Инд. авторы:	Drebushchak T.N., Drebushchak V.A., Boldyreva E.V.
Заглавие:	Solid-state transformations in the β-form of chlorpropamide on cooling to 100 K
Библ. ссылка:	Drebushchak T.N., Drebushchak V.A., Boldyreva E.V. Solid-state transformations in the β-form of chlorpropamide on cooling to 100 K // Acta Crystallographica. Section B: Structural Science. - 2011. - Vol.67. - Iss. 2. - P.163-176. - ISSN 0108-7681. - EISSN 1600-5740.
Внешние системы:	PubMed: 21422615; DOI: 10.1107/S0108768111004290; SCOPUS: 2-s2.0-79952910916;
Реферат:	eng: A single-crystal X-ray diffraction study of the effect of cooling down to 100 K on the β-form of chlorpropamide, 4-chloro-N-(propylaminocarbonyl) benzenesulfonamide, has revealed reversible phase transitions at 257 K and between 150 and 125 K: β (Pbcn, Z′ = 1) βII (P2/c, Z′ = 2) βIII (P2/n, a′ = 2a, Z′ = 4); the sequence corresponds to cooling. Despite changes in the space group and number of symmetry-independent molecules, the volume per molecule changes continuously in the temperature range 100-300 K. The phase transition at 257 K is accompanied by non-merohedral twinning, which is preserved on further cooling and through the second phase transition, but the original single crystal does not crack. DSC (differential scanning calorimetry) and X-ray powder diffraction investigations confirm the phase transitions. Twinning disappears on heating as the reverse transformations take place. The second phase transition is related to a change in conformation of the alkyl tail from trans to gauche in 1/4 of the molecules, regularly distributed in the space. Possible reasons for the increase in Z′ upon cooling are discussed in comparison to other reported examples of processes (crystallization, phase transitions) in which organic crystals with Z′ > 1 have been formed. Implications for pharmaceutical applications are discussed. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.
Ключевые слова:	Conformations; X-Ray Diffraction; Thermodynamics; Sulfonamides; Propylamines; chlorpropamide; twinning; polymorphism; phase transition; molecular conformations; hydrogen bonds; chlorpropamide; Phase Transition; Molecular Structure; Molecular Conformation; Hydrogen Bonding; Crystallography, X-Ray; Cold Temperature; Chlorpropamide; Calorimetry, Differential Scanning; X ray diffraction; X ray crystallography; thermodynamics; phase transition; hydrogen bond; differential scanning calorimetry; conformation; cold; chemistry; chemical structure; article; sulfonamide; propylamine; 4-chloro-N-(propylaminocarbonyl)benzenesulfonamide; 4 chloro N (propylaminocarbonyl)benzenesulfonamide; X ray powder diffraction; X ray diffraction; Twinning; Single crystals; Phase transitions; Molecules; Hydrogen bonds; Hydrogen; Diffraction; Differential scanning calorimetry; Crystal symmetry; Cooling; X-ray powder; Temperature range; Space Groups; Solid state transformations; Single crystal x-ray diffraction; Reversible phase transition; Reverse Transformation; Pharmaceutical applications; Organic crystal; chlorpropamide; Molecular conformation;
Издано:	2011
Физ. характеристика:	с.163-176