Steric Hindrance in the Solute-Solvent Interactions of 2-Substituted 4,5-Dimethoxypyridazin-3(2H)-ones: An Infrared Spectral and Theoretical Study

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Title:Steric Hindrance in the Solute-Solvent Interactions of 2-Substituted 4,5-Dimethoxypyridazin-3(2H)-ones: An Infrared Spectral and Theoretical Study
Creators:
Šamalíková, Mária
Perjéssy, Alexander
Liu, Quing
Loos, Dušan
Konečný, Václav
Dehne, Heinz
Sokolowski, Siegmar
Šusteková, Zora
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 67, 12, pp. 1790-1804
Uncontrolled Keywords:Solvent effects, Semiempirical and <i>ab initio</i> calculations, Solute-solvent interactions, Pyridazin-3(2<i>H</i>)-ones, IR spectroscopy, Steric effects, Interacting molecular species

Abstract

Infrared spectra for a series of 2-substituted 4,5-dimethoxypyridazin-3(2<i>H</i>)-ones (<strong>1</strong>) were measured in hexane (<i>n</i>-C<sub>6</sub>H<sub>14</sub>)-CHCl<sub>3</sub> and CH<sub>3</sub>CN-D<sub>2</sub>O binary mixtures. The solute-solvent interactions of pyridazinones <strong>1</strong> were studied by correlation of <i>v</i>(C=O) values with mole fractions of the less polar components of binary mixtures. The different solute-solvent interacting species were distinguished and compared with those for 3-methyl-4-phenylthiazol-2(3<i>H</i>)-one (<strong>2</strong>) and previously investigated 1-methylpyrrolidin-2-one (<strong>3</strong>). The steric effects of the substituents adjacent to the C=O group amplified by the geometrical requirements of the six-membered pyridazin-3(2<i>H</i>)-one ring appeared to be the main factor governing the existence of individual hydrogen-bonded species. The solute-solvent interactions are&nbsp;sterically most restricted in pyridazinones <strong>1</strong>, while in thiazolones <strong>2</strong> they are freer and almost comparable to those in the sterically least hindered 1-methylpyrrolidin-2-ones <strong>3</strong>. The above results were confirmed by inspection of calculated semiempirical AM1 and PM3 and <i>ab initio</i> 6-31G* geometrical data for methyl derivatives <strong>1h</strong>, <strong>2</strong> and <strong>3</strong>. <p>

Title:Steric Hindrance in the Solute-Solvent Interactions of 2-Substituted 4,5-Dimethoxypyridazin-3(2H)-ones: An Infrared Spectral and Theoretical Study
Creators:
Šamalíková, Mária
Perjéssy, Alexander
Liu, Quing
Loos, Dušan
Konečný, Václav
Dehne, Heinz
Sokolowski, Siegmar
Šusteková, Zora
Uncontrolled Keywords:Solvent effects, Semiempirical and <i>ab initio</i> calculations, Solute-solvent interactions, Pyridazin-3(2<i>H</i>)-ones, IR spectroscopy, Steric effects, Interacting molecular species
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:67
Number:12
Page Range:pp. 1790-1804
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20021790UNSPECIFIED
ID Code:2034
Item Type:Article
Deposited On:06 Feb 2009 17:15
Last Modified:06 Feb 2009 16:15

Citation

Šamalíková, Mária; Perjéssy, Alexander; Liu, Quing; Loos, Dušan; Konečný, Václav; Dehne, Heinz; Sokolowski, Siegmar; Šusteková, Zora (2002) Steric Hindrance in the Solute-Solvent Interactions of 2-Substituted 4,5-Dimethoxypyridazin-3(2H)-ones: An Infrared Spectral and Theoretical Study. Collection of Czechoslovak Chemical Communications, 67 (12). pp. 1790-1804. ISSN 0010-0765

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