ISSN:
1600-5759
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Although the two polymorphic modifications, (I) and (II), of the title compound, C13H10N2O, crystallize in the same space group (P21/c), their asymmetric units have Z′ values of 1 and 2, respectively. These are conformational polymorphs, since the molecules in phases (I) and (II) adopt different rotations of the phenyl ring with respect the central 2-cyanocarboxyaminoprop-2-enyl fragment. Calculations of crystal packing using Cerius2 [Molecular Simulations (1999). 9685 Scranton Road, San Diego, CA 92121, USA] have shown that (I) is more stable than (II), by 1.3 kcal mol−1 for the crystallographically determined structures and by 1.56 kcal mol−1 for the optimized structures (1 kcal mol−1 = 4.184 kJ mol−1). This difference is mainly attributed to the different strengths of the hydrogen bonding in the two forms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S010827010100909X
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