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Dey D.,Indian Institute of Science | Prakash V.,Shirdi Sai Engineering College | Chopra D.,Indian Institute of Science | Vasu,Vivekananda Degree College | Srinivas M.,Biocon
Journal of Chemical Crystallography | Year: 2014

Two nitro substituted ethyl (2E)-2-cyano-3-phenylprop-2-enoate with molecular formula C12H10N2O4 have been synthesized and characterized by single-crystal X-ray diffraction. These two structures assemble via weak C-H···O=C/O (nitro group), C-H···N, and π-π intermolecular interactions which contribute towards the stability of the crystal packing. The lattice energies have been calculated using the PIXEL approach. Furthermore, high level DFT + Disp calculations for comparison with the pairing energies obtained from PIXEL method have been performed. An analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions, which are the key elements in building different supramolecular architectures. Graphical Abstract: The manuscript highlights the evaluation of molecular conformation and crystal packing in two nitro derivatives of ethyl (2E)-2-cyano-3-phenylprop-2-enoate. 1. Molecular conformation in the solid state and compared with that in the gas phase. 2. Vibrational frequency calculations using TURBOMOLE. 3. Lattice Energy calculations using PIXEL. 4. Hirshfeld surface analysis to investigate intermolecular calculations.[Figure not available: see fulltext.] © 2014 Springer Science+Business Media New York.

Darshan G.,Harvard Degree College | Vasu,Vivekananda Degree College | Chopra D.,Indian Institute of Science | Saravanan J.,JKK Nataraja Dental College and Hospital
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2010

The title isomers, viz. the N-(3-methylphenyl)-, (I), and N-(2-methylphenyl)-, (II), derivatives, both C26H28N 2O4S, adopt an E configuration that places the thio-phene and trimeth-oxy-phenyl groups on opposite sides of the C = N double bond, providing a suitable orientation for formation of an intra-molecular N - H⋯N hydrogen bond. However, while the mol-ecule in (I) is close to being planar, the N-methyl-phenyl group in (II) is twisted significantly from the plane of the remainder of the mol-ecule. Both crystal structures are essentially layered and there are no inter-molecular N - H⋯O hydrogen bonds. Compound (I) has a significantly higher calculated density than (II) (1.340 cf 1.305 Mg m-3), indicating that the mol-ecular packing in the meta isomer is overall more efficient than that in the ortho isomer. © 2010 International Union of Crystallography.

Sharma P.,Jammu University | Anthal S.,Jammu University | Prakash V.,Shirdi Sai Engineering College | Vasu,Vivekananda Degree College | And 2 more authors.
X-ray Structure Analysis Online | Year: 2014

The title compound, 2-cyano-N-cyclohexylacetamide, C9H14N20, crystallizes in the monoclinic space group P21/n with the following unit-cell parameters: a = 12.057(2), b = 4.7671(8), c = 16.327(4)å, β = 96.50(2)°, Z = 4. The crystal structure was elucidated by direct methods, and refined to a final R-value of 0.0765 for 1137 observed reflections. The cyclohexane ring adopts the chair conformation. Intermolecular hydrogen bonds of the type N-H.O and C-H.N have been observed. © The Japan Society for Analytical Chemistry.

Nagabhushana H.,Tumkur University | Nagabhushana B.M.,M.S. Ramaiah Institute of Technology | Madesh Kumar M.,Cambridge Institute of Technology | Chikkahanumantharayappa,Vivekananda Degree College | And 4 more authors.
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2011

CaSiO3:Eu3+ (1-5 mol%) red emitting phosphors have been synthesized by a low-temperature solution combustion method. The phosphors have been well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical spectroscopy. PXRD patterns reveal monoclinic CaSiO3 phase can be obtained at 900 °C. The SEM micrographs show the crystallites with irregular shape, mostly angular. Upon 254 nm excitation, the phosphor show characteristic fluorescence 5D0 → 7F J (J = 0, 1, 2, 3, 4) of the Eu3+ ions. The electronic transition located at 614 nm corresponding to 5D0 → 7F2 of Eu3+ ions, which is stronger than the magnetic dipole transition located at 593 nm corresponding to 5D 0 → 7F1 of Eu3+ ions. Different pathways involved in emission process have been studied. Concentration quenching has been observed for Eu3+ concentration > 4 mol%. UV-visible absorption shows an intense band at 240 nm in undoped and 270 nm in Eu3+ doped CaSiO3 which is attributed to oxygen to silicon (O-Si) ligand-to-metal charge-transfer (LMCT) band in the SiO3 2- group. The optical energy band gap is widened with increase of Eu3+ ion dopant. © 2010 Elsevier B.V. All rights reserved.

Vijaya S.,Government First Grade College | Vasu,Vivekananda Degree College | Gowda K.V.A.,Government First Grade College | Narasimhamurthy T.,Indian Institute of Science | Rathore R.S.,University of Hyderabad
Acta Crystallographica Section E: Structure Reports Online | Year: 2011

The title compound, C 18H 16ClN 3S, adopts an extended mol-ecular structure. The thia-zole ring is inclined by 9.2 (1) and 15.3 (1)° with respect to the chloro-phenyl and 4-(Dimethylamino)-phenyl rings, respectively, while the benzene ring planes make an angle of 19.0 (1)°. A weak Intermolecular C - H⋯π contact is observed in the crystal structure.

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