THE ULTRAVIOLET ABSORPTION SPECTRA OF NITROGUANIDINE DERIVATIVES

1953 ◽  
Vol 31 (1) ◽  
pp. 42-47 ◽  
Author(s):  
A. F. McKay ◽  
C. Sandorfy
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Linear Structure ◽  
Addition Product ◽  
Ultraviolet Absorption ◽  
Ethanol Addition ◽  
Nitroguanidine Derivatives ◽  
Amine Addition

The ultraviolet absorption spectra of the ammonia and amine addition products of 1-nitro-2-nitramino-2-imidazoline verify the linear structure A for these compounds. Also the ethanol addition product is considered on the basis of [Formula: see text]its absorption spectrum to be N-β-nitraminoethyl-N-nitro-o-ethylisourea. The relative effects of the nitramino and nitroguanidine chromophores on the absorption spectra of several nitroguanidine derivatives are discussed.

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 ULTRAVIOLET ABSORPTION SPECTRA OF ALIPHATIC NITRAMINES, NITROSAMINES, AND NITRATES

1949 ◽  
Vol 27b (11) ◽  
pp. 828-860 ◽  
Author(s):  
R. Norman Jones ◽  
G. Denis Thorn
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ultraviolet Spectrum ◽  
Ultraviolet Absorption ◽  
Absorption Bands ◽  
Structure Formula ◽  
New Compounds

The ultraviolet absorption bands associated with the following groups have been investigated in a variety of compounds of known structure:[Formula: see text]The groups may be characterized by the ultraviolet spectrum, and the number of each type of group present in a given compound may be estimated from an analysis of the shape and intensity of the absorption spectrum. These correlations have been applied to the elucidation of the structure of new compounds isolated in the course of the investigation of the chemistry of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX).

ULTRAVIOLET ABSORPTION SPECTRA OF HCN AND DCN: I. THE α—X AND β—X SYSTEMS

1957 ◽  
Vol 35 (8) ◽  
pp. 842-879 ◽  
Author(s):  
G. Herzberg ◽  
K. K. Innes
Keyword(s):  
Fine Structure ◽  
Absorption Spectra ◽  
Excited States ◽  
Linear Structure ◽  
Ultraviolet Absorption ◽  
Geometrical Parameters ◽  
Rotational Analysis ◽  
Long Wavelength ◽  
Non Linear ◽  
The Asymmetry

The ultraviolet absorption spectra of HCN and DCN have been investigated below 2000 Å. Four band systems have been found of which two, α—X and β—X, are described and analyzed in the present paper. At the long wavelength end the α—X system in both HCN and DCN consists of simple progressions of sharp bands whose fine structure has been measured. At shorter wavelengths diffuseness (predissociation) sets in gradually but at somewhat different energies in HCN and DCN. Both the vibrational and rotational analyses lead independently and unambiguously to the conclusion that in the upper state, α, unlike in the ground state, the molecule is non-linear. The geometrical parameters obtained from the rotational fine structure are r0(CH) = 1.140 Å, r0(CN) = 1.297 Å, and [Formula: see text]H—C—N = 125.0°. Two vibrational frequencies in the α state are established: for HCN, ν1 = 1506, ν2 = 949; for DCN, ν1 = 1506, ν2 = 735 cm−1. The CH stretching frequency has not been found.The β—X system has been clearly observed only for DCN. In HCN it is apparently so strongly predissociated that its presence among the diffuse α—X bands is difficult to establish. In the β state, as in the α state, the molecule is bent. The somewhat fragmentary rotational analysis leads to r0(CN) = 1.334 Å and [Formula: see text]D—C—N = 114.5° when r0(CD) = 1.140 Å is assumed. Only one vibrational frequency, ν2 = 731 cm−1, has been established in the β state of DCN. The vibrational quantum number v2 is uncertain since no isotope effect is available to establish the position of the 0–0 band.In the rotational analysis, particularly of the α—X system, the effects of the asymmetry of the molecule in the upper state are clearly demonstrated by the doubling of the levels with K = 1 and K = 2 and the large contributions of the asymmetry to the terms in J2(J + 1)2. From the sign of the K-type doubling for K = 1 it follows unambiguously that both the α and the β state belong to the species A″, i.e. the electronic eigenfunctions are antisymmetric with respect to the plane of the molecule. It appears probable that both transitions α—X and β—X correspond to forbidden transitions (1Δ—1Σ+ and 1Σ−—1Σ+) of the linear case. The non-linear structure of the excited states is briefly discussed in terms of electron configurations.A number of interesting features of the predissociation in the α state are pointed out. It is shown that the dissociation products are in all probability H + CN(2Π).

