Головна Головна -> Реферати українською -> Дисертації та автореферати -> Українською реферат: Спектроскопія ЯМР молекул з структурно напруженими фрагментами та групами з загальмованим внутрішнім обертанням

Спектроскопія ЯМР молекул з структурно напруженими фрагментами та групами з загальмованим внутрішнім обертанням / сторінка 12

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Спектроскопія ЯМР молекул з структурно напруженими фрагментами та групами з загальмованим внутрішнім обертанням
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Реферат
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Українська
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–Manuscript.
The dissertation for candidate's degree in chemistry in the speciality 02.00.04 – physical chemistry. Institute of physic, organic and coal chemistry NAS of Ukraine. 2008.
The dissertation develops fragmentary model of shielding scheme NMR-1Н and 13С interpretation in the decision of problems of a spatial structure, conformation and stereoisomeric structure of structurally rigid molecules and conformatively labile structures.
Mechanisms of complication of a spectral picture in NMR-1Н and 13С spectra of amides and hydrazides of carboxylic acids were defined. Was shown, that the major factor of complication of spectral picture under influence of conformation transitions in several amid fragments, is the redistribution of electronic density in a molecule, connected with mutual influence of internal dynamics of separate conformatively labile groups. Was shown, that distinction in chemical shifts of each atom of carbon of Z and Е conformers in NMR-13С spectra of amides and hydrazides of carboxylic acids in the characteristic image depends on its remoteness from fragment C(O)-NH on a circuit of bonds for each carbon atom in a molecule. On the basis of assumptions of existence of dependence between electronic density on an amid proton and C-N bond’s order in the C(O)-NH fragment and consequently also height of a barrier of rotation in the amid fragment, the scheme of estimation of difference in electronic density of NH proton at change of conformation in amid fragment was offered. The offered scheme based in using of constants of conformation balance.
By the methods of NMR spectroscopy was shown, that in reaction of endo-dicyclopentadiene with dichlorcarbene the product of connection is formed only on one of two double bonds. The structure of monoadduct of endo-dicyclopentadiene and dichlorcarbene as a product of connection on a double bond in fifth member cycle with trans-orientation of norbornene and cyclopropane framework was established.
Keywords: NMR spectroscopy, chemical shift, amides and hydrazides of carboxylic acids, polycyclic hydrocarbons

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Реферат на тему: Спектроскопія ЯМР молекул з структурно напруженими фрагментами та групами з загальмованим внутрішнім обертанням

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