Infra-red and Ultra-violet Absorption Spectra of Proteins in the Solid State

Nature ◽  
1954 ◽  
Vol 174 (4442) ◽  
pp. 1144-1145 ◽  
Author(s):  
ELTON S. COOK ◽  
CORNELIUS W. KREKE ◽  
EDWARD B. BARNES ◽  
WERNER MOTZEL
Keyword(s):  
Solid State ◽  
Absorption Spectra ◽  
Ultra Violet ◽  
Infra Red

scholarly journals The absorption spectra of some polyatomic molecules containing methyl and ethyl radicals

1935 ◽  
Vol 150 (871) ◽  
pp. 603-614 ◽  
Keyword(s):  
Absorption Spectra ◽  
Excited States ◽  
Chemical Change ◽  
Ultra Violet ◽  
Polyatomic Molecules ◽  
Point Of View ◽  
Careful Examination ◽  
Discrete Band ◽  
Infra Red ◽  
Ethyl Radicals

Although measurements on the ultra-violet absorption spectra of polyatomic molecules have rapidly multiplied in recent years, probably in no case has the structure of the entire spectrum been satisfactorily and completely interpreted. From the chemical point of view, investi­gations have been mainly directed to the study of “predissociation” processes and their correlation with the primary processes of photo­ chemical change, whilst in addition some knowledge has been gained in regard to the products of photodissociation and energies of linkage. A more careful examination of the matter has now shown that the inferences to be drawn from predissociation phenomena must be made with care, and in many cases additional measurements—for example of fluorescence or of quantum efficiencies—have to be made before the interpretations become unambiguous. From the physical standpoint, only a few band systems have been analysed in detail ( e . g ., ClO 2 , Urey and Johnston*; SO 2 , Watson and Parker,) and even in these the interpretations given may not be accurate. One aspect of the matter which has not yet received much attention, is the nature and type of the vibrations excited in polyatomic molecules. This may prove to be of considerable importance in connection with chemical kinetics. The chief difficulty in the analysis of the spectra of polyatomic mole­cules usually arises from their complexity, whilst the frequent occurrence of purely continuous spectra which may or may not overlap band systems often makes it impossible to derive much knowledge of the molecular excited states. In such cases as the latter, it may be that further in the ultra-violet, i . e ., in the Schumann region, discrete band systems may lead to knowledge of higher electronic states, but this region has so far been little explored. Herzberg and Teller* have recently attempted to con­struct selection rules for electronic and vibrational transitions in poly­atomic molecules, but even when such rules as these are applied and when the infra-red and Raman frequencies are well known, the analysis of most band systems still remains very difficult.

scholarly journals Studies of co-ordination.—Part II. absorption spectra of metallic derivatives of benzoylcamphor

1931 ◽  
Vol 132 (820) ◽  
pp. 387-397 ◽  
Keyword(s):  
Absorption Band ◽  
Absorption Spectra ◽  
Preceding Paper ◽  
Ultra Violet ◽  
Cupric Ion ◽  
Metallic Salts ◽  
Infra Red ◽  
Acids And Bases ◽  
Definition Of ◽  
Derivatives Of

In the preceding paper of the present series on “Absorption Spectra and Co-ordination of some Cupric Compounds” observations were recorded of the absorption spectra, in the infra-red, visible and ultra-violet regions, of a series of metallic derivatives of copper, ranging from typical metallic salts, such as the blue aqueous sulphate and nitrate, through the blue-green acetate and its homologues, to the violet, yellow or brown derivatives of various β-diketones. In spite of the wide differences of colour in these compounds, the variations were found to be due to a mere displacement of a single absorption band, e. g ., from 9600 Å. U. in K 2 CuCl 4 to 6000 Å. U. in [Cu. 4NH 3 SO 4 , and the conclusion was drawn that the cupric ion in all these compounds exhibits a fourfold co-ordination, either with the anions of the salt or with molecules of the solvent. In the present paper analogous methods have been applied to the study of the metallic derivatives of benzoylcamphor. The investigation had its origin in a suggested correlation between the phenomena of dynamic isomerism in prototropic compounds and of co-ordination in their metallic derivatives. The former phenomenon was attributed, on the basis of an extended definition of acids and bases,† to the possibility of separating a proton from two alternative positions in the molecule, giving rise to two isomeric anions, which could be converted into one another through an intermediate multipolar ion, e. g ., HO.C=C─⇌ - O─C─C-⇌ - O─ + | | | | Enol. Enolic anion. C─ - C─⇌O=C─ - C─⇌O=C─C─ | | | | | | Multipolar ion. Ketonic anion. Ketone. H