scholarly journals THE STRUCTURE OF THE ULTRAVIOLET ABSORPTION SPECTRA OF CERTAIN PROTEINS AND AMINO ACIDS

1936 ◽  
Vol 19 (5) ◽  
pp. 739-752 ◽  
Author(s):  
Calvin B. Coulter ◽  
Florence M. Stone ◽  
Elvin A. Kabat
Keyword(s):  
Amino Acids ◽  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Relative Intensity ◽  
Ultraviolet Absorption ◽  
Absorption Curve ◽  
Type I ◽  
Narrow Bands ◽  
Pneumococcus Type

1. The absorption spectra of a number of proteins in the region 2500 to 3000 A. have been found to comprise from six to nine narrow bands. In consequence of variation in the relative intensity of these bands from protein to protein, the absorption curve has a characteristic configuration for each protein. 2. These bands correspond closely in position with the narrow bands which appear in the absorption spectra of tryptophan, tyrosin, and phenylalanine. Tryptophan and tyrosin each present three bands, phenylalanine shows nine. 3. The bands in the proteins are accordingly attributed to these amino acids. In the proteins the bands are displaced from the positions which they occupy in the uncombined amino acids, in most instances, by 10 to 35 A. toward longer wavelengths. 4. The absorption spectrum of Pneumococcus Type I antibody resembles that of normal pseudoglobulin but shows characteristic differences.

Near Ultraviolet Absorption Spectra of cis and trans Acrolein and Acrolein-d1

1973 ◽  
Vol 51 (11) ◽  
pp. 1170-1175 ◽  
Author(s):  
G. A. Osborne ◽  
D. A. Ramsay
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Vibrational Structure ◽  
Ultraviolet Absorption ◽  
Additional Information ◽  
Near Ultraviolet ◽  
New Information ◽  
Path Lengths ◽  
Cis And Trans

The absorption spectrum of acrolein-d1 (CH2=CH∙CDO) has been studied in the region 3900 to 4400 Å with path lengths and pressures up to 10 m atm and temperatures from 25 to 160 °C. This study provides additional information for the interpretation of the vibrational structure observed in the 3A″–1A′ (trans), 1A″–1A′ (cis), and 3A″–1A′ (cis) systems of acrolein, in addition to new information for acrolein-d1. Most of the features in these spectra are now assigned.

Applications of Ultraviolet Spectrography a Study of the Transformations of Tetramethylthiuram Disulfide When It Functions as a Direct Vulcanizing Agent

1944 ◽  
Vol 17 (4) ◽  
pp. 941-942 ◽  
Author(s):  
Charles Dufraisse ◽  
André Jarrijon
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Special Technique ◽  
Ultraviolet Region ◽  
Tetramethylthiuram Disulfide ◽  
Important Method ◽  
Characteristic Absorption ◽  
Definite Form ◽  
Inorganic And Organic

Abstract In addition to sulfur, which is the most common vulcanizing agent, rubber mixtures usually contain various kinds of accessory ingredients, both inorganic and organic. Among the organic ingredients, some, notably accelerators and antioxidants, are present in relatively small proportions, and these are susceptible to transformation during vulcanization. However, only in rare cases has it been possible to isolate in definite form the products of these transformations, and consequently it is difficult to interpret the part played by these substances during vulcanization. Since, with few exceptions, each accelerator and each antioxidant has its own characteristic absorption spectrum in the ultraviolet region, spectrography constitutes in general an important method for following the behavior of accelerators and antioxidants. This method has been demonstrated by Dufraisse and Houpillart, who have developed a special technique for obtaining ultraviolet absorption spectra and examining them, frequently with interesting conclusions to be drawn from such analyses.

THE STRUCTURES OF NITROGUANIDINE AND ITS DERIVATIVES

1951 ◽  
Vol 29 (9) ◽  
pp. 746-758 ◽  
Author(s):  
A. F. McKay ◽  
J. P. Picard ◽  
P. E. Brunet
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Derivatives Of ◽  
Resonance Hybrid

The ultraviolet absorption spectra of a number of derivatives of nitroguanidine were determined. An analysis of the effects of substituents on the absorption spectrum of nitroguanidine has led to the conclusion that it exists as a resonance hybrid of several structures including (a) and (b).[Formula: see text]The bearing of these structures on the nomenclature of nitroguanidine and its derivatives is discussed. Also the structures of some of the derivatives of nitroguanidine have been interpreted from their absorption spectra.

FAR ULTRAVIOLET ABSORPTION SPECTRA OF N3AND N2+GENERATED BY ELECTRONS IMPACTING GASEOUS N2

2013 ◽  
Vol 779 (1) ◽  
pp. 40 ◽  
Author(s):  
Yu-Jong Wu ◽  
Hui-Fen Chen ◽  
Shiang-Jiun Chuang ◽  
Tzu-Ping Huang
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Far Ultraviolet
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