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Rizwana Begum S.,Seethalakshmi Ramaswami College Autonomous | Venkateswaramoorthi R.,Annamalai University | Krishnasamy K.,Annamalai University | Anitha A.G.,Seethalakshmi Ramaswami College Autonomous
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The asymmetric unit of the title compound, C22H23F2NO, contains two independent molecules, A and B. The bicyclic system adopts a twin-chair conformation in both molecules. The dihedral angles between the fluorophenyl rings are 55.27 (8) and 56.37 (7)° in molecules A and B, respectively. The NH groups are not involved in hydrogen bonding due to the steric hindrance of fluorophenyl groups. The crystal structure features weak C - H⋯O interactions.


Srinivasan N.,P.A. College | Rizwana Begum S.R.A.,Seethalakshmi Ramaswami College Autonomous | Sridhar B.,Indian Institute of Chemical Technology | Anitha A.G.,Seethalakshmi Ramaswami College Autonomous
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The asymmetric unit of the title compound, C18H 16F2N2·H2O, contains two independent molecules (A and B), and two independent water molecules of crystallization. In molecule A, the imidazole ring makes dihedral angles of 47.46(7) and 60.98(6)° with the 2,4-difluorophenyl and methylphenyl rings, respectively. The corresponding angles in molecule B are 45.85(7) and 62.78(7)°, respectively. The dihedral angle between the two benzene rings is 64.98(7)° in molecule A and 65.53(7)° in molecule B. In the crystal, the two independent molecules are linked by O - H⋯N and O - H⋯O hydrogen bonds, forming chains propagating along [100]. These chains are linked via C - H⋯F hydrogen bonds, forming slab-like two-dimensional networks lying parallel to (001).


PubMed | P.A. College and Seethalakshmi Ramaswami College Autonomous
Type: Journal Article | Journal: Acta crystallographica. Section E, Structure reports online | Year: 2014

In the title compound, C18H17FN2O, the imidazole ring makes dihedral angles of 68.81(6) and 25.20(8) with the meth-oxy-phenyl and fluoro-phenyl rings, respectively. The dihedral angle between the meth-oxy-phenyl and fluoro-phenyl ring is 71.89(6). In the crystal, mol-ecules are linked into inversion dimers with an R 2 (2)(8) graph-set motif by pairs of weak C-HF inter-actions.


PubMed | P.A. College, Sri Krishna College of Engineering And Technology, Seethalakshmi Ramaswami College Autonomous and Annamalai University
Type: Journal Article | Journal: Acta crystallographica. Section E, Structure reports online | Year: 2014

In the title compound, C23H24F2O3, the central pyran ring has a flat-boat conformation, whereas the two fused cyclo-hexenone rings adopt envelope conformations, with the C atom bearing the dimethyl substituent being the flap atom in each case. The pyran ring mean plane and the di-fluoro-phenyl ring are almost normal to each other, making a dihedral angle of 87.55(4). In the crystal, mol-ecules are linked by pairs of C-HO hydrogen bonds, forming inversion dimers with an R 2 (2)(8) ring motif. The F atom at position 2 on the di-fluoro-phenyl ring is disordered over the 2- and 6-positions, and has a refined occupancy ratio of 0.932(3):0.068(3).


Venkateswaramoorthi R.,Annamalai University | Rizwana Begum S.,Seethalakshmi Ramaswami College Autonomous | Hema R.,Seethalakshmi Ramaswami College Autonomous | Krishnasamy K.,Annamalai University | Anitha A.G.,Seethalakshmi Ramaswami College Autonomous
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the title compound, C18H21NO3, the bicyclic ring system adopts a twin-chair conformation. The two methyl groups attached to the bicycle are in an equatorial orientation for both rings. One of the furan rings is disordered over two orientations with an occupancy ratio of 0.686 (6):0.314 (6). In the crystal, very long N - H⋯O hydrogen bonds connect the molecules into a chain perpendicular to the ac plane.


Rizwana Begum S.,Seethalakshmi Ramaswami College Autonomous | Hema R.,Seethalakshmi Ramaswami College Autonomous | Srinivasan N.,P.A. College | Anitha A.G.,Seethalakshmi Ramaswami College Autonomous
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

In the title compound, C18H18N2O, the imidazole ring makes dihedral angles of 68.26 (7) and 22.45 (9)° with the methoxyphenyl and phenyl rings, respectively. The dihedral angle between the methoxyphenyl and phenyl ring is 71.86 (7)°. In the crystal, weak intermolecular C - H...O and C - H...N hydrogen bonds link the molecules into columns propagated in [101].


Santhi S.,Seethalakshmi Ramaswami College Autonomous
Asian Journal of Chemistry | Year: 2012

Kinetics of oxidation of N-methyl-2,6-diphenyl piperidin-4-one and its 3-alkyl substituted derivatives by acid dichromate has been studied in aqueous acetic acid medium. The oxidation is first order with respect to [oxidant] and [substrate]. The reactions are acid catalyzed. Ionic strength has no appreciable effect on the reaction rate. The reaction rate decreases with decrease in the dielectric strength of the medium indicating a polar mechanism. The reactions followed at four different temperatures and the activation parameters computed. Based on the results obtained a suitable mechanism is proposed. The reactivity sequence is found to be 1,3,5-trimethyl PPO > 1-methyl PPO > 1,3-dimethyl PPO > 1-methyl-3-ethyl PPO > 1-methyl-3-isopropyl PPO.


Jani Bai T.S.,Seethalakshmi Ramaswami College Autonomous | Santhi S.,Seethalakshmi Ramaswami College Autonomous
Asian Journal of Chemistry | Year: 2010

The oxidative deoximation of 1-methyl-2,6-diphenyl piperidin-4-one and its 3-alkyl substituted derivatives by pyridinium chlorochromate (PCC) in aqueous acetic acid medium exhibits a first order dependence on both the oxime and PCC. The reactions are catalyzed by hydrogen ions. The rates are accelerated by increasing the dielectric strength of the medium. The activation parameters are computed by performing the reactions at four different temperatures. On the basis of the experimental results a suitable mechanism has been proposed. The reactivity trend observed for the oximes is 1-MePPO > 1,3-diMe2PPO > 1-Me-3-EtPPO > 1,3,3-Me3PPO > 1-Me-3-iprPPO.


PubMed | Seethalakshmi Ramaswami College Autonomous
Type: Journal Article | Journal: Acta crystallographica. Section E, Structure reports online | Year: 2013

In the title compound, C18H18N2O, the imidazole ring makes dihedral angles of 68.26(7) and 22.45(9) with the meth-oxy-phenyl and phenyl rings, respectively. The dihedral angle between the meth-oxy-phenyl and phenyl ring is 71.86(7). In the crystal, weak inter-molecular C-HO and C-HN hydrogen bonds link the mol-ecules into columns propagated in [101].


PubMed | Seethalakshmi Ramaswami College Autonomous
Type: Journal Article | Journal: Acta crystallographica. Section E, Structure reports online | Year: 2013

The asymmetric unit of the title compound, C22H23F2NO, contains two independent mol-ecules, A and B. The bicyclic system adopts a twin-chair conformation in both mol-ecules. The dihedral angles between the fluoro-phenyl rings are 55.27(8) and 56.37(7) in mol-ecules A and B, respectively. The NH groups are not involved in hydrogen bonding due to the steric hindrance of fluoro-phenyl groups. The crystal structure features weak C-HO inter-actions.

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