Experimental and computational study of removal of methyl green and eosin yellow from aqueous solutions using novel sulfamic and sulfanilic acid grafted chitosan-epichlorohydrin -FeO nanocomposites.

Two novel chitosan-based adsorbents, sulfamic acid-chitosan-epichlorohydrin-FeO (HK-1) and sulfanilic acid-chitosan-epichlorohydrin-FeO (HK-2), were successfully synthesized and characterized by XRD, TGA, DSC, BET, and SEM techniques. The ability of the synthesized adsorbents for removing cationic Methyl Green (MG) and anionic Eosin Yellow (EY) from aqueous solutions was investigated at different solution pHs, adsorbent dosages, and contact times. The results showed a removal efficiency of 93.

Preparation of new bio-based chitosan/FeO/NiFeO as an efficient removal of methyl green from aqueous solution.

Modified chitosan with various functional groups has high potential as an efficient adsorbent in removing water pollution. In this study, new magnetic adsorbent, bio-based chitosan/FeO/NiFeO, was successfully prepared by green chemistry route involving mixing of chitosan as core moiety and FeO/NiFeO nanocomposite, and slow evaporation of solvent. Synthesized chitosan/FeO/NiFeO was characterized by FT-IR, TGA, XRD, VSM and FE-SEM.

New chitosan Schiff base and its nanocomposite: Removal of methyl green from aqueous solution and its antibacterial activities.

New chitosan Schiff base (CS-NB) and its CS-NB-NiFe nanocomposite have been prepared and characterized by FTIR spectroscopy, XRD, SEM and DSC. FT-IR spectra and XRD patterns revealed the preparation of chitosan Schiff base CS-NB and its CS-NB-NiFe nanocomposite. DSC demonstrated the endo and exothermic correspondence the evaporation of solvent and decomposition of pyranose ring, respectively.

4-Bromo-2-[({2-[(2-hy-droxy-eth-yl)amino]-eth-yl}imino)-meth-yl]phenol.

The new title Schiff base compound, CHBrNO, crystallizes in the monoclinic space group 2 with two independent mol-ecules in the asymmetric unit. It was prepared by the condensation reaction of 5-bromo-2-hy-droxy-benzaldehyde and amino-ethyl-ethano-lamine. There is an intra-molecular O-H⋯N hydrogen bond with an (6) ring motif.

4-(Di-phenyl-meth-oxy)-3-eth-oxy-benzaldehyde.

In the title compound, CHO, the dihedral angle between the aromatic rings linked by the methine group is 81.265 (4)° and the eth-oxy side chain adopts an extended conformation [C-O-C-C = 177.24 (10)°].

Synthesis of new chitosan Schiff base and its FeO nanocomposite: Evaluation of methyl orange removal and antibacterial activity.

New chitosan Schiff base (3EtO-4OH/Chit) and its 3EtO-4OH/Chit/FeO nanocomposite were synthesized and characterized by FTIR, H NMR, XRD, TGA, DSC and SEM. The result confirmed the preparation of 3EtO-4OH/Chit and its 3EtO-4OH/Chit/FeO nanocomposite. The efficiency of the prepared catalysts was studied for the methyl orange (MO) removal from aqueous solution.

Isolation, spectroscopic characterization, X-ray, theoretical studies as well as in vitro cytotoxicity of Samarcandin.

Samarcandin 1, a natural sesquiterpene-coumarin, was isolated as well as elucidated from F. assa-foetida which has significant effect in Iranian traditional medicine because of its medicinal attitudes. The crystal structure of samarcandin was determined by single-crystal X-ray structure analysis.

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.

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.

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

In the title compound, C(15)H(15)NO(2), the dihedral angle between the benzene rings is 52.04 (5)° and the mol-ecule has an E conformation about the central C=N bond. In the crystal, mol-ecules are connected by O-H⋯N hydrogen bonds, forming zigzag chains along the b axis.

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

In the crystal structure of the title compound, C(14)H(12)BrNO(2), the dihedral angle between the rings is 37.87 (10)° and the mol-ecule has an E conformation about the central C=N bond. In the crystal, mol-ecules are connected by inter-molecular O-H⋯N hydrogen bonds into zigzag chains running parallel to the b axis.

2-[(4-Meth-oxy-2-nitro-phen-yl)imino-meth-yl]phenol.

The crystal structure of the title compound, C(14)H(12)N(2)O(4), contains four crystallographically independent mol-ecules in the asymmetric unit. All the mol-ecules have similar conformations; the dihedral angles between the aromatic rings are 33.1 (1), 33.

[N,N'-Bis(2,3,4-trimeth-oxy-benzyl-idene)-ethane-1,2-diamine-κ(2)N,N']dibromido-mercury(II).

In the title compound, [HgBr(2)(C(22)H(28)N(2)O(6))], the Hg(II) ion is bonded to two Br(-) ions and two N atoms of the chelating Schiff base ligand in a distorted tetra-hedral geometry. The Schiff base ligand adopts an E,E conformation. The dihedral angle between the planes of the two halves of the central N,N'-dimethyl-ethylenediamine part of the ligand is 2.

[N,N'-Bis(2,6-dichloro-benzyl-idene)propane-1,3-diamine-κ(2)N,N']dibromidozinc.

