In:
Acta Crystallographica Section C Structural Chemistry, International Union of Crystallography (IUCr), Vol. 72, No. 5 ( 2016-05-01), p. 379-388
Abstract:
In order to examine the preferred hydrogen-bonding pattern of various uracil derivatives, namely 5-(hydroxymethyl)uracil, 5-carboxyuracil and 5-carboxy-2-thiouracil, and for a conformational study, crystallization experiments yielded eight different structures: 5-(hydroxymethyl)uracil, C 5 H 6 N 2 O 3 , (I), 5-carboxyuracil– N , N -dimethylformamide (1/1), C 5 H 4 N 2 O 4 ·C 3 H 7 NO, (II), 5-carboxyuracil–dimethyl sulfoxide (1/1), C 5 H 4 N 2 O 4 ·C 2 H 6 OS, (III), 5-carboxyuracil– N , N -dimethylacetamide (1/1), C 5 H 4 N 2 O 4 ·C 4 H 9 NO, (IV), 5-carboxy-2-thiouracil– N , N -dimethylformamide (1/1), C 5 H 4 N 2 O 3 S·C 3 H 7 NO, (V), 5-carboxy-2-thiouracil–dimethyl sulfoxide (1/1), C 5 H 4 N 2 O 3 S·C 2 H 6 OS, (VI), 5-carboxy-2-thiouracil–1,4-dioxane (2/3), 2C 5 H 4 N 2 O 3 S·3C 6 H 12 O 3 , (VII), and 5-carboxy-2-thiouracil, C 10 H 8 N 4 O 6 S 2 , (VIII). While the six solvated structures, i.e. (II)–(VII), contain intramolecular S (6) O—H...O hydrogen-bond motifs between the carboxy and carbonyl groups, the usually favoured R 2 2 (8) pattern between two carboxy groups is formed in the solvent-free structure, i.e. (VIII). Further R 2 2 (8) hydrogen-bond motifs involving either two N—H...O or two N—H...S hydrogen bonds were observed in three crystal structures, namely (I), (IV) and (VIII). In all eight structures, the residue at the ring 5-position shows a coplanar arrangement with respect to the pyrimidine ring which is in agreement with a search of the Cambridge Structural Database for six-membered cyclic compounds containing a carboxy group. The search confirmed that coplanarity between the carboxy group and the cyclic residue is strongly favoured.
Type of Medium:
Online Resource
ISSN:
2053-2296
DOI:
10.1107/S2053229616004861
DOI:
10.1107/S2053229616004861/eg3200sup1.cif
DOI:
10.1107/S2053229616004861/eg3200Isup2.hkl
DOI:
10.1107/S2053229616004861/eg3200IIsup3.hkl
DOI:
10.1107/S2053229616004861/eg3200IIIsup4.hkl
DOI:
10.1107/S2053229616004861/eg3200IVsup5.hkl
DOI:
10.1107/S2053229616004861/eg3200Vsup6.hkl
DOI:
10.1107/S2053229616004861/eg3200VIsup7.hkl
DOI:
10.1107/S2053229616004861/eg3200VIIsup8.hkl
DOI:
10.1107/S2053229616004861/eg3200VIIIsup9.hkl
DOI:
10.1107/S2053229616004861/eg3200Isup10.cml
DOI:
10.1107/S2053229616004861/eg3200IIsup11.cml
DOI:
10.1107/S2053229616004861/eg3200IIIsup12.cml
DOI:
10.1107/S2053229616004861/eg3200IVsup13.cml
DOI:
10.1107/S2053229616004861/eg3200Vsup14.cml
DOI:
10.1107/S2053229616004861/eg3200VIsup15.cml
DOI:
10.1107/S2053229616004861/eg3200VIIsup16.cml
DOI:
10.1107/S2053229616004861/eg3200VIIIsup17.cml
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2016
detail.hit.zdb_id:
2025703-X
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