Growth, spectral, and thermal characterization of semicarbazone of p-hydroxy acetophenone (SPHA)

A new organic nonlinear optical material semicarbazone of p-hydroxy acetophenone (SPHA) was synthesized. Good quality single crystal of SPHA was successfully grown by slow evaporation method at room temperature. The crystal system was identified and lattice dimensions were measured from the single crystal X-ray diffraction (XRD) analysis. The various planes of reflection were identified from the powder XRD pattern. The presence of functional groups was qualitatively found by Fourier transform infrared (FTIR) spectral analysis. The proton and carbon nuclear magnetic resonance (¹HNMR and ¹³CNMR) spectral studies confirmed the presence of hydrogen and carbon bonded network in the grown crystal. The UV?CVisible absorption spectrum was recorded to study the optical transmittance in the range from 200 to 800?nm. The thermal stability of compound was determined by thermogravimetric and differential thermal analysis (TG-DTA) traces. The existence of second harmonic generation (SHG) signal was observed using Nd:YAG laser with fundamental wavelength of 1064?nm.     

Growth, spectral, and thermal characterization of 2-hydroxy-3-methoxybenzaldehyde semicarbazone

2-Hydroxy-3-methoxybenzaldehyde semicarbazone (HMBS) has been synthesized from 2-hydroxy-3-methoxybenzaldehyde and semicarbazide hydrochloride using sodium acetate as catalyst. Good quality single crystals of HMBS were successfully grown by slow evaporation method at room temperature using a mixture of DMF and ethanol as solvent. Fourier transform infrared and Fourier transform Raman spectral studies have been performed to identify the functional groups. Single-crystal XRD study was conducted to obtain the crystal structure and lattice parameters. The grown crystal was subjected to ¹H- and ¹³C-NMR spectral studies in order to confirm its structure and purity. The compound crystallizes into a monoclinic P21/c space group. Intermolecular hydrogen-bonding interactions facilitate unit cell packing in the crystal lattice. The UV–Vis spectrum confirmed the transparency of the compound between the wavelengths 420 and 1,100 nm, which is a characteristic property of a nonlinear optical (NLO) material. The thermal decomposition of the compound under static air atmosphere was investigated by simultaneous TG–DTG at a heating rate of 10 °C min^?1. The NLO property of HMBS was confirmed from the second-harmonic generation by Kurtz–Perry powder test.     

Growth, structural, spectral, mechanical, thermal and dielectric characterization of phosphoric acid admixtured L-alanine (PLA) single crystals

Phosphoric acid admixtured L-alanine (PLA) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 18 mm×12 mm×8 mm have been obtained in 28 days. The grown crystals were colorless and transparent. The solubility of the grown samples has been found out at various temperatures. The lattice parameters of the grown crystals were determined by X-ray diffraction technique. The reflection planes of the sample were confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. Fourier transform infrared (FTIR) studies were used to confirm the presence of various functional groups in the crystals. UV-visible transmittance spectrum was recorded to study the optical transparency of grown crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate (KDP) has been made. The mechanical strength of the crystal was estimated by Vickers hardness test. The grown crystals were subjected to thermo gravimetric and differential thermal analysis (TG/DTA). The dielectric behavior of the sample was also studied.     

Crystal growth, spectral, optical, and thermal characterization of glycyl-l-alanine hydrochloride (GLAH) single crystal

A new semi-organic nonlinear optical material glycyl-l-alanine hydrochloride (GLAH) was grown successfully by slow evaporation solution growth method. The solubility of GLAH was estimated for a wide range of temperatures. Large size single crystal of size 15?×?9?×?6?mm³ was grown at room temperature. The grown crystal was subjected to single crystal X-ray diffraction study which confirms that the grown crystal is monoclinic in nature with the space group P2₁. The molecular weight of the title compound was estimated by mass spectrometry. Functional groups and the modes of vibrations were identified by FT-IR spectral analysis. The UV?Cvisible spectral study reveals that the percentage of optical transmission of the sample is very high in the entire visible and UV regions. The second harmonic generation of the crystal was confirmed by the Kurtz and Perry technique. The hardness of the sample was tested by microhardness test which shows that the grown crystal belongs to the soft category of materials. The thermal stability of the compound was studied by TG?CDTA analyses which indicate that the crystal is thermally stable up to 248.6?°C.     

