A series of glass samples with chemical formula {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Dy2O3)xwhere x=0.01, 0.02, 0.03, 0.04 and 0.05M fraction were synthesized through conventional melt-quenching method. The most common way to fabricate a glass material is by fusion of two or more component oxides followed by their quenching. This technique is known as melt-quenching technique. Kaur et al. (2016) [1] highlighted that the melt-quenching method able to enhance the mechanical properties like hardness and flexural strength of the material. The nature of the glass systems is proven to be amorphous based on the XRD pattern. The FTIR spectra of the glass systems confirm the existence of five bands which are assigned for the BO4, BO3,TeO4and TeO3vibrational groups. The density of the glass systems is increased with the addition of Dy2O3while the molar volume is found to be inversely proportional to the density of the proposed glass. The optical properties of the glasses are determined through the absorption spectra obtained from the UV-VIS spectrophotometer. From the absorption spectra, the indirect and direct optical band gaps and the Urbach energy are found to be inversely proportional to each other. As the molar fraction of the Dy2O3increased, the optical band gaps are observed to increase as opposed to the Urbach energy. For this glass system, the values of refractive index, electronic polarizability, oxide ion polarizability and the optical basicity are found to decrease as the addition of the dysprosium oxide is increased. From the emission spectra, two intense blue and yellow emission bands are observed, which correspond to the4F9/2→6H15/2and4F9/2→6H13/2transitions of Dy3+ions respectively. The CIE chromaticity coordinates of the zinc borotellurite glass systems are found to be located in the white light region.
The natural dyes anthocyanin and chlorophyll were extracted from Musa acuminata bracts and Alternanthera dentata leaves, respectively. The dyes were then applied as sensitizers in TiO2-based dye-sensitized solar cells (DSSCs). The ethanol extracts of the dyes had maximum absorbance. High dye yields were obtained under extraction temperatures of 70 to 80°C, and the optimal extraction temperature was approximately 80°C. Moreover, dye concentration sharply decreased under extraction temperatures that exceeded 80°C. High dye concentrations were obtained using acidic extraction solutions, particularly those with a pH value of 4. The DSSC fabricated with anthocyanin from M. acuminata bracts had a conversion efficiency of 0.31%, short-circuit current (Isc) of 0.9mA/cm2, open-circuit voltage (Voc) of 0.58V, and fill factor (FF) of 62.22%. The DSSC sensitized with chlorophyll from A. dentata leaves had a conversion efficiency of 0.13%, Isc of 0.4mA/cm-2,Voc of 0.54V, and FF of 67.5%. The DSSC sensitized with anthocyanin from M. acuminata bracts had a maximum incident photon-to-current conversion efficiency of 42%, which was higher than that of the DSSC sensitized with chlorophyll from A. dentata leaves (23%). Anthocyanin from M. acuminata bracts exhibited the best photosensitization effects.
