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

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

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.

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
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