(E)-N,N-Diethyl-4-{[(4-meth-oxy-phen-yl)imino]-meth-yl}aniline: crystal structure, Hirshfeld surface analysis and energy framework.

In the title benzyl-ideneaniline Schiff base, C18H22N2O, the aromatic rings are inclined to each other by 46.01 (6)°, while the Car-N= C-Car torsion angle is 176.9 (1)°. In the crystal, the only identifiable directional inter-action is a weak C-H⋯π hydrogen bond, which generates inversion dimers that stack along the a-axis direction.

Syntheses, crystal structures, Hirshfeld surface analyses and energy frameworks of two 4-amino-anti-pyrine Schiff base compounds: (E)-4-{[4-(di-ethyl-amino)-benzyl-idene]amino}-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one and (E)-4-[(4-fluoro-benzyl-idene)amino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one.

The title Schiff base compounds, C22H26N4O (I) and C18H16FN3O (II), were each synthesized by a single-step condensation reaction. The substituted benzyl-idene ring is inclined to the pyrazole ring mean planes by 22.92 (7)° in I and 12.70 (9)° in II. The phenyl ring of the 4-amino-anti-pyrine unit is inclined to the pyrazole ring mean plane by 54.87 (7)° in I and by 60.44 (8)° in II. In the crystal of I, the mol-ecules are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions to form layers lying parallel to (001). In the crystal of II, the mol-ecules are linked by C-H⋯O and C-H⋯F hydrogen bonds and C-H⋯π inter-actions, thereby forming layers lying parallel to (010). Hirshfeld surface analysis was employed to further qu-antify the inter-atomic inter-actions in the crystals of both compounds.

Synthesis, crystal structure and Hirshfeld surface analysis of the ortho-rhom-bic polymorph of 4-bromo-N-(4-bromo-benzyl-idene)aniline.

The crystal structure of the title compound, C13H9Br2N [systematic name: (E)-N,1-bis-(4-bromo-phen-yl)methanimine], is a second polymorph (Form II) crystallizing in the ortho-rhom-bic space group Pccn. The first polymorph (Form I) crystallizes in the monoclinic space group P21/c [Bernstein & Izak (1975 ▸). J. Cryst. Mol. Struct. 5, 257-266; Marin et al. (2013 ▸). J. Mol. Struct. 1049, 377-385]. The mol-ecule is disordered about an inversion center situated in the middle of the C=N bond, similar to the situation in the monoclinic polymorph: the C=N bond length is 1.243 (7) Å. In the crystal, mol-ecules stack along the b-axis direction and are linked by C-H⋯π inter-actions. The inter-atomic contacts in the crystal for both polymorphs were studied by Hirshfeld surface analysis and have notable differences. The solid-state fluorescence spectrum of Form II shows an emission peak at ca 469 nm. The two-photon absorption coefficient measured from the open aperture Z-scan technique is 1.3 × 10 -11 m W-1, hence, Form II shows optical limiting behaviour.

Effect of α-Fe2O3 Phase on the Magnetic Interactions in Nickel Ferrite (NiFe2O4) Nanoparticles.

We report on the effect of α-Fe2O3 phase in the magnetic properties and magnetic interactions in nickel ferrite (NiFe2O4-NFO) nanoparticles synthesized by co-precipitation method. Structural analysis confirms the formation of the cubic inverse spinel phase without any impurities for the NFO sample annealed in air at 650 °C. When the annealing temperature is increased to 750 °C and 850 °C, α-Fe2O3 impurity phase is formed along with the parent NFO phase. Raman spectra recorded at room temperature (RT) confirm the presence of pure NFO phase for the sample annealed at 650 °C, and presence of α-Fe2O3 phase is observed in the samples annealed at 750 °C and 850 °C. Saturation magnetization values at RT for the NFO samples annealed at 650 °C, 750 °C and 850 °C are 34 emu/g, 19 emu/g and 28 emu/g respectively. Zero Field Cooled (ZFC) and Field Cooled (FC) measurement reveals the super-paramagnetic behavior along with competing magnetic interactions in all the samples. For the NFO sample annealed at 750 °C and 850 °C, a drop in ZFC magnetization and a small kink in FC magnetization observed around 245 K indicate the presence of a Morin transition (TM) from the α-Fe2O3 phase. Anisotropy constants were calculated for all the samples using the law of approach to saturation (LAS) method. The magnetocrystalline anisotropy energy distribution function for the NFO samples annealed at 750 °C and 850 °C exhibit broad peak due to the random distribution of spins associated with different particle size.

Role of annealing on the structural and optical properties of nanostructured diaceto bis-benzimidazole Mn(II) complex thin films.

