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.

scholarly journals Unveiling the role of upper excited electronic states in the photochemistry and laser performance of anti-B18H22

2020 ◽  
Vol 8 (37) ◽  
pp. 12806-12818 ◽  
Author(s):  
Luis Cerdán ◽  
Antonio Francés-Monerris ◽  
Daniel Roca-Sanjuán ◽  
Jonathan Bould ◽  
Jiří Dolanský ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Electronic State ◽  
Theoretical Approach ◽  
Excited Electronic State ◽  
Electronic States ◽  
Excited Electronic States ◽  
Laser Performance ◽  
Highly Efficient

Using the first laser borane, anti-B18H22, as a case study, our combined experimental and theoretical approach unravels the photophyscial and photochemical molecular dynamics of a highly efficient luminophore in an excited electronic state.

THE ABSORPTION SPECTRUM OF CF2

1967 ◽  
Vol 45 (7) ◽  
pp. 2355-2374 ◽  
Author(s):  
C. Weldon Mathews
Keyword(s):  
Absorption Spectrum ◽  
Electronic State ◽  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Vibrational Structure ◽  
Rotational Structure ◽  
Transition Moment ◽  
High Dispersion ◽  
Parallel Type

The absorption spectrum of CF2 in the 2 500 Å region has been photographed at high dispersion, and the rotational structure of a number of bands has been analyzed. The analysis of the well-resolved subbands establishes that these are perpendicular- rather than parallel-type bands, as previously assigned. Further analysis shows that the upper and lower electronic states are of 1B1 and 1A1symmetries respectively, corresponding to a transition moment that is perpendicular to the plane of the molecule. In the upper electronic state, r0(CF) = 1.32 Å and [Formula: see text], while in the ground state, r0(CF) = 1.300 Å and [Formula: see text]. An investigation of the vibrational structure of the band system has shown that the vibrational numbering in ν2′ must be increased by one unit from earlier assignments, thus placing the 000–000 band near 2 687 Å (37 220 cm−1). A search between 1 300 and 8 500 Å showed two new band systems near 1 350 and 1 500 Å which have been assigned tentatively to the CF2 molecule.

scholarly journals Ab Initio Study of Ground-state CS Photodissociation via Highly Excited Electronic States

2019 ◽  
Vol 882 (2) ◽  
pp. 86 ◽  
Author(s):  
Zhongxing Xu ◽  
Nan Luo ◽  
S. R. Federman ◽  
William M. Jackson ◽  
Cheuk-Yiu Ng ◽  
...  
Keyword(s):  
Ab Initio ◽  
Ground State ◽  
Electronic States ◽  
Ab Initio Study ◽  
Excited Electronic States

Controlled intramolecular H-transfer in malonaldehyde in the electronic ground state mediated through the conical intersection of 1nπ* and 1ππ* excited electronic states

2019 ◽  
Vol 21 (36) ◽  
pp. 20018-20030 ◽  
Author(s):  
K. R. Nandipati ◽  
Arun Kumar Kanakati ◽  
H. Singh ◽  
S. Mahapatra
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Laser Pulses ◽  
Electronic Ground State ◽  
Conical Intersection ◽  
Uv Laser ◽  
Excited Electronic States ◽  
Electronic Ground

We report photo-isomerization of malonaldehyde in its electronic ground state (S0), mediated by coupled 1nπ*(S1)–1ππ*(S2) excited electronic states, accomplished with the aid of optimally designed ultraviolet (UV)-laser pulses.

The Thermal Emission of Iodine

1974 ◽  
Vol 52 (19) ◽  
pp. 1862-1871
Author(s):  
J. David Brown ◽  
George Burns
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Temperature Dependence ◽  
Electronic State ◽  
Reasonable Agreement ◽  
Thermal Emission ◽  
Electronic States ◽  
Excited Electronic States ◽  
Calculated Temperature ◽  
Calculated Temperature Dependence

The temperature dependence of emission from iodine, heated in a shock wave to 1000 K–2000 K, has been measured at 4550, 5550, 6950, 7550, and 7820 Å. Preliminary measurements of the emission at 6380 Å were also made. The temperature dependence of the emission was calculated at these wavelengths for transitions to the ground electronic state X(1Σg+) of iodine from the excited electronic states, A(3Π1u), (1Π1u), and [Formula: see text]. The calculated results are in a reasonable agreement with experimental data. For the banded emission due to the B → X transition, a theory of the temperature dependence of emission was developed. At 6950, 7550, and 7820 Å, the results of this theory agree with the experimental data thus identifying the B → X transition as the source of emission at these wavelengths. The temperature dependence of emission at 4550 Å is consistent with calculated temperature dependence for either (1Π1u) → X or [Formula: see text] transitions. The temperature dependence of the emission at 5550 Å is consistent with calculated temperature dependence for the above two transitions, as well as for the A(3Π1u) → X transition.

