Annamalai Subashini

A new chalcone structure of (E)-1-(4-Bromophenyl)-3-(napthalen-2-yl)prop-2-en-1-one: Synthesis, structural characterizations, quantum chemical investigations and biological evaluations.

The structure of (E)-1-(4-Bromophenyl)-3-(napthalen-2-yl)prop-2-en-1-one (C19H13BrO) crystallized in the triclinic system of P-1 space group. The unit cell dimensions are: a=5.8944 (9)Å, b=7.8190 (12)Å, c=16.320 (2)Å, α=102.4364 (19)°, β=95.943 (2)°, γ=96.274 (2)° and Z=2. The physical properties of this compound was determined by the spectroscopic methods (FTIR and (1)H and (13)C NMR). Quantum chemical investigations have been employed to investigate the structural and spectral properties. The molecular structure, vibrational assignments, (1)H and (13)C NMR chemical shift values, non-linear optical (NLO) effect, HOMO-LUMO analysis and natural bonding orbital (NBO) analysis were calculated using HF and DFT/B3LYP methods with 6-311++G(d,p) basis set in the ground state. The results show that the theoretical calculation of the geometrical parameters, vibrational frequencies and chemical shifts are comparable with the experimental data. The crystal structure is influenced and stabilized by weak C-H⋯π interactions connecting the molecules into infinite supramolecular one dimensional ladder-like arrangement. Additionally, this compound is evaluated for their antibacterial activities against gram positive and gram negative strains using a micro dilution procedure and shows activities against a panel of microorganisms.

Synthesis, crystal structure and theoretical studies of a Schiff base 2-[4-hydroxy benzylidene]-amino naphthalene.

The molecular structure of a new Schiff base, 2-[4-hydroxy benzylidene]-amino naphthalene (HBAN) has been examined by HF and B3LYP/6-311++G(d,p) calculations. The X-ray structure was determined in order to establish the conformation of the molecule. The compound, C17H13NO, crystallizes in the orthorhombic, P212121 space group with the cell dimension, a=6.2867(2), b=10.2108(3), c=19.2950(6) Å, α=β=γ=90° and z=4. The asymmetric unit contains a molecule of a Schiff base. A strong intermolecular O-H⋯N and a weak C-H⋯O hydrogen bonds stabilized the crystal structure. The vibrational spectra of HBAN have been calculated using density functional theoretical computation and compared with the experimental. The study is extended to the HOMO-LUMO analysis to calculate the energy gap (Δ), Ionization potential (I), Electron Affinity (A), Global Hardness (η), Chemical Potential (μ) and Global Electrophilicity (w). The calculated HOMO and LUMO energy reveals that the charge transfer occurs within the molecule.

2-Amino-4,6-dimethyl-pyrimidinium 3,5-dinitro-benzoate dihydrate.

In the title compound, C6H10N3 +·C7H3N2O6 −·2H2O, the aminopyrimidine molecule is protonated at one of the pyrimidine N atoms. The carboxylate group of the 3,5-dinitrobenzoate anion interacts with the protonated pyrimidine N atom and the 2-amino group through a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) motif. Two inversion-related pyrimidine rings are linked via a pair of N—H⋯N hydrogen bonds, also forming an R 2 2(8) ring motif.

catena-Poly[bis­(sulfamethoxazolium) [[trichloridocadmate(II)]-μ-chlorido] monohydrate]

In the title compound, {(C10H12N3O3S)2[CdCl4]·H2O}n, the CdII atom is five-coordinate with a distorted trigonal–bipyramidal geometry formed by chloride ions. The Cd atom and two of the Cl atoms lie on a mirror plane. The cation is protonated on the amino group N atom; it is not coordinated to cadmium, but is hydrogen bonded to the chlorido ligands. Each water molecule bridges two chlorido ligands, generating ring motifs along the –Cd—Cl—Cd– chains. The isoxazole unit and the amide groups are linked through a pair of N—H⋯N hydrogen bonds. The crystal structure is stabilized by N—H⋯O, O—H⋯Cl, C—H⋯N, N—H⋯Cl and C—H⋯O hydrogen bonds.

Crystal structure of 3-acet-oxy-2-methyl-benzoic acid.

In the title molecule, C10H10O4, the carboxylic acid group is twisted by 11.37 (15)° from the plane of the benzene ring and the acetoxy group is twisted from this plane by 86.60 (17)°. In the crystal, molecules are linked by pairs of O—H⋯O hydrogen bonds, forming inversion dimers with the expected R 2 2(8) graph-set motif.

Crystal structure of 2-{[(2-chloro­phen­yl)imino]­meth­yl}phenol

In the title compound, C13H10ClNO, the dihedral angle between the planes of the aromatic rings is 51.42 (9)° and an intra-molecular O-H⋯N hydrogen bond closes an S(6) ring. The Cl atom and the N atom are syn. No directional inter-actions beyond van der Waals contacts are observed in the crystal.