A second monoclinic polymorph of 2-(diformylmethylidene)-3,3-dimethyl-2,3-dihydro-1H-indole

Khaledi, H. and Saharin, S.M. and Ali, Hapipah Mohd and Robinson, W.T. and Abdulla, Mahmood Ameen (2009) A second monoclinic polymorph of 2-(diformylmethylidene)-3,3-dimethyl-2,3-dihydro-1H-indole. Acta Crystallographica Section E: Structure Reports Online, 65. O2585. ISSN 1600-5368, DOI https://doi.org/10.1107/s1600536809038495.

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Abstract

The crystal structure of the title compound, C13H13NO2, is a polymorph of the structure first reported by Helliwell et al. [Acta Cryst. (2006), E62, o737-o738]. It is also monoclinic (space group P2(1)/c), but with completely different cell constants. The molecular conformations of these polymorphs differ by a 180 degrees rotation of one formyl group. The present molecule is planar [maximum deviation 0.089 (2) angstrom] with the exception of the two methyl groups which lie on either side of the plane. There are strong intra- and intermolecular N-H center dot center dot center dot O hydrogen bonds. The latter link pairs of molecules across crystallographic centers of symmetry. Two aldehyde O atoms are brought close together [2.896 (4) angstrom in this arrangement but are not hydrogen bonded. In the earlier polymorph, one formyl group is rotated by 180 degrees to yield intermolecular hydrogen bonding and an infinite polymeric chain. The other formyl group is involved in the same intramolecular hydrogen bonding as has been found here.

Item Type:	Article
Funders:	UNSPECIFIED
Additional Information:	Department of Chemistry, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA
Subjects:	Q Science > QD Chemistry
Divisions:	Faculty of Science > Department of Chemistry
Depositing User:	Miss Malisa Diana
Date Deposited:	05 Apr 2013 01:50
Last Modified:	31 Jan 2019 04:33
URI:	http://eprints.um.edu.my/id/eprint/5386

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