A coordination complex, manganese incorporated benzimidazole, thin films were prepared by chemical bath deposition method. Structural characterization of the deposited films, carried out by Fourier transform infrared spectroscopy, Raman and electron paramagnetic resonance spectral analyses, reveals the distorted tetrahedral environment of the metal ion with bis-benzimidazole ligand. Further the molecular composition of the deposited metal complex was estimated by energy-dispersive X-ray spectroscopy. The prepared thin films were thermally treated to study the effect of annealing temperature on the surface morphology and the results showed that the surface homogeneity of the films increased for thermally treated films up to 150°C. But distortion and voids were observed for the films annealed at 200°C. The Raman analysis reveals the molecular hydrogen bond distortion which leads to the evaporation of the metal complex from the thin film surface with respect to annealing temperature. The linear and nonlinear optical properties of the as prepared and annealed films were studied using ultraviolet-visible transmittance spectroscopy, second harmonic generation and Z-scan analyses. Films annealed at 150°C show a better linear transmittance in the visible region and larger SHG efficiency and third order nonlinear susceptibility when compared with the other samples. Further, the film annealed at 150°C was subjected to optical switching analysis and demonstrated to have an inverted switching behavior.

Spectral, morphological, linear and nonlinear optical properties of nanostructured benzimidazole metal complex thin films.

Metal organic materials are widely investigated to find their suitability for nonlinear optical applications due to the advantage of combined organic and inorganic properties. In this work benzimidazole based metal organic thin films of dichlorobis (1H-Benzimidazole) Co(II) and dichlorobis (1H-Benzimidazole) Cu(II) were deposited by chemical bath deposition method. The deposited films were annealed at 100, 150 and 200 °C to investigate the effect of annealing on the properties of thin films. Surface homogeneity of the films was increased with the annealing temperature due to the surface diffusion of the films and the same was evidently shown by Raman spectroscopy and Atomic Force Microscopy studies. But annealing the films at 200 °C yielded bulk patches on the surface due to the distortion of molecules. Linear and nonlinear optical properties of the films annealed at 150 °C showed relatively higher transmittance and improved nonlinear optical properties than the other as prepared and annealed samples.

Crystal structure of catena-poly[[cadmium(II)-di-µ2-bromido-µ2-l-proline-κ(2) O:O'] monohydrate].

In the title coordination polymer, {[CdBr2(C5H9NO2)]·H2O} n , the Cd(II) ion is coordinated by four bromido ligands and two carboxyl-ate oxygen atoms of two symmetry-related proline ligands, which exist in a zwitterionic form, in a distorted octa-hedral geometry. There is an intra-molecular N-H⋯O hydrogen bond between the amino group and the carboxyl-ate fragment. Each coordinating ligand bridges two Cd(II) atoms, thus forming polymeric chains running along the c-axis direction. The water mol-ecules of crystallization serve as donors for the weak inter-molecular O-H⋯O and O-H⋯Br hydrogen bonds that link adjacent polymeric chains, thus forming a three-dimensional structure. N-H⋯O and N-H⋯Br hydrogen bonds also occur.

Growth, spectral, thermal, optical, mechanical and etching studies of l-lysine semi-maleate (l-LSM) single crystals.

Organic nonlinear optical material, l-lysine semi-maleate (l-LSM) single crystals were grown by slow cooling solution growth technique. The crystal system of grown l-LSM was confirmed by single crystal and powder X-ray diffraction analyzes. Functional groups of the grown crystal have been identified by Fourier Transform Infrared spectral analysis. The proton and carbon NMR spectral studies confirm the presence of hydrogen and carbon in the grown l-LSM. The melting and thermal decomposition temperatures of the crystal were determined using thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses. Optical transparency, second harmonic generation efficiency, micro hardness, dielectric constant and loss, refractive index and birefringence have also been measured. Further, the growth patterns and dislocations present in the grown crystal are studied.

Synthesis, structure, crystal growth and characterization of a novel semiorganic nonlinear optical l-proline lithium bromide monohydrate single crystal.

l-Proline lithium bromide monohydrate (LPLBM), a promising semiorganic nonlinear optical material, was synthesized and single crystals of LPLBM were grown from solution by slow evaporation technique. Single crystal X-ray structure solution reveals that the grown crystal belongs to monoclinic system with space group P21. Presence of various functional groups was identified by FT-IR and FT-Raman spectral analyses. UV-Vis-NIR spectroscopic study shows that the LPLBM crystal possesses 90% of transmittance in the range of 250-1100nm. Vickers microhardness values, the dielectric constant and dielectric loss of the LPLBM crystal were reported. Elemental analysis by energy dispersive X-ray analysis shows the presence of carbon, nitrogen, oxygen and bromine. The surface morphology of the crystal was investigated using scanning electron microscopic study. The thermal stability of the LPLBM crystal was studied from TGA and DSC analysis. Second harmonic generation efficiency of the LPLBM crystal measured by Kurtz and Perry powder technique using Nd:YAG laser is about 0.3 times that of urea.

