Metamorphosis of caffeine hydrate and anhydrous caffeine
Metamorphosis of caffeine hydrate and anhydrous caffeine
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DOI：
10.1039/a702041d
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发表时间：
1997-10-01
期刊：
影响因子：
--
通讯作者：
York, P
中科院分区：
文献类型：
--
作者：
Edwards, HGM;Lawson, E;York, P
咖啡因（1，3，7-三甲基嘌呤-2，6-二酮）水合物和无水咖啡因的相稳定性、相互转化和物理化学表征与可用氢键的强度有关。水合物分子的氢键T-分支脊柱为咖啡因水合物建立弱晶格键，其在环境条件下转化为β-无水相，其在155 ° C和3.6 kJ mol（-1）的焓下转化为三角相α-无水咖啡因。无水相通过弱CH 3至CO氢键稳定。
The phase stability, interconversion and physicochemical characterisation of caffeine (1,3,7-trimethyl-purine-2,6-dione) hydrate and anhydrous caffeine relate to the strength of the available hydrogen-bonds. A hydrogen-bonded T-branched spine of hydrate molecules establishes a weak lattice bond for the caffeine hydrate which, under ambient conditions, transforms to a beta-anhydrous phase which in turn, at 155 degrees C and with an enthalpy of 3.6 kJ mol(-1), converts to a trigonal phase alpha-anhydrous caffeine. The anhydrous phases are stabilised by weak CH3 to CO hydrogen bonds.