A new thiosemicarbazone derivative, N-(2-hydroxyphenyl)-2-[1-(pyridin-4-yl)ethylidene]hydrazinecarbothioamide (HPEH), has been synthesized, characterized, and further developed as a highly selective and sensitive colorimetric chemosensor for Hg2+ recognition in environmental water samples. Structural conformers of HPEH were successfully identified using a combination of the potential energy surface (PES) and time-dependent density functional theory (TD-DFT) methods. The synthesized HPEH was successfully characterized further and analyzed based on its harmonic vibrational frequencies, NMR spectra, and electronic transitions using the DFT approach. Sigma profiles were generated using the COSMO-RS approach to identify a compatible medium for HPEH to act as a chemosensor. The conditions for the highly sensitive and selective detection of Hg2+ by HPEH were successfully optimized using the statistical response surface methodology approach. The optimum sensing of HPEH occurred in an 8:2 v/v DMSO/pH 7.8 solution at a 20:60 μM HPEH/Hg2+ concentration and after a reaction time of 18 min, with statistically significant independent variables (p
Surface plasmon resonance (SPR) is a label-free optical spectroscopy that is widely used for biomolecular interaction analysis. In this work, SPR was used to characterize the binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite (CTA-NCC/GO) towards nickel ion. The formation of CTA-NCC/GO nanocomposite has been confirmed by FT-IR. The SPR analysis result shows that the CTA-NCC/GO has high binding affinity towards Ni2+ from 0.01 until 0.1 ppm with binding affinity constant of 1.620 × 103 M-1. The sensitivity for the CTA-NCC/GO calculated was 1.509° ppm-1. The full width at half maximum (FWHM), data accuracy (DA), and signal-to-noise ratio (SNR) have also been determined using the obtained SPR curve. For the FWHM, the value was 2.25° at 0.01 until 0.08 ppm and decreases to 2.12° at 0.1 until 10 ppm. The DA for the SPR curves is the highest at 0.01 until 0.08 ppm and lowest at 0.1 until 10 ppm. The SNR curves mirrors the curves of SPR angle shift where the SNR increases with the Ni2+ concentrations. For the selectivity test, the CTA-NCC/GO has the abilities to differentiate Ni2+ in the mixture of metal ions.
In this study, the combination of novel valinomycin doped chitosan-graphene oxide (C-GO-V) thin film and surface plasmon resonance (SPR) system for potassium ion (K+) detection has been developed. The novel C-GO-V thin film was deposited on the gold surface using spin coating technique. The system was used to monitor SPR signal for K+ in solution with and without C-GO-V thin film. The K+ can be detected by measuring the SPR signal when C-GO-V thin film is exposed to K+ in solution. The sensor produces a linear response for K+ ion up to 100ppm with sensitivity and detection limit of 0.00948°ppm-1 and 0.001ppm, respectively. These results indicate that the C-GO-V film is high potential as a sensor element for K+ that has been proved by the SPR measurement.
2-(4-Chlorophenyl)-2-oxoethyl 3-nitrobenzoate is synthesized by reacting 4-chlorophenacyl bromide with 3-nitrobenzoic acid using a slight excess of potassium or sodium carbonate in DMF medium at room temperature. The structure of the compound was confirmed by IR and single-crystal X-ray diffraction studies. FT-IR spectrum of 2-(4-chlorophenyl)-2-oxoethyl 3-nitrobenzoate was recorded and analyzed. The crystal structure is also described. The vibrational wavenumbers were computed using HF and DFT methods and are assigned with the help of potential energy distribution method. The first hyperpolarizability and infrared intensities are also reported. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated (DFT) values. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. MEP was performed by the DFT method.
2-(4-Chlorophenyl)-2-oxoethyl 3-methylbenzoate is synthesized by reacting 4-chlorophenacyl bromide with 2-methylbenzoic acid using a slight excess of potassium or sodium carbonate in DMF medium at room temperature. The structure of the compound was confirmed by IR and single-crystal X-ray diffraction studies. FT-IR spectrum of 2-(4-chlorophenyl)-2-oxoethyl-3-nitrobenzoate was recorded and analyzed. The crystal structure is also described. The vibrational wavenumbers were computed using HF and DFT methods and are assigned with the help of potential energy distribution method. The first hyperpolarizability and infrared intensities are also reported. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated (DFT) values. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. MEP was performed by the DFT method.
