Crystal structure, spectroscopic and theoretical studies on two Schiff base compounds of 2,6-dichlorobenzylidene-2,4-dichloroaniline and 2,4-dichlorobenzylidene-2,4-dichloroaniline

The crystal structures of two Schiff base compounds, 2,6-dichlorobenzylidene-2,4-dichloroaniline (1) and 2,4-dichlorobenzylidene-2,4-dichloroaniline (2) have been determined from single-crystal X-ray diffraction and characterized by FT-IR and (1)H NMR spectroscopy. The electronic structures of compounds 1 and 2 in the gas phase were computed by the density functional theory (DFT) method. The obtained theoretical results were supported by the crystallographic data. In addition, theoretical configurations of the title compounds were relaxed and studied in terms of the combined analysis of HOMO-LUMO energy gap, total density of states (DOS), molecular electrostatic potential (MEP), NMR spectra and harmonic vibrational frequencies.

Biochemical and biophysical properties of a novel homoisoflavonoid extracted from Scilla persica HAUSSKN

In this study isolation and structural elucidation of a homoisoflavonoid, 3-(3',4'-dihydroxybenzyl)-8-hydroxy-5,7-dimethoxychroman-4-one (Scillapersicone 1), is reported from Scilla persica HAUSSKN. The structure was solved by a single crystal X-ray analysis. The unit cell parameters are a=11.7676 (2)Å, b=20.1174 (4)Å, c=7.8645 (9)Å, β=93.544 (2)°, V=1858.23 (7)Å(3), monoclinic space group P21/c and four symmetry equivalent molecules in an unit cell. The structure was consistent with the UV, IR, 1D and 2D NMR, HRFAB-MS data. The optimized molecular geometry agrees closely that obtained from the single crystal X-ray crystallography. Furthermore, cytotoxicity of this compound was evaluated by MTT assay on AGS and WEHI-164 cancerous cell lines.

4-[(E)-(4-Eth-oxy-phen-yl)imino-meth-yl]phenol

In the title compound, C₁₅H₁₅NO₂, the dihedral angle between the benzene rings is 52.04 (5)° and the mol­ecule has an E conformation about the central C=N bond. In the crystal, mol­ecules are connected by O—H⋯N hydrogen bonds, forming zigzag chains along the b axis. The crystal packing also features weak C—H⋯O inter­actions.

(E)-4-[(4-Bromo-phen-yl)imino-meth-yl]-2-meth-oxy-phenol

In the crystal structure of the title compound, C₁₄H₁₂BrNO₂, the dihedral angle between the rings is 37.87 (10)° and the mol­ecule has an E conformation about the central C=N bond. In the crystal, mol­ecules are connected by inter­molecular O—H⋯N hydrogen bonds into zigzag chains running parallel to the b axis. The packing also features C—H⋯O inter­actions.