TY - JOUR

T1 - A novel crystal form of metacetamol

T2 - The first example of a hydrated form

AU - Zemtsova, Viktoria M.

AU - Fedorov, Alexey Yu

AU - Fedorova, Elizaveta A.

AU - Boa, Callum

AU - Arkhipov, Sergey G.

AU - Rychkov, Denis A.

AU - Minkov, Vasily S.

AU - Pulhamd, Colin R.

AU - Boldyreva, Elena V.

N1 - Publisher Copyright: © 2019 International Union of Crystallography.

PY - 2019/11/1

Y1 - 2019/11/1

N2 - We report the crystal structure and crystallization conditions of a first hydrated form of metacetamol (a hemihydrate), C8H9ONO2·0.5H2O. It crystallizes from metacetamol-saturated 1:1 (v/v) water-ethanol solutions in a monoclinic structure (space group P21/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.

AB - We report the crystal structure and crystallization conditions of a first hydrated form of metacetamol (a hemihydrate), C8H9ONO2·0.5H2O. It crystallizes from metacetamol-saturated 1:1 (v/v) water-ethanol solutions in a monoclinic structure (space group P21/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.

KW - ACETAMINOPHEN

KW - API

KW - PARACETAMOL

KW - SOLUBILITY

KW - crystal packing

KW - crystal structure

KW - crystallization

KW - disorder

KW - hydrate

KW - hydrogen bond

KW - metacetamol

KW - motif

UR - http://www.scopus.com/inward/record.url?scp=85074548259&partnerID=8YFLogxK

U2 - 10.1107/S2053229619012981

DO - 10.1107/S2053229619012981

M3 - Article

C2 - 31686655

AN - SCOPUS:85074548259

VL - 75

SP - 1465

EP - 1470

JO - Acta Crystallographica Section C: Structural Chemistry

JF - Acta Crystallographica Section C: Structural Chemistry

SN - 2053-2296

ER -