert T. Korb ◽  
Naa-Kwarley Quartey ◽  
Annalise K. Ajmani ◽  
...  
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Excited Electronic State ◽  
Spin Orbit ◽  
Fragmentation Pathways ◽  
Uv Photolysis ◽  
Joint Experiment

A joint experiment-theory study of the UV photolysis of S-nitrosothiophenol reveals competing photodissociation pathways that produce NO in its spin–orbit ground state and thiophenoxy radical in either its ground or excited electronic state.

Molecular Modelling of Ground- and Excited-States Vibrations in Organic Conducting Devices: Hexakis(n-hexyloxy)triphenylene (HAT6) as Case Study

2010 ◽  
Vol 63 (3) ◽  
pp. 388 ◽  
Author(s):  
M. Zbiri ◽  
M. R. Johnson ◽  
L. Haverkate ◽  
F. M. Mulder ◽  
G. J. Kearley
Keyword(s):  
Excited State ◽  
Electronic State ◽  
Ground State ◽  
Density Functional ◽  
Excited Electronic State ◽  
Molecular Vibrations ◽  
Functional Theory ◽  
Model Calculations ◽  
Insight Into

In order to gain insight into fundamental aspects of organic photocell materials, we have calculated ground and excited electronic-state structures and molecular vibrations for an isolated HAT6 molecule (hexakis(n-hexyloxy)triphenylene). Excited-state calculations are carried out using time-dependent density functional theory and frequencies are evaluated analytically using coupled perturbed Kohn–Sham equations. These model calculations have been validated against new infrared and ultraviolet data on HAT6 in solution. The main allowed valence excitation, having the largest oscillator strength, is chosen for the structural and vibrational investigations. Comparison with the ground-state vibrational dynamics reveals surprisingly large spectral differences. In addition, the alkoxy tails, which are usually considered to play only a structural role, are clearly involved in the molecular vibrations and the structural distortion of the excited electronic state compared with the ground state. The tails may play a more important role in charge separation, transport and excited-state relaxation than was previously thought. In this case, chemical modification of the tails would allow vibrational and related properties of organic photocell materials to be tailored.

Relative rates of reaction of olefins with the ground and the first excited electronic states of methylene

1967 ◽  
Vol 45 (6) ◽  
pp. 665-673 ◽  
Author(s):  
S. Krzyzanowski ◽  
R. J. Cvetanović
Keyword(s):  
Electronic State ◽  
Ground State ◽  
Room Temperature ◽  
Excited Electronic State ◽  
Electronic States ◽  
Excited Electronic States

Relative rates of reaction of a number of olefins with the ground state triplet and the first excited electronic state (the lowest singlet) of methylene have been determined at room temperature. The rates depend relatively little on olefin structure. Triplet methylene is somewhat more discriminating and, in particular, reacts considerably more rapidly with 1,3-butadiene than with monoolefins.

Potential-energy curves of the CH radical molecule under spin-orbit coupling

2008 ◽  
Vol 86 (10) ◽  
pp. 1145-1151 ◽  
Author(s):  
C Song ◽  
H Han ◽  
Y Zhang ◽  
Y Yu ◽  
T Gao
Keyword(s):  
Experimental Data ◽  
Potential Energy ◽  
Electronic State ◽  
Bound States ◽  
Excited Electronic State ◽  
Orbit Coupling ◽  
Potential Energy Curves ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Ch Radical