The structure of (E)-1-(4-Bromophenyl)-3-(napthalen-2-yl)prop-2-en-1-one (C19H13BrO) crystallized in the triclinic system of P-1 space group. The unit cell dimensions are: a=5.8944 (9)Å, b=7.8190 (12)Å, c=16.320 (2)Å, α=102.4364 (19)°, β=95.943 (2)°, γ=96.274 (2)° and Z=2. The physical properties of this compound was determined by the spectroscopic methods (FTIR and (1)H and (13)C NMR). Quantum chemical investigations have been employed to investigate the structural and spectral properties. The molecular structure, vibrational assignments, (1)H and (13)C NMR chemical shift values, non-linear optical (NLO) effect, HOMO-LUMO analysis and natural bonding orbital (NBO) analysis were calculated using HF and DFT/B3LYP methods with 6-311++G(d,p) basis set in the ground state. The results show that the theoretical calculation of the geometrical parameters, vibrational frequencies and chemical shifts are comparable with the experimental data. The crystal structure is influenced and stabilized by weak C-H⋯π interactions connecting the molecules into infinite supramolecular one dimensional ladder-like arrangement. Additionally, this compound is evaluated for their antibacterial activities against gram positive and gram negative strains using a micro dilution procedure and shows activities against a panel of microorganisms.
2-(4-Chlorophenyl)-2-oxoethyl 2-chlorobenzoate has been synthesized, its structural and vibrational properties have been reported using FT-IR and single-crystal X-ray diffraction (XRD) studies. The conformational analysis, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the synthesized compound (C15H10Cl2O3) have been examined by means of Becke-3-Lee-Yang-Parr (B3LYP) density functional theory (DFT) method together with 6-31++G(d,p) basis set. Furthermore, reliable conformational investigation and vibrational assignments have been made by the potential energy surface (PES) and potential energy distribution (PED) analyses, respectively. Calculations are performed with two possible conformations. The title compound crystallizes in orthorhombic space group Pbca with the unit cell dimensions a=12.312(5) Å, b=8.103(3) Å, c=27.565(11) Å, V=2750.0(19) Å(3). B3LYP method provides satisfactory evidence for the prediction of vibrational wavenumbers and structural parameters.
The electronic absorption spectra of eight substituted acetic acids have been measured at room temperature in several solvents. The ground state dipole moments are evaluated experimentally for these molecules. These ground state values are used in conjunction with the spectral results to evaluate their first electronically excited state dipole moments. For all the molecules investigated here the dipole moments in the excited state are higher than their ground state values.
The heterocyclic chalcone containing thiophene ring 1-(4-chlorophenyl)-3-(2-thienyl)prop-2-en-1-one, C13H9ClOS was synthesized and investigated using experimental techniques such as nuclear magnetic resonance (1H and 13C NMR), Fourier transform infrared spectroscopy (FTIR) at room temperature, differential scanning calorimeter (DSC) from room temperature to 500K and Raman scattering at the temperature range 10-413K in order to study its structure and vibrational properties as well as stability and possible phase transition. Density functional theory (DFT) calculations were performed to determine the vibrational spectrum viewing to improve the knowledge of the material properties. A reasonable agreement was observed between theoretical and experimental Raman spectrum taken at 10K since anharmonic effects of the molecular motion is reduced at low temperatures, leading to a more comprehensive assignment of the vibrational modes. Increasing the temperature up to 393K, was observed the typical phonon anharmonicity behavior associated to changes in the Raman line intensities, line-widths and red-shift, in special in the external mode region, whereas the internal modes region remains almost unchanged due its strong chemical bonds. Furthermore, C13H9ClOS goes to melting phase transition in the temperature range 393-403K and then sublimates in the temperature range 403-413K. This is denounced by the disappearance of the external modes and the absence of internal modes in the Raman spectra, in accordance with DSC curve. The enthalpy (ΔH) obtained from the integration of the endothermic peak in DSC curve centered at 397K is founded to be 121.5J/g.
A novel (2E)-1-(5-chlorothiophen-2-yl)-3-(naphthalen-2-yl)prop-2-en-1-one [C17H11ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The isomers, optimized geometrical parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of the density functional theory method, employing, the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Reliable vibrational assignments and molecular orbitals have been investigated by the potential energy distribution and natural bonding orbital analyses, respectively. The compound crystallizes in the monoclinic space group P2₁/c with the unit cell parameters a=5.7827(8)Å, b=14.590(2)Å, c=16.138(2)Å and β=89.987 (°). The CC bond of the central enone group adopts an E configuration. There is a good agreement between the theoretically predicted structural parameters and vibrational frequencies and those obtained experimentally.