Structural, optical, mechanical and dielectric studies of pure and doped L-Prolinium trichloroacetate single crystals.

In the present work, pure and metal substituted L-Prolinium trichloroacetate (LPTCA) single crystals were grown by slow evaporation method. The grown crystals were subjected to single crystal X-ray diffraction (XRD), powder X-ray diffraction, FTIR, UV-Visible-NIR, hardness, photoluminescence and dielectric studies. The dopant concentration in the crystals was measured by inductively coupled plasma (ICP) analysis. Single crystal X-ray diffraction studies of the pure and metal substituted LPTCA revealed that the grown crystals belong to the trigonal system. Ni(2+) and Co(2+) doping slightly altered the lattice parameters of LPTCA without affecting the basic structure of the crystal. FTIR spectral analysis confirms the presence of various functional groups in the grown crystals. The mechanical behavior of pure and doped crystals was analyzed by Vickers's microhardness test. The optical transmittance, dielectric and photoluminescence properties of the pure and doped crystals were analyzed.

4-Fluoro-N-(4-hy-droxy-benzyl-idene)aniline.

In the title compound, C13H10FNO, the benzene ring planes are inclined at an angle of 50.52 (8)°. A characteristic of aromatic Schiff bases with N-aryl substituents is that the terminal phenyl rings are twisted relative to the plane of the HC=N link between them. In this case, the HC=N unit makes dihedral angles of 10.6 (2) and 40.5 (2)° with the hy-droxy-benzene and fluro-benzene rings, respectively. In the crystal, O-H⋯N and C-H⋯F hydrogen bonds lead to the formation of chains along the c- and b-axis directions, respectively. C-H⋯π contacts link mol-ecules along a and these contacts combine to generate a three-dimensional network with mol-ecules stacked along the b-axis direction.

1-(2-Chloro-phen-yl)-3-(2-ethyl-hexa-noyl)thio-urea.

In the title compound, C15H21ClN2OS, the central chromophore moiety (C2N2OS) is approximately planar, with a maximum deviation of -0.027 (1) Å, and is oriented at a dihedral angle of 86.7 (1)° with respect to the chloro-phenyl ring. An intra-molecular N-H⋯O hydrogen bond stabilizes the mol-ecular conformation. In the crystal, mol-ecules associate via N-H⋯S hydrogen bonds, forming inversion dimers with motif R 2 (2)(8). These dimers are further connected by N-H⋯O hydrogen bonds, forming R 2 (2)(12) dimers. As a result, hydrogen-bonded chains running along [110] are formed. C-H⋯S inter-actions also occur. The terminal two C atoms of the butyl chain are disordered over two positions with an occupancy ratio of 0.54:0.46.

Design and fabrication of eight zone vertical dynamic gradient freeze system for organic single crystal growth.

Design and construction of the vertical dynamic gradient freeze (VDGF) system operating in the temperature range from 50 °C to 500 °C for growing organic single crystals are described. The design of VDGF system consists of furnace, control system, translation assembly, and image capturing device. Furnace has been constructed with eight zones controlled independently by a dynamic temperature control system for achieving desired thermal environment and multiple temperature gradients, which are essential for the growth of organic single crystals. The transparent furnace enables direct observation to record and monitor the solid-liquid interface and growth of crystals through charge coupled device based video camera. The system is fully computerized hence it is possible to retrieve the complete growth and furnace history. In order to investigate the functioning of the constructed VDGF system for the growth of organic single crystals, a well known organic nonlinear optical single crystal of benzimidazole was grown. The crystalline quality and the optical transmittance of the grown crystal were studied.

catena-Poly[[[aqua-(glycine-κO)lithium]-µ-glycine-κ(2) O:O'] bromide].

In the title coordination polymer, {[Li(C2H5NO2)2(H2O)]Br} n , the Li(+) cation is coordinated by three carboxyl-ate O atoms of zwitterionic glycine mol-ecules and by a water mol-ecule, forming a distorted tetra-hedral geometry. One of the two glycine mol-ecules bridges neighbouring complexes, forming an infinite chain parallel to the c axis. Polymeric chains are further linked by extensive hydrogen bonds involving the Br(-) anions and glycine and water mol-ecules, producing a three-dimensional network.

Glycine-phthalic acid (1/1).

In the title compound, C2H5NO2·C8H6O4, the glycine mol-ecule exists as a zwitterion (2-aza-niumyl-ethano-ate) with a positively charged amino group and a negatively charged carboxyl-ate group. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the components into layers parallel to the ab plane. The central part of each layer is composed of hydrogen-bonded glycine zwitterions, while phthalic acid mol-ecules inter-act with the zwitterions in such a way that benzene rings protrude up and down from the layer.

