Crystal structure and DFT computational studies of (E)-2,4-di-tert-butyl-6-{[3-(tri-fluoro-meth-yl)benz-yl]imino-meth-yl}phenol.

The title compound, C23H28F3NO, is an ortho-hy-droxy Schiff base compound, which adopts the enol-imine tautomeric form in the solid state. The mol-ecular structure is not planar and the dihedral angle between the planes of the aromatic rings is 85.52 (10)°. The tri-fluoro-methyl group shows rotational disorder over two sites, with occupancies of 0.798 (6) and 0.202 (6). An intra-molecular O-H⋯N hydrogen bonding generates an S(6) ring motif. The crystal structure is consolidated by C-H⋯π inter-actions. The mol-ecular structure was optimized via density functional theory (DFT) methods with the B3LYP functional and LanL2DZ basis set. The theoretical structure is in good agreement with the experimental data. The frontier orbitals and mol-ecular electrostatic potential map were also examined by DFT computations.

Crystal structure and Hirshfeld surface analysis of (E)-2,4-di-tert-butyl-6-[(3-chloro-4-methyl-phenyl-imino)-meth-yl]phenol.

The title Schiff base compound, C22H28ClNO, shows mirror symmetry with all its non-H atoms, except the tert-butyl groups, located on the mirror plane. There is an intra-molecular O-H⋯N hydrogen bond present forming an S(6) ring motif. In the crystal, the mol-ecules are connected by C-H⋯π inter-actions, generating a three-dimensional supra-molecular structure. Hirshfeld surface analysis and two dimensional fingerprint plots were used to analyse the inter-molecular inter-actions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (68.9%) and C⋯H/H⋯C (11.7%) inter-actions.

Erratum: Crystal structure and Hirshfeld surface analysis of (E)-N-[(2-eth-oxy-naphthalen-1-yl)methyl-idene]-5,6,7,8-tetra-hydro-naphthalen-1-amine. Corrigendum.

[This corrects the article DOI: 10.1107/S2056989018013117.].

Crystal structure and Hirshfeld surface analysis of (E)-N-[(2-eth-oxy-naphthalen-1-yl)methyl-idene]-5,6,7,8-tetra-hydro-naphthalen-1-amine.

In the title Schiff base compound, C23H23NO, the two ring systems are twisted by 51.40 (11)° relative to each other. In the crystal, the mol-ecules are connected by weak C-H⋯π inter-actions, generating a three-dimensional supra-molecular structure. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (67.2%), C⋯H/H⋯C (26.7%) and C⋯C (2.5%) inter-actions.

Crystal structure, spectroscopic characterization and density functional studies of (E)-1-((3-methoxyphenylimino)methyl)naphthalen-2-ol.

The Schiff base compound (E)-1-((3-methoxyphenylimino)methyl)naphthalen-2-ol was synthesized from the reaction of 2-hydroxy-1-naphthaldehyde with 3-methoxyaniline. The structural properties of the compound has been characterized by using FT-IR, UV-vis and X-ray single-crystal methods. According to X-ray diffraction result, the title compound exists in the phenol-imine tautomeric form. The molecular geometry, vibrational frequencies of the compound in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set, and compared with the experimental data. The obtained results show that the optimized molecular geometry is well reproduce the crystal structure. The theoretical vibrational frequencies are in good agreement with the experimental values. The calculations of electronic absorption spectra of tautomeric forms of the compound were performed by using TD-DFT calculations both in the gas phase and ethanol solvent. To investigate the tautomeric stability, optimization calculations at the B3LYP/6-311++G(d,p) level were performed for the phenol-imine and keto-amine forms of the compound. According to calculated results, the OH form is more stable than NH form. In addition, molecular electrostatic potential (MEP), frontier molecular orbital analysis (HOMO-LUMO), thermodynamic and, non-linear optical (NLO) properties of the compound were investigated using same theoretical calculations.

An experimental and theoretical study on the novel (Z)-1-((naphthalen-2-ylamino)methylene)naphthalen-2(1H)-one crystal.

