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A novel crystal form of metacetamol: the first example of a hydrated form
Author(s) -
Zemtsova Viktoria M.,
Fedorov Alexey Yu.,
Fedorova Elizaveta A.,
Boa Callum,
Arkhipov Sergey G.,
Rychkov Denis A.,
Minkov Vasily S.,
Pulham Colin R.,
Boldyreva Elena V.
Publication year - 2019
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229619012981
Subject(s) - hydrogen bond , monoclinic crystal system , crystallography , molecule , crystallization , crystal structure , hemihydrate , water of crystallization , chemistry , ring (chemistry) , crystal (programming language) , materials science , inorganic chemistry , organic chemistry , gypsum , computer science , programming language , metallurgy
We report the crystal structure and crystallization conditions of a first hydrated form of metacetamol (a hemihydrate), C 8 H 9 NO 2 ·0.5H 2 O. It crystallizes from metacetamol‐saturated 1:1 ( v / v ) water–ethanol solutions in a monoclinic structure (space group P 2 1 / n ) and contains eight metacetamol and four water molecules per unit cell. The conformations of the molecules are the same as in polymorph II of metacetamol, which ensures the formation of hydrogen‐bonded dimers and R 2 2 (16) ring motifs in its crystal structure similar to those in polymorph II. Unlike in form II, however, these dimers in the hemihydrate are connected through water molecules into infinite hydrogen‐bonded molecular chains. Different chains are linked to each other by metacetamol–water and metacetamol–metacetamol hydrogen bonds, the latter type being also present in polymorph I. The overall noncovalent network of the hemihydrate is well developed and several types of hydrogen bonds are responsible for its formation.