The structure of 2-acetyl-5-chlorothiophene (ACT) has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of ACT (C6H5ClOS) have been examined by the density functional theory, with the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Reliable vibrational assignments have been investigated by the potential energy distribution analysis. ACT crystallizes in monoclinic space group C2/c with the O,S-cis isomer. There is a good agreement between the theoretically predicted structural parameters and vibrational frequencies and those obtained experimentally.
Molecular structure and properties of 2-fluoro-4-bromobenzaldehyde (FBB, C7H4BrFO) was experimentally investigated by X-ray diffraction technique and vibrational spectroscopy. Experimental results on the molecular structure of FBB were supported with computational studies using the density functional theory, with the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Molecular dimer formed by the intermolecular hydrogen bonding was investigated. Potential energy distribution analysis of normal modes was performed to identify characteristic frequencies. FBB crystallizes in orthorhombic space group P2(1)2(1)2(1) with the O-trans conformation. In order to investigate halogen effect, the chloro- (CBB) and bromo- (BBB) analogs of FBB have also been studied theoretically. It is observed that all compounds prefer the stable O-trans conformation. Although the free energy difference between the O-cis and O-trans conformers is less than 2.5 kcal/mol, the free energy rotational barrier is at least 7.4 kcal/mol. There is a good agreement between the experimentally determined structural parameters, and vibrational frequencies of FBB and those predicted theoretically.
The structure of 3-iodobenzaldehyde (3IB) was characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The conformational isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of 3IB were examined using density functional theory (DFT) method, with the Becke-3-Lee-Yang-Parr (B3LYP) functional and the 6-311+G(3df,p) basis set for all atoms except for iodine. The LANL2DZ effective core basis set was used for iodine. Potential energy distribution (PED) analysis of normal modes was performed to identify characteristic frequencies. 3IB crystallizes in monoclinic space group P21/c with the O-trans form. There is a good agreement between the theoretically predicted structural parameters, and vibrational frequencies and those obtained experimentally. In order to understand halogen effect, 3-halogenobenzaldehyde [XC6H4CHO; X=F, Cl and Br] was also studied theoretically. The free energy difference between the isomers is small but the rotational barrier is about 8kcal/mol. An atypical behavior of fluorine affecting conformational preference is observed.
In the present work, the title chalcone, (2E)-3-(4-fluorophenyl)-1-(4-{[(1E)-(4-fluorophenyl) methylene]amino}phenyl)prop-2-en-1-one (abbreviated as FAMFC), was synthesized and structurally characterized by single-crystal X-ray diffraction. The compound is crystallized in the monoclinic system with non-centrosymmetric space group P21 and hence it satisfies the essential condition for materials to exhibit second-order nonlinear optical properties. The molecular structure was further confirmed by using FT-IR and 1H NMR spectroscopic techniques. The title crystal is transparent in the Vis-NIR region and has a direct band gap. The third-order nonlinear optical properties were investigated in solution (0.01M) by Z-scan technique using a continuous wave (CW) DPSS laser at the wavelength of 532nm. The title chalcone exhibited significant two-photon absorption (β=35.8×10-5cmW-1), negative nonlinear refraction (n2=-0.18×10-8cm2W-1) and optical limiting (OL threshold=2.73kJcm-2) under the CW regime. In support of the experimental results, a comprehensive theoretical study was carried out on the molecule of FAMFC using density functional theory (DFT). The optimized geometries and frontier molecular orbitals were calculated by employing B3LYP/6-31+G level of theory. The optimized molecular structure was confirmed computationally by IR vibrational and 1H NMR spectral analysis. The experimental UV-Vis-NIR spectrum was interpreted using computational chemistry under time-dependent DFT. The static and dynamic NLO properties such as dipole moments (μ), polarizability (α), and first hyperpolarizabilities (β) were computed by using finite field method. The obtained dynamic first hyperpolarizability β(-2ω;ω,ω) at input frequency ω=0.04282a.u. is predicted to be 161 times higher than urea standard. The electronic excitation energies and HOMO-LUMO band gap for FAMFC were also evaluated by DFT. The experimental and theoretical results are in good agreement, and the NLO study suggests that FAMFC molecule can be a potential candidate in the nonlinear optical applications.
