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On substituted pyrazole derivatives. I. 3‐Methyl‐4‐[( Z )‐2‐(4‐methylphenyl)hydrazin‐1‐ylidene]‐1‐(3‐nitrophenyl)‐1 H ‐pyrazol‐5(4 H )‐one and 3‐methyl‐4‐[( Z )‐2‐(4‐methylphenyl)hydrazin‐1‐ylidene]‐1‐[4‐(trifluoromethyl)phenyl]‐1 H ‐pyrazol‐5(4 H )‐one
Author(s) -
AlvarezThon Luis,
Bustos Carlos,
Molins Elies,
Garland Maria Teresa,
Baggio Ricardo
Publication year - 2014
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/s2053229614017173
Subject(s) - tautomer , pyrazole , intramolecular force , chemistry , hydrogen bond , supramolecular chemistry , stereochemistry , acceptor , medicinal chemistry , molecule , crystallography , crystal structure , organic chemistry , physics , condensed matter physics
The title substituted pyrazole derivatives, C 17 H 15 N 5 O 3 and C 18 H 15 F 3 N 4 O, share most of their molecular features, in particular the hydrazinylidene (–HN—N=) rather than the diazene (–N=N–) tautomeric form, and differ only in the substituents (NO 2 and CF 3 ) on one of the outer phenyl rings. The molecular units are basically planar, with the rotation of the phenyl rings being hindered by the presence of two intramolecular hydrogen bonds having the keto O atom as acceptor. In both structures, the packing is governed by weak C—H...O, C—H...π and π–π interactions. The subtle way in which minor structural differences lead to rather different supramolecular structures is analysed.