In the title compound, [ZnBr(2)(C(17)H(14)Cl(4)N(2))], the Zn(II) ion is bonded to two bromide ions and two N atoms of the diimine ligand and displays a moderately distorted tetra-hedral coordination geometry. The Schiff base ligand acts as a chelating ligand and coordinates to the Zn(II) atom via two N atoms.

[4-Bromo-N-(pyridin-2-yl-methyl-idene)aniline-κ(2)N,N']iodido(triphenyl-phosphane-κP)copper(I).

In the title compound, [CuI(C(12)H(9)BrN(2))(C(18)H(15)P)], the Cu(I) ion is bonded to one I atom, one triphenyl-phosphane P atom and two N atoms of the diimine ligand in a distorted tetra-hedral geometry. The Schiff base acts as a chelating ligand and coordinates to the Cu(I) atom via two N atoms. In the diimine ligand, the dihedral angle between the pyridine and bromo-phenyl rings is 19.

(E)-2-Cyano-3-(2,3-dimeth-oxy-phen-yl)acrylic acid.

The asymmetric unit of the title compound, C(12)H(11)NO(4), contains two mol-ecules. In the crystal, neighbouring mol-ecules are linked together by O-H⋯O hydrogen bonds into dimers. The dimers are arranged into columns parallel to the a axis, meditated by π-π inter-actions [centroid-centroid distances = 3.

2-(3,4-Dimeth-oxy-phen-yl)-1H-benzimidazole.

In title compound, C(15)H(14)N(2)O(2), the dihedral angle between the 3,4-dimeth-oxy-phenyl group and the benzimidazole system is 26.47 (6)°. In the crystal, neighbouring mol-ecules are linked by N-H⋯N hydrogen bonds into C(4) chains propagating along the c-axis direction.

2-[4-(2-Formyl-phen-oxy)-but-oxy]-benzaldehyde.

In the crystal structure of the title compound, C(18)H(18)O(4), the full mol-ecule is generated by the application of an inversion centre. The mol-ecule is essentially planar, with an r.m.

Evidence for side-chain π-delocalization in a planar substituted benzene: an experimental and theoretical charge density study on 2,5-dimethoxybenzaldehyde thiosemicarbazone.

The charge density in 2,5-dimethoxybenzaldehyde thiosemicarbazone (1) has been studied experimentally using Mo-K(α) X-ray diffraction at 100 K, and by theory using DFT calculations at the B3LYP/6-311++G(2d,2p) level. The quantum theory of atoms in molecules (QTAIM) was used to investigate the extent of π-delocalization in the thioamide side-chain, which is virtually coplanar with the benzene ring. The experimental and theoretical ellipticity profiles along the bond paths were in excellent agreement, and showed that some of the formal single bonds in the side-chain have significant π-bond character.

Synthesis and Characterization of Two Diimine Schiff Bases Derived from 2,4-Dimethoxybenzaldehyde: The Crystal Structure of N,N'-Bis(2,4-dimethoxy-benzylidene)-1,2-diaminoethane.

Two diimine Schiff bases derived from 2,4-dimethoxybenzaldehyde; N,N'-bis(2,4-dimethoxybenzylidene)-1,2-diaminoethane (1) and N,N'-bis(2,4-dimethoxybenzylidene)-1,4-diaminobutane (2), were prepared and characterized by elemental analyses, FT-IR and 1H NMR spectroscopy. The crystal structure of 1 has been determined by single crystal X-ray diffraction. Its molecule adopts an E configuration with respect to the C=N bond and is located on a center of inversion with one half-molecule in the asymmetric unit.

(E)-N-(2,4-Dimeth-oxy-benzyl-idene)-4-ethoxyaniline.

In the title compound, C(17)H(19)NO(3), the mol-ecule has an E configuration with respect to the C=N bond and the dihedral angle between the aromatic rings is 56.07 (5)°. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds occur.

(E)-4-Bromo-N-(2,3-dimeth-oxy-benzyl-idene)aniline.

The title Schiff base compound, C(15)H(14)BrNO(2), was prepared by the condensation of 2,3-dimeth-oxy-benzaldehyde with 4-bromo-aniline. It adopts an E configuration with respect to the C=N bond. The dihedral angle between the two aromatic rings is 56.

(E)-4-Bromo-N-(2,3,4-trimeth-oxy-benzyl-idene)aniline.

The title Schiff base compound, C(16)H(16)BrNO(3), adopts an E configuration with respect to the C=N bond. The dihedral angle between the two aromatic rings is 64.02 (6)°.

N,N'-Bis(3,4-dimethoxy-benzyl-idene)butane-1,4-diamine.

The title Schiff base compound, C(22)H(28)N(2)O(4), was synthesized by the reaction of 3,4-dimethoxy-benzaldehyde and 1,4-diamino-butane in methanol. The mol-ecule is located on a center of inversion with one half-mol-ecule in the asymmetric unit. Both C=N double bonds are in a trans configuration.

Bis[4-(2-benzyl-idenepropyl-idene-amino)phen-yl] ether.

The title compound, C(32)H(28)N(2)O, is a flexible Schiff base displaying a trans configuration across the C=N double bond. It was prepared in high yield by condensation of α-methyl-cinnamaldehyde and bis-(4-amino-phen-yl) ether in methanol at room temperature. The sample, with pseudo-ortho-rhom-bic cell parameters, exhibited merohedral twinning by rotation 180° around a*, with a refined twin domain fraction of 0.