Growth,spectral, and thermal characterization of the NLO crystal: semicarbazone of <Emphasis Type="SmallCaps">dl</Emphasis>-camphor (SDLC)

Semicarbazone of dl-camphor (SdlC) crystals were grown using methanol as a solvent by slow evaporation solution growth technique at room temperature. Formation of the product and the presence of various functional groups present in the grown crystal have been identified using FTIR spectra. Single crystal XRD study was conducted to obtain the crystal structure and lattice parameters. The grown crystal was subjected to ¹HNMR and ¹³CNMR spectral studies and TG-DTA in order to confirm its structure, purity, and stability, respectively. The optical transparency of the crystal was tested using UV–Vis–NIR spectroscopy. The nonlinear optical (NLO) property of the grown crystal was confirmed from the second harmonic generation (SHG) by Kurtz–Perry powder test.     

Synthesis,spectral characterization and crystal structure of copper(II) complexes of 2-hydroxyacetophenone-N(4)-phenyl semicarbazone

Six new copper(II) complexes of 2-hydroxyacetophenone-N(4)-phenyl semicarbazone have been synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is inferred from IR spectra. Based on EPR studies, the spin Hamiltonian and bonding parameters have been calculated. The g   values, calculated for all the complexes in frozen DMF, indicate the presence of the unpaired electron in the d_x2-y2${\text{d}}_{x^2-y^2}$ orbital. The metal–ligand bonding parameters evaluated showed strong in-plane σ and in-plane π-bonding. The structure of the compound, CuLphen has been resolved using single crystal X-ray diffraction studies. The crystal structure revealed a monoclinic lattice with space group symmetry P2₁/c. The compound adopts a distorted square pyramidal geometry with a N₂O₂ core as the base.     

Octahedral Co(II) and Ni(II) complexes of Schiff bases,semicarbazone and thiosemicarbazone,synthesis, biological,spectral, and thermal studies

A new series of cobalt(II) and nickel(II) complexes, [M(ligand)(H₂O)₂(Y)] (M = Co(II) or Ni(II); Y = Cl^?, Br^? or NO₃ ^?), containing the Schiff-base semicarbazone and thiosemicarbazone, HL¹ and HL², formed from 4-hydroxycoumarin-3-carbaldehyde have been synthesized. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, infrared, electronic spectra, magnetic susceptibility, and conductivity measurements. An octahedral geometry has been suggested for the complexes. The metal complexes were screened for their antifungal and antibacterial activities on different species of pathogenic fungi and bacteria and their biopotency has been discussed.     

Structural and thermal characterization of Fe(III) and Fe(II) complexes with tridentate ONO pyridoxal semicarbazone

In the scope of design and optimise the equipment for alcoholic distillate beverages production, a sufficient knowledge of physical properties and phase equilibria is necessary. In this paper we present the temperature dependence of excess molar volumes of the ternary system ethanol+water+1-propanol at the range 288.15–323.15 K and atmospheric pressure, due to the importance of the 1-propanol among the flavour compounds contained into this type of beverages. Derived properties were computed due to its importance in the study of specific molecular interactions.     

Growth and characterization of a new metal-organic nonlinear optical bis (thiourea) cadmium zinc chloride single crystals

A new semiorganic nonlinear optical bis (thiourea) cadmium zinc chloride (BTCZC) crystal has been synthesized. BTCZC single crystals were grown from aqueous solution by slow evaporation technique. The solubility of BTCZC has been determined for various temperatures. Single crystal X-ray diffraction (XRD) study has been carried out to identify the lattice parameters. Fourier transform infrared (FTIR) studies confirm the various functional groups present in the grown crystal. The transmission and absorption spectra of this crystal show that the lower cut off wavelength lies at 260nm. The thermal analyses confirmed that the crystal is stable upto 201 degrees C. The nonlinear optical (NLO) property of the grown crystal has been confirmed by Kurtz-powder second harmonic generation (SHG) test.     

Structural, thermal and optical characterization of an organic NLO material--benzaldehyde thiosemicarbazone monohydrate single crystals

Single crystals of the organic NLO material, benzaldehyde thiosemicarbazone (BTSC) monohydrate, were grown by slow evaporation method. Solubility of BTSC monohydrate was determined in ethanol at different temperatures. The grown crystals were characterized by single crystal X-ray diffraction analysis to determine the cell parameters and by FT-IR technique to study the presence of the functional groups. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. UV-vis-NIR spectrum shows excellent transmission in the region of 200-1100 nm. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearities of BTSC have been investigated by Z-scan technique with He-Ne laser radiation of wavelength 632.8 nm. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. Second harmonic generation efficiency of the powdered BTSC monohydrate was tested using Nd:YAG laser and it is found to be ～5.3 times that of potassium dihydrogen orthophosphate.     

