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:	DOI: 10.1107/S0108768111004290; PubMed: 21422615; 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:	Organic crystal; Pharmaceutical applications; Reverse Transformation; Reversible phase transition; Single crystal x-ray diffraction; Solid state transformations; Space Groups; Temperature range; X-ray powder; Cooling; Crystal symmetry; Differential scanning calorimetry; Diffraction; Hydrogen; Hydrogen bonds; Molecules; Phase transitions; Single crystals; Twinning; X ray diffraction; X ray powder diffraction; 4 chloro N (propylaminocarbonyl)benzenesulfonamide; 4-chloro-N-(propylaminocarbonyl)benzenesulfonamide; propylamine; sulfonamide; article; chemical structure; chemistry; cold; conformation; differential scanning calorimetry; hydrogen bond; phase transition; thermodynamics; X ray crystallography; X ray diffraction; Calorimetry, Differential Scanning; Chlorpropamide; Cold Temperature; Crystallography, X-Ray; Hydrogen Bonding; Molecular Conformation; Molecular Structure; Phase Transition; X-Ray Diffraction; Thermodynamics; Sulfonamides; Propylamines; chlorpropamide; Conformations; chlorpropamide; twinning; polymorphism; phase transition; molecular conformations; hydrogen bonds; Molecular conformation; chlorpropamide;
Издано:	2011
Физ. характеристика:	с.163-176