2-Amino-6-methyl-pyridinium 4-methyl-benzene-sulfonate.

In the asymmetric unit of the title salt, C6H9N2 (+)·C7H7O3S(-), there are two independent 2-amino-6-methyl-pyridinium cations and two independent 4-methyl-benzene-sulfonate anions. Both cations are protonated at their pyridine N atoms and their geometries reveal amine-imine tautomerism. In the 4-methyl-benzene-sulfonate anions, the carboxyl-ate groups are twisted out of the benzene ring planes by 88.4 (1) and 86.2 (2)°. In the crystal, the sulfonate O atoms of an anion inter-act with the protonated N atoms and the 2-amino groups of a cation via a pair of N-H⋯O hydrogen bonds, forming an R 2 (2)(8) ring motif. These motifs are connected via N-H⋯O hydrogen bonds, forming chains running along the a-axis direction. Within the chains there are weak C-H⋯O hydrogen bonds present. In addition, aromatic π-π stacking inter-actions [centroid-centroid distances = 3.771 (2), 3.599 (2), 3.599 (2) and 3.497 (2) Å] involving neighbouring chains are also observed.

Structural, optical, and thermoluminescence characterizations of 1 mol% Dy3+ion-activated Fluro Boro-phosphate glass for photonic devices.

A novel Fluro boro-phosphate host matrix doped with the 1 mol% of Dy3+ ions (50B2O3 + 20P2O5 + 10TiO2 + 10SrCO3 + 4BaF2 + 5BaCO3 + 1Dy2O3) was prepared using a conventional melt-quenching mechanism, and its structural characteristics were explored through the Powder-XRD, FT-IR, FT-Raman, EDAX and SEM spectroscopic analysis. The XRD spectrum of the glass confirmed its non-crystalline or amorphous structure. FT-IR and FT-Raman spectrum studies revealed that various borate and phosphate groups present with a variety of stretching and bending vibrations. Scanning Electron Microscope (SEM) and Energy Dispersive X-ray analysis (EDAX) analysis have been used to examine the surface morphology and the presence of elements, respectively in the prepared glass. The optical absorption spectrum was used to explore the electronic band structure through the measurements of optical band-gap energy and Urbach energy. The luminescence spectrum reveals the emission characteristics of Dy3+ ions due to the electric-dipole and magnetic-dipole transitions. It is found that the decay time of the 4F9/2 excited level at a concentration of 1 mol% Dy3+ in the glass matrix is tri-fit non-exponential. The CIE chromaticity coordinates and the concentration influence on Y/B intensity ratios were computed for the creation of white light from the luminescence spectrum. The present work also discusses the findings after figuring out the correlated color temperature associated (CCT) with the color purity (Pe). The Thermoluminescence (TL) characteristics and the kinetic parameters of the glass were studied after the γ-irradiation with a dose of 2 kGy. EPR investigation revealed the paramagnetic characteristics through the hyperfine structure of Dy3+ ions and the electron-hole pair formation upon irradiation in the glass matrix.

Effects of Ce3+/Dy3+ and Ce3+/Sm3+ co-doping as a luminescent modifier in alumina-borophosphate glasses for w-LED application.

Ce3+/Dy3+ and Ce3+/Sm3+ co-doped alumino-borophosphate glasses (CDABP/ CSABP) were prepared and characterized for luminescence and SHG efficiency properties. FT-IR and FT-Raman spectra have been utilized to identify different functional groups of Phosphate networks. Various optical properties such as, optical absorption, optical band gap energy (Eg), Urbach energy (ΔE) and linear refractive index (n) of the glasses were determined using UV-Vis spectrometer in the spectral range 200-1200 nm. Scanning Electron Microscopy/Energy Dispersive spectrometry (SEM/EDS) reveals information about the elemental compositional homogeneity as well as the surface morphology of the prepared glasses. Influences of a luminescence co-activator of Ce3+/Dy3+ and Ce3+/Sm3+ ions in alumina-borophosphate glasses were interpreted under the excitation wavelength of 300 nm. Two emission peaks detected at 426 nm (blue) and 574 nm (Yellow) in CDABP glass corresponding to the Dy3+, whereas three emission peaks traced at 558 nm (green), 598 nm (orange) and 652 nm, (red) in CSABP glass corresponding to the Sm3+. The Influence of internal and external quantum efficiency (QE) on the glass's photoluminescence spectrum was measured. The CIE chromaticity obtained from the luminescence spectra, confirming that the CSABP glass emits white light. The colour purity (Pc) and excitation purity (Pe) of the glasses were investigated in order to quantify the quality of light emitted by them. The second harmonic generation (SHG) efficiency of the synthesized glasses was determined without the need of a thermal polling mechanism, and the magnitude was compared to that of Urea and KDP crystal reference samples.