THE ABSORPTION SPECTRUM OF CNC

1966 ◽  
Vol 44 (2) ◽  
pp. 353-372 ◽  
Author(s):  
A. J. Merer ◽  
D. N. Travis
Keyword(s):  
Absorption Spectrum ◽  
Bond Length ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic States ◽  
Electronic Transitions ◽  
Ultraviolet Absorption Spectrum ◽  
Rotational Analysis ◽  
Bending Vibrations ◽  
Show Evidence

The ultraviolet absorption spectrum of the free CNC radical has been discovered in the flash photolysis of diazoacetonitrile, HC(CN)N2. The identity of the radical has been proved from isotopic evidence, using 15N and 13C, together with rotational analysis of the bands. Rotational analyses have shown that the bands of CNC must be assigned to two electronic transitions, A2Δu–X 2Πg, and [Formula: see text]. The sequence bands in the bending vibrations, which are observed in both electronic transitions, show evidence of Renner–Teller interaction in both the degenerate electronic states: this interaction is extremely large in the X2Πg state. The principal constants (in cm−1) of the observed states of CNC are as follows:[Formula: see text]The C—N bond length in the ground state of CNC is found to be 1.245 Å.CNC is isomeric with CCN, whose spectrum has been reported previously; some interesting comparisons are made between the spectra of these two molecules.

The ultraviolet absorption spectrum of the F 2 CN radical

1967 ◽  
Vol 300 (1462) ◽  
pp. 405-414 ◽  
Keyword(s):  
Molecular Structure ◽  
Absorption Spectrum ◽  
Ground State ◽  
Flash Photolysis ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Rotational Analysis ◽  
Absorption Bands ◽  
New System

A new system of absorption bands near 3600 Å has been observed during the flash photolysis of CF 3 NCF 2 and is ascribed to the free F 2 CN radical. The rotational analysis of the 0–0 band leads to the ground state molecular structure r CF = 1.310 Å (assumed), r CN = 1.265 ± 0.02 Å, FCF angle = 113.5 + 1°. The bands are shown to be type A bands arising from the transition 2 A 1 ← 2 B 2 , and the spectrum is compared with those of the iso-electronic molecules NO 3 and F 2 BO.

THE ABSORPTION SPECTRUM OF BO2

1961 ◽  
Vol 39 (12) ◽  
pp. 1738-1768 ◽  
Author(s):  
J. W. C. Johns
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Detailed Analysis ◽  
Ground State ◽  
Flash Photolysis ◽  
Electronic Transitions ◽  
Molecular Constants ◽  
Boron Trichloride ◽  
Symmetric Molecule ◽  
First Excited State

The boron flame bands have been observed in absorption during the flash photolysis of mixtures of boron trichloride and oxygen. Detailed analysis of the spectrum has shown that the bands arise from two electronic transitions in the linear symmetric molecule BO2, [Formula: see text] and A2Πu−X2Πg. The main molecular constants, in cm−1 except for r0, are summarized below:[Formula: see text]Both 2Π states show the Renner effect. In the ground state the Renner parameter, εω2, was found to be −92.2, whereas in the first excited state it is much smaller, −13.1 cm−1.

scholarly journals The Near-ultraviolet Absorption Spectrum of Diimide Vapor

1974 ◽  
Vol 52 (6) ◽  
pp. 1006-1012 ◽  
Author(s):  
R. A. Back ◽  
C. Willis ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Bond Length ◽  
Gas Phase ◽  
Absorption Spectra ◽  
Ground State ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Near Ultraviolet ◽  
Bending Mode ◽  
Franck Condon

Absorption spectra of N2H2 and N2D2 in the gas phase have been obtained in the region 3000–4300 Å, consisting of about 30 diffuse bands for each compound. Long progressions in the spectra are attributed to excitation of the H—N=N bending mode, v2′, in the upper state, with much shorter progressions arising from the N=N stretching mode, v3′; values of v2′ = 1215 and 910 cm−1 and v3′ = 1550 and 1440 cm−1 were estimated for N2H2 and N2D2 respectively.The spectra are attributed to the 1Bg ← 1Ag(π* ← n+) transition of trans diimide, probably made allowed by vibronic interaction. From Franck–Condon calculations the H—N=N angle in the upper state was estimated to be 132 ± 2°, an increase of 25° from the ground-state value; the increase in the N=N bond length was estimated to be about 0.05 Å.

THE ABSORPTION SPECTRUM OF SH AND SD IN THE VACUUM ULTRAVIOLET

1966 ◽  
Vol 44 (10) ◽  
pp. 2447-2459 ◽  
Author(s):  
B. A. Morrow
Keyword(s):  
Absorption Spectrum ◽  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Vacuum Ultraviolet ◽  
Flash Photolysis ◽  
Electronic States ◽  
Rydberg Series ◽  
A Value ◽  
Vibrational Constants

The absorption spectrum of SH in the vacuum ultraviolet has been obtained by the flash photolysis of hydrogen sulfide. Transitions from the 2Π ground state to seven excited states have been observed and four of these fit reasonably well into a Rydberg series. From an extrapolation to the convergence limit of this series, a value of 10.40 ± 0.03 eV for the ionization potential of SH has been derived. Values for the rotational constants of these new electronic states have been determined; corresponding data for SD have also been obtained. The (1–0) transition of the system near 1 670 Å (B2Σ–X2Π) was observed, and, with the aid of isotope relations, vibrational constants of the B state have been derived. An estimate of the dissociation energy of SH in this excited state is D0′ = 24 190 ± 1 000 cm−1.