Potential energy curves for the ground and excited electronic states of the CH radical molecule were calculated employing spin-orbit multiconfiguration quasi-degenerate perturbation theory (SO-MCQDPT). The results of our present SO-MCQDPT calculation for the CH radical molecule indicate that the ground electronic state of X 2Π splits into lower X1 2Π1/2 and higher X2 2Π3/2Ω states. The excited electronic state of a 4Σ– splits into lower a1 4Σ–1/2 and higher a24Σ–3/2, and the excited electronic state of A 2Δ splits into lower A1 2Δ3/2 and higher A2 2Δ5/2. The spin-orbit splittings for the 2S+1Λ states X 2Π, a 4Σ–, and A 2Δ are determined to be 25.963, 0.016, and 0.992 cm–1, respectively. The splittings are in good agreement with the experimental data for X 2Π and A 2Δ , and there are no experimental data for a 4Σ–. The potential-energy curves for all calculated bound states of CH are fitted to an analytical potential-energy function in the large range of R = 0.06–0.55 nm, from which accurate spectroscopic parameters are derived. It is the first time that the eight Ω states (X1 2Π1/2, X2 2Π3/2, a1 4Σ–1/2, a2 4Σ–3/2, A1 2Δ3/2, A2 2Δ5/2, B2Σ–1/2, and C2Σ+1/2) generated from the five valence 2S+1 Λ states (X 2Π , a 4Σ–, A 2Δ, B 2Σ–, and C 2Σ+) among those dissociating up to H(2Sg)+C(1Dg) have been studied theoretically. In addition, the carbon atom was taken as an example to prove the validity of the SO-MCQDPT method. The agreement between calculated and observed spin-orbit coupling is vert good. PACS Nos.: 31.15.aj, 31.15.xh, 71.70.Ej

scholarly journals SCCS−radical: Renner-Teller effect and spin-orbit coupling in the X 2Πu electronic state

2019 ◽  
Vol 84 (8) ◽  
pp. 801-817 ◽  
Author(s):  
Stanka Jerosimic ◽  
Marko Mitic ◽  
Milan Milovanovic
Keyword(s):  
Ab Initio ◽  
Electronic State ◽  
Ground State ◽  
Combined Treatment ◽  
Chem Phys ◽  
Teller Effect ◽  
Spin Orbit ◽  
Orbit Splitting ◽  
Spin Orbit Splitting ◽  
Spin Orbit Interactions

SCCS- was detected by laser-induced fluorescence spectroscopy in 2003 (M. Nakajima, Y. Yoneda, Y. Sumiyoshi, T. Nagata, Y. Endo, J. Chem. Phys. 119 (2003) 7805) and its spectrum was analyzed and the results presented together with ab initio calculations data. Symmetrical stretching vibrations were assigned in both the ground X 2?u and the first excited A 2?g electronic states, but no data about spin?orbit splitting and bending vibrational modes were given. In the present work, the vibronic levels in the ground electronic state of SCCS- were calculated by means of a model developed by Peric and coworkers for the treatment of the Renner?Teller effect in any-atomic linear species in its variational form (M. Mitic, R. Rankovic, M. Milovanovic, S. Jerosimic, M. Peric, Chem. Phys. 464 (2016) 55) using the ab initio multireference configuration interaction calculations for obtaining potential energy curves in the Born?Oppenheimer approximation. Additionally, the spin?orbit splitting in the ground state was investigated taking into account the interaction with the first excited state, and the energies obtained from combined treatment of vibronic and spin?orbit interactions in the ground state are reported. Finally, based on the present results, several assignments of unidentified bands reported by Nakajima et al. are proposed.

Variational Method for Estimating the Dipole Moment in the Second Excited State of Fluorescein Molecule from its Electronic UV Absorption Spectra

2019 ◽  
Vol 70 (10) ◽  
pp. 3538-3544
Author(s):  
Alina Costina Luca ◽  
Ana Cezarina Morosanu ◽  
Irina Macovei ◽  
Dan Gheorghe Dimitriu ◽  
Dana Ortansa Dorohoi ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Variational Method ◽  
Electronic State ◽  
Excited Electronic State ◽  
Spectral Band ◽  
Uv Absorption ◽  
Optical Parameters ◽  
Electrical Permittivity ◽  
Fluorescein Molecule

Electro-optical parameters of fluorescein molecule in the second excited electronic state and information on the interactions with solvents were obtained from a solvatochromic study. Parameters of the solvents such as the refractive index, electrical permittivity and Kamlet-Taft parameters (hydrogen bond acidity and basicity) were related with the experimentally recorded shifts of UV absorption spectral band of fluorescein dissolved in several solvents. Through a variational method, the electric dipole moment and polarizability in excited state of fluorescein molecule were estimated. The calculus requires some parameters of the fluorescein molecule in the ground electronic state, which were determined through a quantum-mechanical study.

