Abstract
The geometry of the title mol-ecule [systematic name: 2-(2-nitro-phen-yl)-4H-chromen-4-one], C15H9NO4, is determined by two dihedral angles formed by the mean plane of phenyl ring with the mean planes of chromone moiety and nitro group, being 50.73 (5) and 30.89 (7)°, respectively. The crystal packing is determined by π-π inter-actions and C-H⋯O contacts. The results of DFT calculations at the B3LYP/6-31G* level of theory provided an explanation of the unusually large dihedral angle between the chromone moiety and the phenyl group. The electrostatic potential map on the mol-ecular surface was calculated in order to determine the potential binding sites to receptors.
Highlights
DÁ Á ÁA ecule of 20-methoxyflavone was reported to be almost planar, with a dihedral angle of 2.9 (Wallet et al, 1990)
The unusually large dihedral angle in the title molecule can be attributed to the steric tension between the nitro group and the chromone oxygen atom, whereas in the carbazole derivative this substituent is twisted far enough from the plane of the benzene ring to avoid it coming into close proximity with the flavone core
The presence of – interactions in the crystal packing can be suggested from the short intermolecular distance of 3.299 (4) Abetween the overlapping C9 atoms from opposing molecules
Summary
The naturally occurring group of heterocyclic compounds known as flavonoids has received considerable attention over the past 15 years. The synthesis and applications of flavones and their derivatives have been studied extensively because of their diverse pharmaceutical properties Besides their physiological role in plants (Agati et al, 2012), this class of compounds has demonstrated antiallergic, antiviral, anxiolytic and anti-inflammatory activities (Manthey et al, 2001). Several nitro derivatives of flavones have been reported to possess antiproliferative properties against human and murine cancerous cells, by the mechanism of induced apoptosis (Blank et al, 2004). The unusually large dihedral angle in the title molecule can be attributed to the steric tension between the nitro group and the chromone oxygen atom, whereas in the carbazole derivative this substituent is twisted far enough from the plane of the benzene ring to avoid it coming into close proximity with the flavone core
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