The Continuous Absorption Spectra of Chlorine, Bromine, Bromine Chloride, Iodine Chloride, and Iodine Bromide

1964 ◽  
Vol 68 (8) ◽  
pp. 2263-2266 ◽  
Author(s):  
Daniel J. Seery ◽  
Doyle Britton
Keyword(s):  
Absorption Spectra ◽  
Bromine Chloride ◽  
Continuous Absorption ◽  
Iodine Chloride ◽  
Iodine Bromide

The absorption spectra of irradiated diamonds after heat treatment

1956 ◽  
Vol 237 (1208) ◽  
pp. 75-89 ◽  
Keyword(s):  
Absorption Spectra ◽  
Absorption Lines ◽  
Type I ◽  
Type Ii ◽  
Large Reduction ◽  
Isothermal Heating ◽  
Interstitial Carbon ◽  
Crystal Imperfections ◽  
Continuous Absorption ◽  
Kinetics Of

The absorption spectra of eight type I and three type II a diamonds irradiated with neutrons, electrons or y-rays have been recorded at 80 and 290°K after various heat treatments in the temperature range 0 to 900°C. It is found that heating in the range 350 to 450°C causes a general reduction in the irradiation-induced absorption owing to the recombination of those interstitials and vacancies which are near neighbours. Heating type II a diamonds at 600°C causes a large reduction in the irradiation-induced lines and new lines appear. These are probably due to pairs of identical defects, and the kinetics of their formation during isothermal heating at 600°C are presented. At higher temperatures all absorption lines in type II a diamonds disappear and only continuous absorption remains. This is probably due to amorphous or graphitic regions produced by agglomeration of defects. Type I diamonds show the same kind of absorption, but in addition show an increase in strength of the natural lines and also some new absorption lines which are not removed by heating at 900°C. It is suggested that these additional processes are due to the anchoring of vacant atomic sites and interstitial carbon atoms at crystal imperfections present only in type I diamonds.

scholarly journals Transient absorption and laser gain in e-beam-excited Ar/Kr/NF3(F2 + N2) gas mixtures

2011 ◽  
Vol 29 (1) ◽  
pp. 141-152
Author(s):  
N.N. Ustinovskii ◽  
A.O. Levchenko ◽  
V.D. Zvorykin
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Transient Absorption ◽  
Optical Gain ◽  
Plasma Source ◽  
Single Shot ◽  
Optical Amplification ◽  
Excitation Rate ◽  
Broadband Absorber ◽  
Continuous Absorption

AbstractNewly developed erosion-plasma-source probe technique has been applied for virtually single shot recording of absorption/fluorescence spectra in the 190–510 nm spectral range of e-beam-excited Ar/Kr/NF3(F2 + N2) mixtures. The e-beam excitation rate of about 1 MW/cm3 is typical of large-volume rare-gas halide lasers. It is experimentally observed that, in Kr/F2 and Ar/F2 mixtures, fluorescence and absorption spectra of Rg2F species are shifted with respect to each other in the opposite direction. Continuous absorption spectrum of Ar2F excimer is reported, as far as we know, for the first time in the refereed literature. Strong overlapping between the fluorescence and absorption spectra of Ar2F is responsible for absence of lasing on Ar2F molecule. Absorption spectrum of Kr2F excimer is recorded in pure form using the mixture (Ne/Kr/F2) with no alternative broadband absorber. Minor additive of nitrogen to Ar/Kr/F2 mixture or use of NF3 instead of F2 has been found to result in broadband optical amplification centered at λ ~ 460 nm. The maximum optical gain is estimated as about 0.1 ± 0.05 m−1.

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 ).

Electrophilic ipso-Halocyclization of N-Phenyl-N-triflylpropiolamides Leading to 8-Halo-1-azaspiro[4.5]deca-3,6,9-trien-2-ones

Synthesis ◽  
2020 ◽  
Vol 52 (10) ◽  
pp. 1489-1497
Author(s):  
Gerhard Maas ◽  
Vito A. Fiore ◽  
Michael Keim ◽  
Roland Werz
Keyword(s):  
Amide Bond ◽  
Secondary Amines ◽  
Primary Amines ◽  
Iodine Chloride ◽  
Iodine Bromide

N-Phenyl-N-triflylpropiolamides react with iodine chloride or iodine bromide by an intramolecular electrophilic ipso-halocyclization/nucleophilic halide addition sequence to furnish cyclohexadiene-spiro-γ-lactams. These products can undergo cleavage of the amide bond with primary amines and of the N–Cspiro bond with secondary amines, leading to N-alkyl-2-iodo-3-phenylacrylamides and N-(4-halophenyl)-2-iodo-3-(2-triflylamino)phenylacrylamides, respectively.

Potential barrier effects beyond the 4f photoionization thresholds in Pb I

1976 ◽  
Vol 348 (1653) ◽  
pp. 235-238 ◽  
Keyword(s):  
Absorption Spectra ◽  
Potential Barrier ◽  
Central Field ◽  
Discrete Structure ◽  
Barrier Effects ◽  
Independent Particle ◽  
Continuous Absorption

New Pb I absorption spectra show discrete structure due to excitation of the 4f subshell and continuous absorption beyond the 4f thresholds. The results are compared with those previously obtained in Tl I and Hg I, and the presence of additional maxima in the Pb I spectrum is accounted for by comparison with recent independent-particle non-relativistic central field calculations.

Studies of the explosive combustion of hydrocarbons by kinetic spectroscopy - II. Comparative investigations of hydrocarbons and a study of the continuous absorption spectra

1955 ◽  
Vol 227 (1171) ◽  
pp. 423-433 ◽  
Keyword(s):  
Absorption Spectra ◽  
Thermal Equilibrium ◽  
Flash Photolysis ◽  
Total Carbon ◽  
Carbon Particles ◽  
Continuous Absorption ◽  
Flash Spectroscopy ◽  
Characteristic Maximum ◽  
The Continuum ◽  
Carbon Molecule

The absorption spectra of explosions of ethylene, ethane and methane with oxygen, initiated by the flash photolysis of nitrogen dioxide, have been studied kinetically by flash spectroscopy and the results are compared with those already given for acetylene. The occurrence of the diatomic radical spectra is qualitatively similar in the four hydrocarbons, but there are important quantitative differences in the stoicheiometry of the mixtures which give equivalent spectroscopic results. The continuous spectra and the spectrum of C 3 have been studied in more detail. The continuum which is present after the explosion is shown to be due to absorption by carbon particles. A second intense continuous spectrum, which has a characteristic maximum at 3900 Å and whose occurrence follows closely that of the radicals C 2 and C 3 , is attributed to a carbon molecule which is in approximate thermal equilibrium and whose concentration must form a considerable fraction of the total carbon present in the vapour during the explosion.

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