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Pianka, M. (1955) Light absorption and other properties of carbocyanines and certain phosphorus containing compounds. Doctoral thesis, Northern Polytechnic.
In a short Introductory and Historical Part the effect of substituents on the light absorption of organic compounds is briefly discussed; the chemistry of Carbocyanines and of certain organophosphorus compounds of the anhydride structure, their biological activity and light absorption are reviewed. This is followed by an experimantal Part giving the preparation of certain asines; of various heterocyclic bases; of their anilinovinyl-, anilinopropenyl-, and anilinebutenyl- derivatives; and of symmetrical and unsymmetrical meso-substituted carbocyanines. Many of these compounds have not previously been prepared. An account follows of the reactivity of organic phosphorohalogenides towards inorganic bases, and towards aqueous pyridine. An addition compound between dimethylphosphoramidio dichloride and hexamethyl phosphoramide is described, and then the kinetics of a radical exchange (NMe2 for Cl) leading to the formation of tetramethylphosphorodiemidic chloride. In the third Part (Discussion) the reactions leading to the formation of the carbocyanines, also the effect of substitution on the reactivity of phosphorohalogenides are discussed. Correlation between fungitoxio properties of the carbocyanines, discovered in the course of this work, and their chemical structure is sought. The biological activity of organophosphorus Geepounds is related with their chemical reactivity. The ultra-violet absorption of a answer of asines, the light absorption of carbocyanines in methanol, and the ultra-violet absorption of certain organophosphorus compounds in a non-polar solvent are then described.T he hypsochromic shifts, which the absorption maxima of thia- and selena-carbocyanines undergo on meso-alkyl substitution, cannot bo explained by sterio hindrance. The shifts can be caused also by other substituents. The hypscohromio shifts can be explained on the basis of the hyperconjugative effect of the alkyl group [or suitable mesomeric (+M) effect of other groups] which would allow the positive charge on the meso-carbon atom to migrate out of the main conjugation path, thus stabilising the ground state of the carbocyanine. The hyperconjugative jugative effect can be annulled by hydrogen bonding - 4 - (as in oxacarbocyanines). The hyperconjugative effect of alkyl groups in this- and selena-carbocyanines, and of 2:4-dinitrophenylhydraxones of a homlogous series of aliphatic aldehydes is compared with their chemical effect upon the hydrolysis of diphenylmethyl chlorides. Also the stabilisation energy due to the alkyl groups in this- and selena-carbocyanines forming the subject of this study, and in the dinitrophenylhydrazones is evaluated from their absorption spectra. The effect of replacing chlorine by fluorine, dimethylamino- by an ethoxy- group and phosphoryl by thiophoephoryl group on the ultra-violet light absorption of certain phosphoramidetes and pyrophosphates is critically discussed. In the course of this work many now compounds have been synthesised and a number of Improved methods of preparation found and developed. The Discussion is followed by the final Part: Conclusions (Summary)
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