ROTATIONAL ANALYSIS OF THE β BANDS OF PHOSPHORUS MONOXIDE

1959 ◽  
Vol 37 (2) ◽  
pp. 136-143 ◽  
Author(s):  
Nand Lal Singh
Keyword(s):  
Ground State ◽  
Band System ◽  
Electronic States ◽  
Rotational Analysis ◽  
Rotational Constants ◽  
Fine Structures ◽  
Π State

The fine structures of three of the β bands of PO which occur near 3200 Å have been analyzed. The analysis shows that the upper state of this band system is a 2Σ and not a 2Π state as previously believed. The rotational constants of both electronic states have been determined and it is found that the ground state constants, previously determined from the γ bands, are incorrect.

The electronic spectra of phenyl radicals

1965 ◽  
Vol 287 (1411) ◽  
pp. 457-470 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Electronic Absorption Spectrum ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Spectra ◽  
Flash Photolysis ◽  
Visible Region ◽  
Electronic Configuration ◽  
Vibrational Structure ◽  
Fundamental Frequencies

An electronic absorption spectrum, attributed to phenyl, has been observed in the visible region with origin at 18 908 cm -1 after flash photolysis of benzene and halogenobenzenes. Similar spectra of fluoro, chloro and bromo phenyl are observed after flash photolysis of disubstituted benzenes. The vibrational structure of the phenyl spectrum has been analysed in terms of two fundamental frequencies at 571 and 896 cm -1 which correspond to the e 2 g and a 1 g frequencies of the B 2 u state of benzene. The ground state of phenyl has a π 6 n electronic configuration and the observed transition is interpreted as 2 A 1 → 2 B 1 resulting from a π → n excitation.

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.

Bonding and electronic states of boron in silicon nanowires characterized by an infrared synchrotron radiation beam

Nanoscale ◽  
2015 ◽  
Vol 7 (16) ◽  
pp. 7246-7251 ◽  
Author(s):  
N. Fukata ◽  
W. Jevasuwan ◽  
Y. Ikemoto ◽  
T. Moriwaki
Keyword(s):  
Synchrotron Radiation ◽  
Excited States ◽  
Silicon Nanowires ◽  
Ground State ◽  
Electronic States ◽  
Electronic Transitions ◽  
Synchrotron Radiation Beam ◽  
Radiation Beam ◽  
Acceptor Atom ◽  
Ft Ir

The first report of B local vibrational peaks and electronic transitions of a bound hole from the ground state of a B acceptor atom to excited states by means of micro-FT-IR measurements using an IR-SR beam.

The analysis of a 2 A 1 - 2 B 1 electronic band system of the AsH 2 and AsD 2 radicals

1968 ◽  
Vol 305 (1481) ◽  
pp. 271-290 ◽  
Keyword(s):  
Excited State ◽  
Ground State ◽  
Flash Photolysis ◽  
Band System ◽  
Valence Angle ◽  
Electronic Transitions ◽  
Doublet State ◽  
Electronic Band ◽  
Asymmetric Rotor ◽  
Asymmetric Top

Two new band systems have been observed in absorption following flash photolysis of AsH 3 and AsD 3 , and are assigned to 2 A 1 - 2 B 1 electronic transitions of AsH 2 and AsD 2 . The origins of both systems are at 19905 cm -1 . The bands have the complex rotational structure associated with an asymmetric rotor. Rotational analyses have been carried out for three bands of the AsH 2 spectrum, leading to the following molecular parameters: ground state, r" 0 = 1.518 Å valence angle = 90° 44'; excited state, r' 0 = 1.48 Å, valence angle = 123° 0'. The parameters associated with rotation about the a inertial axis increase rapidly with increase in v' 2 . The spectrum shows doublet splittings of up to 41 cm -1 , and the excited state furnishes the first example of a doublet state of an asymmetric top molecule which shows substantial departures from Hund’s case ( b ).

The A2Πi–X2Πi absorption spectrum of BrO

1981 ◽  
Vol 59 (12) ◽  
pp. 1908-1916 ◽  
Author(s):  
M. Barnett ◽  
E. A. Cohen ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Flash Photolysis ◽  
Absorption Bands ◽  
Long Wavelength ◽  
Numbering Scheme ◽  
Ozonized Oxygen ◽  
Good Agreement

Absorption spectra of isotopically enriched 81Br16O and of normal BrO have been obtained by the flash photolysis of mixtures of bromine and ozonized oxygen. Rotational analyses are given for the 7–0, 12–0, 18–0, 19–0, 20–0, 21–0, 7–1, and 20–1 A2Π3/2–X2Π3/2 sub-bands of 81Br16O. The value for [Formula: see text] is found to be 722.1 ± 1.1 cm−1 in good agreement with the value calculated from microwave constants. Several additional bands have been found at the long wavelength end of the spectrum, necessitating a revision of the vibrational numbering scheme for both the emission and absorption bands. "Hot" bands up to ν″ = 6 have been observed in the absorption spectrum for the 2Π3/2 component of the ground state but no bands have yet been identified from the 2Π1/2 component.

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