A greener method based on cloud point extraction was developed for removing phenol species including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 4-nitrophenol (4-NP) in water samples by using the UV-Vis spectrophotometric method. The non-ionic surfactant DC193C was chosen as an extraction solvent due to its low water content in a surfactant rich phase and it is well-known as an environmentally-friendly solvent. The parameters affecting the extraction efficiency such as pH, temperature and incubation time, concentration of surfactant and salt, amount of surfactant and water content were evaluated and optimized. The proposed method was successfully applied for removing phenol species in real water samples.
Cancer is increasing in incidence and the leading cause of death worldwide. Controlling and reducing cancer requires early detection and technique to accurately detect and quantify predictive biomarkers. Optical spectroscopy has shown promising non-destructive ability to display distinctive spectral characteristics between cancerous and normal tissues from different part of human organ. Nonetheless, not many information is available on spectroscopic properties of cancer cell lines. In this research, the visible-near infrared (VIS-NIR) absorbance spectroscopy measurement of cultured cervical cancer (HeLa) and prostate cancer cells (DU145) lines has been performed to develop spectral signature of cancer cells and to generate algorithm to quantify cancer cells. Spectroscopic measurement on mouse skin fibroblast (L929) was also taken for comparative purposes. In visible region, the raw cells' spectra do not produce any noticeable peak absorbance that provides information on color because the medium used for cells is colorless and transparent. NIR wavelength between 950 and 975 nm exhibit significant peak due to water absorbance by the medium. Development of spectral signature for the cells through the application of regression technique significantly enhances the diverse characteristics between L929, HeLa and DU145. The application of multiple linear regression allows high measurement accuracy of the cells with coefficient of determination above 0.94.
Gold nanoparticles (AuNPs) stabilized by new cationic 1‑(3‑(acetylthio)propyl)pyrazin‑1‑ium ligand (PPTA) were synthesized. AuNPs stabilized by PPTA (PPTA-AuNPs) were found to be spherical and polydispersed with the average size of 60 nm. Human neuroblastoma (SHSY-5Y) cells permeability of PPTA-AuNPs was found to be a key feature to study the intracellular quenching of Fe(III) proliferative activity. In vitro MTT assay revealed non-cytotoxicity of PPTA and PPTA-AuNPs at 100 μM concentration, while treatment of 100 μM of Fe(III) with SHSY-5Y cells resulted into higher cells viability. Contrary, a mixture of 1:1 Fe(III) with PPTA-AuNPs showed no change in the viability of cells at same concentration which suggests the intracellular complexation and recognition of Fe(III) by PPTA-AuNPs. AFM morphological analysis of SHSY-5Y cells also supported the MTT assay results, and it is safe to conclude that PPTA-AuNPs can be used as Fe(III) probes in living cells. In addition, Fe(III) caused a significant decrease in the absorbance of surface plasmon resonance (SPR) band of PPTA-AuNPs in a wide range of concentration and pH, with limit of detection 4.3 μM. Moreover, the specific response of PPTA-AuNPs towards Fe(III) was unaffected by the interference of other metals and components of real samples of tap water.
Polymer electrolytes based on poly(ethylene oxide)-lithium triflate (PEO-LiCF3SO3) and poly(ethylene oxide)-lithium sulphate (PEO-Li2S4) were prepared by using solution casting method. Measurements of conductivity and dielectric were carried out on these films as a function of frequency at various temperatures. It was observed that PEO-LiCF3SO3 polymer electrolytes have higher conductivity. The interaction between PEO and Li salts were studied by Fourier transform infrared (FTIR).