Torsional absorption spectra of long-chain substances in the solid state

1961 ◽  
Vol 264 (1317) ◽  
pp. 212-220 ◽  
Keyword(s):  
Solid State ◽  
Absorption Spectra ◽  
Intermolecular Forces ◽  
The Other ◽  
Torsional Vibrations ◽  
Chain Molecules ◽  
Absorption Intensity ◽  
Infra Red ◽  
Long Chain ◽  
Isolated Molecules

The absorption spectra connected with the torsional vibrations of long-chain substances are calculated. Ketones are treated in detail, but the results can also be applied to other long-chain molecules with simple dipolar groups. It is shown that the torsional frequencies of a long-chain ketone are very similar to those of the parent hydrocarbon. But the presence of the ketone group makes the vibrations active in the spectrum. For a molecule with L carbon atoms there are L — 3 torsional vibrations. For isolated molecules in the plane configuration, the frequencies range from a maximum d ) m in the far infra-red, down to low values. For an asymmetric ketone all the torsional frequencies are active, while for a symmetric ketone only half of them are active. However, the absorption intensity for frequencies near w m is expected to be very weak. In the solid state, the high and medium torsional frequencies are hardly affected by intermolecular interaction. In this region, therefore, the frequencies calculated for isolated molecules should be approximately correct. The low torsional frequencies, on the other hand, are strongly affected by intermolecular forces in the solid. This effect is discussed, and the absorption due to rigid libration of the molecules is also considered.

Infra-red and the Near Ultra-violet Absorption Spectra of Polypheny, Derivatives of the Elements of Groups IVb and Vb

Nature ◽  
1959 ◽  
Vol 183 (4673) ◽  
pp. 1475-1476 ◽  
Author(s):  
C. N. R. RAO ◽  
J. RAMACHANDRAN ◽  
M. S. C. IAH ◽  
S. SOMASEKHARA ◽  
T. V. RAJAKUMAR
Keyword(s):  
Absorption Spectra ◽  
Ultra Violet ◽  
Infra Red ◽  
Derivatives Of

Optical properties of a thin layer of the Vanadium dioxide at the metal state

2015 ◽  
Vol 9 (1) ◽  
pp. 2303-2310
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Optical Properties ◽  
Thin Layer ◽  
Vanadium Dioxide ◽  
Ultra Violet ◽  
Index Of Refraction ◽  
Cost Of Energy ◽  
Infra Red ◽  
Metal State ◽  
The Cost ◽  
Reversible Phase

The vanadium dioxide VO₂ currently became very motivating for the nanotechnologies’ researchers. It makes party of the intelligent materials because these optical properties abruptly change semiconductor state with metal at a critical  temperature θ = 68°C. This transition from reversible phase is carried out from a monoclinical structure characterizing its semiconductor state at low temperature towards the metal state of this material which becomes tétragonal rutile for  θ ˃ 68°C ; it is done during a few nanoseconds. Several studies were made on this material in a massive state and a thin layer. We will simulate by Maple the constant optics of a thin layer of VO₂ thickness z = 82 nm for the metal state according to the energy ω of the incidental photons in the energy interval: 0.001242 ≤ ω(ev) ≤ 6, from the infra-red (I.R) to the ultra-violet (U.V) so as to be able to control the various technological nano applications, like the detectors I.R or the U.V,  the intelligent windows to  increase  the energy efficiency in the buildings in order to save the cost of energy consumption by electric air-conditioning and the paintings containing nano crystals of this material. The constant optics, which we will simulate, is: the index of refraction, the reflectivity, the transmittivity, the coefficient of extinction, the dielectric functions ԑ₁ real part and  ԑ₂  imaginary part of the permittivity complexes ԑ of this material and the coefficient absorption. 

Optical properties of the Vanadium dioxide

2015 ◽  
Vol 8 (2) ◽  
pp. 2148-2155 ◽  
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Energy Efficiency ◽  
Optical Properties ◽  
Critical Temperature ◽  
Thin Layer ◽  
Dielectric Function ◽  
Vanadium Dioxide ◽  
Ultra Violet ◽  
Index Of Refraction ◽  
Practical Utility ◽  
Infra Red

The vanadium dioxide is a material thermo chromium which sees its optical properties changing at the time of the transition from the phase of semiconductor state ↔ metal, at a critical temperature of 68°C. The study of the optical properties of a thin layer of VO₂ thickness 82 nm, such as the dielectric function, the index of refraction, the coefficient ofextinction, the absorption’s coefficient, the reflectivity, the transmittivity, in the photonic spectrum of energy ω located inthe interval: 0.001242 ≤ ω (ev) ≤ 6, enables us to control well its practical utility in various applications, like the intelligentpanes, the photovoltaic, paintings for increasing energy efficiency in buildings, detectors of infra-red (I.R) or ultra-violet(U.V). We will make simulations with Maple and compare our results with those of the literature

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