Growth, optical, thermal, and conductivity behavior of nonlinear optical single crystals of CdHg(SCN)4(CH3OC2H5O)

In this study, organometallic nonlinear optical single crystal of Cadmium mercury thiocyanate glycol monomethyl ether was grown by slow evaporation technique at room temperature. The grown crystal was confirmed by single crystal XRD and FT-IR analysis. Optical and thermal properties of the sample were investigated by UV–Vis–NIR, TG–DTA and DSC technique. Using Tauc’s relation, the band gap of the crystal was estimated as 3.99 eV. The thermal studies confirm that the CMTG is thermally stable up to 105 °C. Photoluminescence and ac & dc conductivity measurements of the sample were also carried out and reported for the first time. The PL analysis confirms the suitability of the material for application in the blue–green region. The temperature dependences of ac & dc conductivities of CMTG were investigated, and the activation energies were found to be 0.098 and 0.045 eV, respectively. The SHG efficiency measurement confirms that the NLO efficiency of CMTG is nearly three times more efficient than urea.     

Growth, spectral studies, thermal and dielectric aspects of l-lysine doped triglycine sulpho phosphate (TGSP) crystals

Single crystals of ferroelectric material triglycine sulpho phosphate (TGSP) have been grown by slow evaporation method. The effect of l-lysine addition on the growth of TGSP crystal has been studied for various concentrations (5, 10 and 20 mol%). Unit cell parameters were determined from powder XRD analysis. Functional groups present in the grown crystal were confirmed from the vibrational frequencies of recorded FTIR and FT-Raman spectrum. The l-lysine doping into the crystal lattice has been qualitatively confirmed by spectral analysis. Thermogravimetric studies confirm that the lysine is incorporated into TGSP crystals. Dielectric studies reveal that the incorporation of lysine into TGSP enhances its dielectric strength.     

Growth and characterization of 2-amino-4-picolinium 4-aminobenzoate single crystals

The organic material of 2-amino-4-picolinium 4-aminobenzoate (C₆H₉N₂⁺·C₇H₆NO₂^?) was synthesized and grown as single crystals at room temperature by slow evaporation solution growth technique in the constant temperature bath (±0.01 °C) using ethanol as solvent. The grown crystals were characterized by XRD and FT-IR spectral analyses. The melting point, density, UV–visible spectral studies were carried out for the grown crystals. The theoretical factor group analysis predicts 372 internal modes of vibration and optical modes in the grown title compound. The second harmonic generation (SHG) output of 2-amino-4-picolinium 4-aminobenzoate was recorded by Kurtz–Perry powder technique and it is found to be 355 mV at a given pulse energy of 1.45 mJ/s and for urea the SHG output was 525 mV. The dielectric behaviour of 2-amino-4-picolinium 4-aminobenzoate was investigated with different frequencies and temperatures.     

Growth and studies of thiourea urea magnesium chloride (TUMC) single crystals

A new semi organic Non-linear optical (NLO) crystal thiourea urea magnesium chloride (TUMC) was grown by slow evaporation technique at room temperature. Good quality single crystals were grown within 20?days. The FTIR spectrum of title compound was recorded and vibrational assignments were made. The recorded UV?Cvis spectrum shows the optical transmission property of the crystal. The Second harmonic generation (SHG) of TUMC crystal was tested by Kurtz?CPerry method using Nd:YAG laser and the result confirms that the grown crystal exhibits NLO property. To analyse the thermal stability of the crystal TG/DTA analysis were made. Detailed structural analysis of the compound is under progress.     

New fac-tricarbonyl rhenium(I) semicarbazone complexes: synthesis,characterization, and biological evaluation

Expanding our previous work on salicylaldehyde semicarbazone metal complexes as prospective anti-trypanosomal agents, five new fac-Re^I(CO)₃-containing complexes with ligands of this semicarbazone series were synthesized and characterized. An atypical coordination mode of these potentially tridentate ligands through only the carbonylic oxygen and the azomethine nitrogen (the so-called N,O fashion) was demonstrated by IR spectroscopy and supported by theoretical calculations. Three of the compounds showed moderate in vitro anti-Trypanosoma cruzi activity and increased activity with respect to the corresponding free ligands. The brominated ligands, 5-bromo-2-hydroxybenzaldehyde semicarbazone (L2) and 5-bromo-2-hydroxy-3-methoxybenzaldehyde semicarbazone (L5), led to the most active rhenium(I) complexes. These compounds are among the few reported examples of rhenium complexes bearing in vitro activity against T. cruzi.     