A novel compound has been synthesized, and its structure has been characterized by IR, UV-vis, NMR and X-ray single-crystal determination techniques. The title compound crystallizes in the orthorhombic space group P212121 with a=6.2120(4)Å, b=10.8242(7)Å, c=22.3857(15)Å and Z=4. The crystal structure has intramolecular N-H···O hydrogen bond and C-H···Cg interaction. These hydrogen bonds and interactions are effective in crystal packing. The optimum molecular geometry, conformational analysis, normal mode wavenumbers, infrared and Raman intensities, corresponding vibrational assignments, chemical shift assignments, and thermo-dynamical parameters have been investigated with the help of Density Functional Theory (DFT). Detailed vibrational assignments have been made on the basis of potential energy distribution (PED). In order to understand the electronic transitions of the compound, time dependent DFT (TD-DFT) calculations were performed in gas phase. Also, the dipole moment, linear polarizabilities, anisotropy and first hyperpolarizabilities values have been computed.

1-{(E)-[4-Bromo-2-(trifluoro-meth-oxy)phen-yl]imino-meth-yl}naphthalen-2-ol.

The title compound, C18H11BrF3NO2, crystallizes in the phenol-imine tautomeric form, with a strong intra-molecular O-H⋯N hydrogen bond. The dihedral angle between the naphthalene ring system and the benzene ring is 28.54 (10)°.

(E)-(2,5-Difluoro-benz-yl)[(2-eth-oxy-naphthalen-1-yl)methyl-idene]amine.

In the title mol-ecule, C20H17F2NO, which adopts an E conformation with respect to the imine C=N double bond, the mean planes of the naphthalene ring system and the difluoro-phenyl ring form a dihedral angle of 85.82 (7)°. An intra-molecular C-H⋯N hydrogen bond occurs. In the crystal, weak C-H⋯F hydrogen bonds link the mol-ecules into zigzag chains along [010].

4-Meth-oxy-2-{(E)-[(thio-phen-2-yl)methyl-imino]-meth-yl}phenol.

The title Schiff base, C(13)H(13)NO(2)S, adopts the phenol-imine tautomeric form and reveals an intra-molecular O-H⋯N hydrogen bond involving the hy-droxy group and the imino N atom, forming an S(6) ring. The mol-ecule is highly twisted with respect to the central imine group, which is reflected in the dihedral angle of 67.83 (10)° formed by the thienyl and phenol rings. The crystal packing is characterized by weak C-H⋯O and C-H⋯π inter-actions.

(E)-3-Chloro-N-[(2-eth-oxy-naphthalen-1-yl)methyl-idene]aniline.

In the title compound, C(19)H(16)ClNO, the dihedral angle between the naphthalene ring system and the chloro-benzene ring is 61.90 (10)° and the C-N-C-C torsion angle is 174.6 (2)°. The mol-ecular structure is stabilized by an intra-molecular C-H⋯N hydrogen bond. The crystal structure features π-π stacking inter-actions [centroid-centroid distances = 3.7325 (17) and 3.8150 (17) Å].

(E)-N-[(2-Eth-oxy-naphthalen-1-yl)methyl-idene]-2-ethyl-aniline.

In the title compound, C(21)H(21)NO, the dihedral angle between the naphthalene ring system and the benzene ring is 64.61 (6)°. The mol-ecular structure is stabilized by an intra-molecular C-H⋯N hydrogen bond.

(E)-1-{2-Hy-droxy-5-[(4-methyl-phen-yl)diazen-yl]phen-yl}ethanone.

The structure of the title compound, C(15)H(14)N(2)O(2), an azo dye, displays a trans configuration with respect to the N=N bridge. The dihedral angle between the aromatic rings is 5.06 (8)°. The mol-ecular conformation is stabilized by a strong intra-molecular O-H⋯O hydrogen bond. In the crystal, inter-molecular C-H⋯O hydrogen bonds occur.

Solid phase extraction and preconcentration of Cu(II), Pb(II), and Ni(II) in environmental samples on chemically modified Amberlite XAD-4 with a proper Schiff base.