Synthesis, growth, crystalline perfection of 4-bromo-4'dimethylamino benzylideneaniline (BDMABA) and photons absorption of BDMABA crystal.

One of the Schiff base 4-bromo-4'dimethylamino benzylideneaniline (BDMABA) compounds was synthesized and single crystal of the material was grown by solvent evaporation method at room temperature. Molecular structure of BDMABA was confirmed by (1)H nuclear magnetic resonance and the presence of functional groups was confirmed by Fourier Transform Infrared and Fourier Transform Raman spectral analyses. Cell parameters were determined using single crystal X-ray diffraction analysis and crystalline perfection of the grown BDMABA crystal was evaluated using high-resolution X-ray diffraction analysis. Thermal analyses indicated that the material is thermally stable up to 215 °C and its melting point is 161.5 °C. Vickers microhardness study was carried out to estimate the mechanical hardness of BDMABA crystal which shows that the crystal belongs to the class of soft materials. Linear and nonlinear optical studies were carried out using UV-vis-NIR spectrum and open aperture Z-scan technique respectively.

Synthesis, growth and characterization of L-lysinium(+)...L-lysinium(2+) dichloride perchlorate (LLDP) single crystals by Sankaranarayanan-Ramasamy method.

L-lysinium(+)...L-lysinium(2+) dichloride perchlorate was synthesized at ambient temperature and bulk single crystals were grown by conventional and Sankaranarayanan-Ramasamy methods. Crystals grown by these methods were subjected to single crystal X-ray diffraction, Fourier transform infrared, high resolution X-ray diffraction, Vickers microhardness and thermogravimetric/differential scanning calorimetric/differential thermal analyses. Further, the cut-off wavelength and optical transmittance of the grown crystals were determined by UV-vis-NIR spectrum. Linear refractive index (n(x)) of the crystal was measured using minimum deviation method for different wavelengths. Optical quality of the grown crystals was analyzed by conoscopic interference pattern and the birefringence was calculated using interferometric technique. Surface laser damage threshold of the crystal was determined using Nd:YAG laser. The nonlinear refractive index n(2) was measured through the Z-scan technique using low power continuous wave HeNe laser. Frequency and temperature dependent dielectric constant (ε(r)) and dielectric loss (tanδ) were measured.

Growth and spectral characterization of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate - a semi organic NLO material.

Semi-organic non-linear optical single crystals of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate crystals were grown by slow evaporation solution growth technique, at room temperature, using de-ionized water as solvent. The modes of vibrations of different molecular groups present in the grown crystal were identified by FT-IR technique. The optical absorbance/transmittance was recorded in the wavelength range of 190-1100 nm. Thermal properties of the grown crystal were studied by thermo gravimetric analysis and differential thermal analysis. The melting point of the grown crystal was estimated by differential scanning calorimetric analysis. The inclusion of the dopant (EDTA) was confirmed by colorimetric estimation method. The second harmonic generation efficiency is about 30% of potassium dihydrogen orthophosphate.

Investigations on growth and crystalline perfection of an organic Schiff base material: 4-chloro-4'bromobenzylidene aniline.

Single crystal of an organic material, 4-chloro-4'bromobenzylidene aniline (CBBA), was synthesized and grown by slow evaporation method at room temperature. (1)H and (13)C NMR spectra were recorded to elucidate the molecular structure and functional groups of CBBA were identified using FTIR and FT Raman spectral analyses. The lattice parameters were calculated from single crystal X-ray diffraction data. Single and reasonably sharp peak observed in the high resolution X-ray diffraction curve indicates that the quality of the crystal is good. Thermal properties of CBBA were carried out using thermogravimetric, differential thermal and differential scanning calorimetric analyses and the melting point of the CBBA material is ~123 °C. The dielectric properties of CBBA crystal was studied as the function of frequency (100 Hz-500 kHz). The optical properties were ascertained by recording UV-vis-NIR and fluorescence spectrum. Further the mechanical properties were studied using Vickers microhardness test.

4-Bromo-N-(4-hy-droxy-benzyl-idene)-aniline.

In the title compound, C(13)H(10)BrNO, the benzene ring planes are inclined at an angle of 48.85 (17)°, resulting in a nonplanar mol-ecule. A characteristic of aromatic Schiff bases with N-aryl substituents is that the terminal phenyl rings are twisted relative to the HC=N plane. In this case, the HC=N unit makes dihedral angles of 11.1 (4) and 38.5 (3)° with the hy-droxy-benzene and bromo-benzene rings, respectively. In the crystal, the molecules are linked by O-H⋯N hydrogen bonds to form infinite (C8) chains along the b axis.