Aluminium-doped LiFePO4 single crystals. Part I. Growth, characterization and total conductivity

Single crystals of Al-doped LiFePO4 (1% Al) were grown by an optical floating zone technique. After cleaving from the as-grown ingot they exhibited a blackish-green color. The grown crystals have been characterized by the Laue X-ray technique, single-crystal and powder X-ray diffraction. Phase composition has been determined by chemical analysis to be Li0.985+/-0.009Fe0.984+/-0.12Al0.0126PO3.993+/-0.06. Secondary ion beam spectroscopy (SIMS) indicates a homogeneous distribution of doped Al in the single crystal block. The total conductivities are shown to be electronic conductivities and have been measured along different directions with the help of the cell Ti/LiFe(Al)PO4/Ti. The samples exhibit effectively two-dimensional electronic conductivities along b- and c-directions similar as in pure LiFePO4. This decrease of conductivity on Al-doping compared with undoped crystals is in agreement with our previous conclusion of p-type conductivity of LiFePO4. Unlike nominally pure material not only the association of holes with lithium vacancies plays an important role but also purely ionic association.     

Atomic-scale characterization of graphene grown on copper (100) single crystals

Growth of graphene on copper (100) single crystals by chemical vapor deposition has been accomplished. The atomic structure of the graphene overlayer was studied using scanning tunneling microscopy. A detailed analysis of moire? superstructures present in the graphene topography reveals that growth occurs in a variety of orientations over the square atomic lattice of the copper surface. Transmission electron microscopy was used to elucidate the crystallinity of the grown graphene. Pristine, defect-free graphene was observed over copper steps, corners, and screw dislocations. Distinct protrusions, known as "flower" structures, were observed on flat terraces, which are attributed to carbon structures that depart from the characteristic honeycomb lattice. Continuous graphene growth also occurs over copper adatoms and atomic vacancies present at the single-crystal surface. The copper atom mobility within vacancy islands covered with suspended graphene sheets reveals a weak graphene-substrate interaction. The observed continuity and room-temperature vacancy motion indicates that copper mobility likely plays a significant role in the mechanism of sheet extension on copper substrates. Lastly, these results suggest that the quality of graphene grown on copper substrates is ultimately limited by nucleation at the surface of the metal catalyst.     

Studies on the growth, optical, electrical and spectral properties of potassium pentaborate (KB5) single crystals

The bulk single crystals of nonlinear optical material potassium pentaborate (KB5) have been grown by slow evaporation solution growth technique using water as solvent. The grown crystal was confirmed by single crystal X-ray diffraction studies. The structural perfection of the grown crystals has been analyzed by high resolution X-ray diffraction (HRXRD) studies by recording rocking curve. The photoluminescence (PL), UV-vis spectral studies were performed and the optical bandgap of the material was calculated. FTIR and FT-Raman measurements enumerate the functional groups present in the compound. The factor group analysis on KB5 reveals that there are 117 vibrational optical modes. The dielectric behavior of KB5 was investigated with different frequencies and temperatures.     

Growth and characterization of naphthalene single crystals grown by modified vertical Bridgman method

The large size 20 mm diameter naphthalene single crystals were grown by modified vertical Bridgman method. The optical quality of the grown crystal was analyzed by photoluminescence and ultraviolet visible absorption spectral measurements. Photoluminescence spectrum indicated violet emission at 410 nm. The UV–vis absorption spectrum shows the maximum at 219.32 nm. The microhardness measurements and differential thermal analysis performed to analyze the mechanical and thermal stability of the as grown crystals. The dielectric measurements were carried out at five frequencies, viz., 100 Hz, 1 kHz, 10 kHz, 100 kHz and 1 MHz and at various temperatures, ranging from 308 K to 348 K indicate an increase of the dielectric parameters with the increase of temperature at all the five frequencies. The conductivity of the material is understood to be more of electronic in nature. Also, the increase in the dielectric parameters with that of temperature is due to the temperature variation of electronic polarizability.