A new chelating resin, Amberlite XAD-4 loaded with N,N-bis(salicylidene)cyclohexanediamine (SCHD), was synthesized and characterized. The resin Amberlite XAD-4-SCHD was used for selective separation, preconcentration, and determination of Cu(II), Pb(II), and Ni(II) ions in water samples by flame atomic absorption spectrometry (FAAS). Effects of pH, concentration, and volume of elution solution; flow rate of elution; and sample solution, sample volume, and interfering ions for the recovery of the analytes were investigated. These metal ions can be desorbed with 0.5-M HNO3 (recovery, 98%-101%). The sorption capacity was found between 1.38×10(-1) and 3.58×10(-1) mmol/g. In order to evaluate the accuracy of the proposed procedure, the certified reference materials, BCR-032 (Moroccan phosphate rock) and BCR-715 (industrial effluent wastewater), were analyzed. The detection limits of the method were found to be 0.11, 1.91, and 0.43 µg/L for Cu(II), Pb(II), and Ni(II), respectively. The method was applied to the extraction and the recovery of copper, lead, and nickel in wastewater and other water samples.

(E)-1-[(2-Fluoro-phen-yl)imino-meth-yl]-2-naphthol-(Z)-1-[(2-fluoro-phen-yl)amino-methyl-idene]naphthalen-2(1H)-one (0.57/0.43).

The title Schiff base compound, 0.57C(17)H(12)FNO·0.43C(17)H(12)FNO, reveals both the enol (OH) and keto (NH) tautomeric forms with occupancies of 0.57 (6) and 0.43 (6), respectively. The tautomeric forms are stabilized by intra-molecular O-H⋯N (enol) and N-H⋯O (keto) hydrogen bonds. The dihedral angle between the naphthalene ring system and the benzene ring is 32.76 (1)°.

(E)-2-[(4-Iodo-phen-yl)imino-meth-yl]-6-methyl-phenol.

The title compound, C(14)H(12)INO, adopts the phenol-imine tautomeric form. The dihedral angle between the aromatic rings is 20.6 (3)°. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond while in the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a zigzag chain parallel to the b axis.

2-[(E)-2-(4-Methyl-benzene-sulfonamido)ethyl-iminiometh-yl]-4-nitro-phenolate.

The mol-ecule of the title compound, C(16)H(17)N(3)O(5)S, crystallizes in a zwitterionic form, with a strong intra-molecular N-H⋯O hydrogen bond. The dihedral angle between the two benzene rings is 7.06 (9)°. In the crystal, mol-ecules are linked into chains along the c axis by inter-molecular N-H⋯O hydrogen bonds.

2-[(4-Ethoxy-phen-yl)imino-meth-yl]-5-methoxy-phenol.

The title compound, C(16)H(17)NO(3), a Schiff base, is stabilized in the solid state in the phenol-imine tautomeric form, with the H atom located on the hydr-oxy O atom rather than on the N atom. This H atom is involved in a strong intra-molecular O-H⋯N hydrogen bond. The mol-ecule is almost planar, the angle between the benzene rings being 4.43 (13)°. C-H⋯π inter-actions are also present.

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

The title compound, C(14)H(9)ClF(3)NO(2), crystallizes in a phenol-imine tautomeric form, with a strong intra-molecular O-H⋯N hydrogen bond. The dihedral angle between the two benzene rings is 47.62 (9)°. In the crystal, mol-ecules are linked into chains along the c axis by C-H⋯O hydrogen bonds, and weak C-H⋯π inter-actions involving both benzene rings are also observed.

(E)-2-[3-(Trifluoro-meth-yl)phenyl-imino-meth-yl]benzene-1,4-diol.

In the title compound, C(14)H(10)F(3)NO(2), the two benzene rings are oriented at a dihedral angle of 31.94 (14)°. An intra-molecular O-H⋯N hydrogen bond helps to stabilize the mol-ecular structure. In the crystal, inter-molecular O-H⋯O hydrogen bonding links the mol-ecules, forming chains running along the crystallographic a axis. The F atoms of the trifluoro-methyl group are disordered over two positions with refined site occupancies of 0.488 (5) and 0.512 (5).

(E)-2-[(2,4-Dichloro-phen-yl)imino-meth-yl]benzene-1,4-diol monohydrate.

The title compound, C(13)H(9)Cl(2)NO(2)·H(2)O, represents a Schiff base which adopts the phenol-imine tautomeric form in the solid state. The mol-ecule is approximately planar (r.m.s. deviation 0.0818 Å), and the dihedral angle between the two aromatic rings is 7.46 (12)°. An O-H⋯N inter-action generates an S(6) ring. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds involving the solvent water mol-ecule, forming chains.