The excited electronic states of the NO+ ion

1968 ◽  
Vol 46 (15) ◽  
pp. 1691-1695 ◽  
Author(s):  
K. P. Huber
Keyword(s):  
Electronic State ◽  
Photoelectron Spectrum ◽  
Electronic States ◽  
Corresponding States ◽  
Rydberg Series ◽  
Excited Electronic States ◽  
Absorption Bands ◽  
Close Analogy ◽  
New Interpretation

The photoelectron spectrum of NO (Turner and May 1966) is given a new interpretation in terms of electronic states of NO+ belonging to configurations … (5σ)2(1π)32π and … 5σ(1π)42π. The close analogy with corresponding states of N2 and CO is pointed out. The long-known β Rydberg series of absorption bands of NO is shown to converge towards … 5σ(1π)42π, 3Π, but no evidence can be found for the existence of an electronic state of NO+ at the limit of the α series. The previously assumed Rydberg character of this series appears to be erroneous.

The absorption spectrum of liquid bromine

1937 ◽  
Vol 162 (910) ◽  
pp. 414-419 ◽  
Author(s):  
D. Porret ◽  
Frederick George Donnan
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Wave Length ◽  
Electronic States ◽  
Excited Electronic States ◽  
Long Wave ◽  
Liquid Bromine ◽  
Continuous Absorption ◽  
The Continuum

The continuous absorption spectra of gaseous bromine (Peskow 1917; Ribaud 1919; Gray and Style 1929; Acton, Aikin and Bayliss 1936) and of dissolved bromine (Bovis 1929; Gillam and Morton 1929) have been studied many times. They present a wide continuum (from about 30, 000 to 17, 000 cm. -1 .) with a maximum at 24, 000 cm. -1 . For the gas the continuum is preceded by two band systems on the long wave-length side. These systems converge at 19, 585 and 15, 896 cm. -1 . respectively. Acton, Aikin and Bayliss (1936) have shown that the continuum is not simple, and Mulliken (1936) and Darbyshire (1937) have pointed out that there are three overlapping continua corresponding to transitions from the ground state to three different excited electronic states. There are 3 II 0 + ← 1 Σ g , 3 II 1 ← 1 Σ g and 1 II ← 1 Σ g . The absorption spectrum of liquid bromine has been studied by Bovis (1929) form 18, 525 to 31, 750c cm. -1 . and by Camichel (1893) for two frequencies only (16, 978 and 18, 691 cm. -1 ).

Photooxidation and Decarboxylation of Tyrosine Studied by E.P.R. and C.I.D.N.P. Techniques

1972 ◽  
Vol 50 (23) ◽  
pp. 3849-3856 ◽  
Author(s):  
Micha Tomkiewicz ◽  
Robert D. McAlpine ◽  
Michael Cocivera
Keyword(s):  
Spin Polarization ◽  
Nuclear Spin ◽  
Room Temperature ◽  
Electronic States ◽  
Tyrosyl Radical ◽  
Excited Electronic States ◽  
Nuclear Spin Polarization ◽  
Full Spectrum ◽  
The One ◽  
Text Formation

The photooxidation of deoxygenated solutions of tyrosine in water at pH 8.5–12.6 has been studied at room temperature using e.p.r. spectroscopy. By means of e.p.r., four radicals were detected during irradiation with the full spectrum of a Hg–Xe arc lamp. These were identified as the tyrosyl radical, [Formula: see text] and two radicals derived from dopa. A tentative mechanism suggested for [Formula: see text] formation involves the reaction of tyrosine with the hydrated electron, which has been ejected from another tyrosine molecule in one of its excited electronic states. A mechanism similar to the one proposed for the photooxidation of phenol has been suggested for the formation of the radicals derived from dopa. Support for this mechanism is provided by the observation of proton nuclear spin polarization during irradiation.

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