scholarly journals First principles calculations of the structural, electronic, magnetic, and thermodynamic properties of the Nd2MgGe2 and Gd2MgGe2 intermetallic compounds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Menouer ◽  
O. Miloud Abid ◽  
A. Benzair ◽  
A. Yakoubi ◽  
H. Khachai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermodynamic Properties ◽  
Ground State ◽  
First Principles ◽  
Essential Role ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rare Earth Compounds ◽  
First Principles Calculations ◽  
Antiferromagnetic Ground State

AbstractIn recent years the intermetallic ternary RE2MgGe2 (RE = rare earth) compounds attract interest in a variety of technological areas. We therefore investigate in the present work the structural, electronic, magnetic, and thermodynamic properties of Nd2MgGe2 and Gd2MgGe2. Spin–orbit coupling is found to play an essential role in realizing the antiferromagnetic ground state observed in experiments. Both materials show metallicity and application of a Debye-Slater model demonstrates low thermal conductivity and little effects of the RE atom on the thermodynamic behavior.

Spin-orbit interval in the ground state of F-like ions

1982 ◽  
Vol 26 (4) ◽  
pp. 1984-1987 ◽  
Author(s):  
Y. -K. Kim ◽  
K. -N. Huang
Keyword(s):  
Ground State ◽  
Spin Orbit

scholarly journals The flame spectrum of carbon monoxide

1940 ◽  
Vol 176 (967) ◽  
pp. 505-521 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Electronic State ◽  
Excited Electronic State ◽  
Combustion Process ◽  
Wave Number ◽  
Band Spectrum ◽  
Liquid Form ◽  
Triangular Form ◽  
Reduced Pressure

The spectrum of the flame of carbon monoxide burning in air and in oxygen at reduced pressure has been photographed on plates of high contrast which display the band spectrum clearly above the continuous background. Greater detail has been obtained than has been recorded previously and new measurements are given. The structure of the spectrum has been studied systematically. It is shown that the bands occur in pairs with a separation of about 60 cm. -1 , this separation being due probably to the rotational structure. Various wave-number differences are found to occur frequently, and many of the strong bands are arranged in arrays using intervals of 565 and 2065 cm. -1 . The possible origin of the spectrum is discussed. The choice of emitter is limited to a polyatomic oxide of carbon, of which carbon dioxide is the most likely. The spectrum of the suboxide C 3 O 2 shows some resemblance to the flame bands, but this molecule is improbable as the emitter on other grounds. A peroxide C0 3 is also a possibility, but no evidence for the presence of this has been obtained from experiments on the slow combustion of carbon monoxide. Carbon dioxide in gaseous or liquid form is transparent through the visible and quartz ultra-violet, and the flame bands are not obtained from CO 2 in discharge tubes. Comparison with the Schumann-Runge bands of oxygen shows that it is possible that the flame bands may form part of the absorption band system of CO 2 which is known to exist below 1700 A if there is a big change in shape or size of the molecule in the two electronic states. The electronic energy levels of CO 2 are discussed. Since normal CO 2 is not built up from normal CO and oxygen, an electronic rearrangement of the CO 2 must occur after the combustion process. Mulliken has suggested that the molecule in the first excited electronic state, corresponding to absorption below 1700 A, may have a triangular form. The frequencies obtained from the flame bands are compared with the infra-red frequencies of CO 2 . The 565 interval may be identified with the transverse vibration v 2 , indicating that the excited electronic state is probably triangular in shape. The 2065 interval cannot, however, be identified with the asymmetric vibration v 3 with any certainty. If the excited electronic state of CO 2 is triangular, then molecules formed during the combustion by transitions from this level to the ground state may be “vibrationally activated”. This is probably the reason for many of the peculiarities of the combustion of carbon monoxide.

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