Browsing by Author "Nethaji, Munirathinam"

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    2-Phenyl-5,7-bis(prop-2-en-1-yloxy)-4H-chromen-4-one
    (International Union of Crystallography, 2008-12-03) Nallasivam, Angannan; Nethaji, Munirathinam; Vembu, Nagarajan; Ragunathan, Venkatraman; Sulochana, Nagarajan
    In the title compound, C21H18O4, tthe dihedral angle between the chromene ring system and the pendant phenyl ring is 6.1 (1)°. The crystal structure is stabilized by an intermolecular C - H⋯O and C - H⋯π inter-actions.
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    5,7-Bis(benz-yloxy)-2-phenyl-4H-chromen-4-one
    (International Union of Crystallography, 2008-11-29) Nallasivam, Angannan; Nethaji, Munirathinam; Vembu, Nagarajan; Jaswant, Buckle; Sulochana, Nagarajan
    In the title compound, C29H22O4, the chromene ring is almost planar with a small puckering [0.143 (2) Å]. The crystal structure is stabilized by C - H⋯O and C - H⋯π inter-actions. Edge-to-face (centroid-centroid distances of 3.894 and 3.673 Å) and face-to-face (centroid-centroid distance of 3.460 Å) π-π-ring electron inter-actions are also observed. © 2008.
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    5,7-Dimeth-oxy-2-phenyl-4H-chromen-4-one
    (International Union of Crystallography, 2009-02-11) Nallasivam, Angannan; Nethaji, Munirathinam; Vembu, Nagarajan; Ragunathan, Venkatraman; Sulochana, Nagarajan
    The asymmetric unit of the title compound, C17H 14O4, contains two independent mol-ecules which differ in the relative orientations of the phenyl rings with repect to the essentially planar [maximum deviations of 0.029 (2) and 0.050 (2) Å in the two mol-ecules] chromene fused-ring system, forming dihedral angles of 10.3 (5) and 30.86 (5)° in the two mol-ecules. The crystal structure is stabilized by weak C - H⋯O and C - -H⋯π inter-actions, and π-π stacking inter-actions.
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    6,8-Dibromo-5-hydr-oxy-4-oxo-2-phenyl-4H-chromen-7-yl acetate
    (International Union of Crystallography, 2009-02-21) Nallasivam, Angannan; Nethaji, Munirathinam; Vembu, Nagarajan; Ragunathan, Venkatraman; Sulochana, Nagarajan
    In the title compound, C17H10Br2O5, the chromene ring is almost planar with minimal puckering [total puckering amplitude = 0.067 (4) Å]. The dihedral angle between chromeme ring system and phenyl ring is 3.7 (2)°. The crystal structure is stabilized by intermolecular C - H⋯O inter-actions and an intramolecular O - H⋯O hydrogen bond also occurs.
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    Dimethyl 2,2′-[(4-oxo-2-phenyl-4H-chromene-5,7-diyl)dioxy]diacetate: A more densely packed polymorph
    (International Union of Crystallography, 2009-01-14) Nallasivam, Angannan; Nethaji, Munirathinam; Vembu, Nagarajan; Jaswant, Buckle; Sulochana, Nagarajan
    The title mol-ecule, C21H18O8, crystallizes in two crystal polymorphs, see also Nallasivam, Nethaji, Vembu & Jaswant [Acta Cryst. (2009), E65, o314-o315]. The mol-ecules of both polymorphs differ by the conformation of the oxomethyl-acetate groups. The title mol-ecules are rather planar compared to the mol-ecules of the other polymorph. In the title mol-ecule, one of the oxomethyl-acetate groups is disordered (occupancies of 0.6058/0.3942). The structures of both polymorphs are stabilized by C - H⋯O and C - H⋯π inter-actions. Due to the planarity of the title mol-ecules and similar inter-molecular inter-actions, the title mol-ecules are more densely packed than those of the other polymorph.