Photochemical reduction of carbonate to formaldehyde on TiO2 powder

Photochemical reactions at semiconductor particle surfaces have been used to drive energy uphill reactions to store light energy. Carbonate radical anion was found to be intermediate when carbonate was used to intercept the photogenerated hole on TiO₂ by exciting with light energy of more than 3.2 eV. The carbonate anion radical undergoes secondary reactions on the surface to give formaldehyde. The chemical energy stored in this reaction is 580 kj/mole. The quantum yield for the formation of HCHO is 4 × 10^?3, but extended irradiation leads to loss of formaldehyde.     

Structural and Thermal Investigations of Biomimetically Grown Casein–Soy Hybrid Protein Fibers

A hybrid protein fiber from different protein sources such as casein and soybean using wet-spinning technique was prepared. The casein/soybean hybrid fibers were synthesized at different weight ratios such as 100/0 (casein), 75/25, 50/50, 25/75, and 0/100 (soy) and characterized. Electron microscopic analysis confirmed the growth of pure and hybrid fibers and shows an increased surface roughness as the soy concentration increases in the hybrid fibers. Infrared spectra did not exhibit any significant changes in the functional groups between pure and hybrid fibers. X-ray diffraction pattern indicates slight increase in the diffraction peak values of hybrid fibers compared with the neat fibers. Thermal analyses show a moderate increase in the thermal stability of hybrid fibers when compared with the pure fibers. These results implicitly indicate that the casein and soy proteins are homogeneous in the hybrid fiber form. It has been demonstrated that the hybrid fiber with ≥50 wt.% casein content exhibits better morphology and increased thermal stability, which has scope for application in technical and medical industries.     

Synthesis, growth and characterization of l-valine cadmium chloride monohydrate—A novel semiorganic nonlinear optical crystal

Single crystals of l-valine cadmium chloride monohydrate (LVCC), a novel semiorganic nonlinear optical material were synthesized and grown from aqueous solution by slow evaporation method at room temperature. The powder X-ray diffraction pattern and FT IR spectrum analysis confirmed the formation of the new crystal. LVCC has good optical transmission in the entire visible region, which is an essential requirement for a nonlinear crystal. The thermal studies reveal that the material has good thermal stability. The LVCC crystal was characterized by energy dispersive X-ray analysis. The optical second harmonic generation conversion efficiency of LVCC was determined using Kurtz powder technique.     

A unique quinolineboronic acid-based supramolecular structure that relies on double intermolecular B-N bonds for self-assembly in solid state and in solution

The boronic acid functional group plays very important roles in sugar recognition, catalysis, organic synthesis, and supramolecular assembly. Therefore, understanding the unique properties of this functional group is very important. 8-Quinolineboronic acid (8-QBA) is found to be capable of self-assembling in solid state through a unique intermolecular B-N bond mechanism reinforced by intermolecular boronic anhydride formation, π-π stacking, and hydrogen bond formation. NMR NOE and diffusion studies indicate that intermolecular B-N interaction also exists in solution with 8-QBA. In contrast, a positional isomer of 8-QBA, 5-quinolineboronic acid (5-QBA) showed very different behaviors in crystal packing and in solution and therefore different supramolecular network. Understanding the structural features of this unique 8-QBA assembly could be very helpful for the future design of new sugar sensors, molecular catalysts, and supramolecular assemblies.     

Application of capillary isotachophoresis-based multidimensional separations coupled with electrospray ionization-tandem mass spectrometry for characterization of mouse brain mitochondrial proteome

By employing a capillary ITP (CITP)/CZE-based proteomic technology, a total of 1795 distinct mouse Swiss-Prot protein entries (or 1705 nonredundant proteins) are identified from synaptic mitochondria isolated from mouse brain. The ultrahigh resolving power of CITP/CZE is evidenced by the large number of distinct peptide identifications measured from each CITP fraction together with the low peptide fraction overlapping among identified peptides. The degree of peptide overlapping among CITP fractions is even lower than that achieved using combined CIEF/nano-RP LC separations for the analysis of the same mitochondrial sample. When evaluating the protein sequence coverage by the number of distinct peptides mapping to each mitochondrial protein identification, CITP/CZE similarly achieves superior performance with 1041 proteins (58%) having 3 or more distinct peptides, 233 (13%) having 2 distinct peptides, and 521 (29%) having a single distinct peptide. The reproducibility of protein identifications is found to be around 86% by comparing proteins identified from repeated runs of the same mitochondrial sample. The analysis of the mouse mitochondrial proteome by two CITP/CZE runs results in the detection of 2095 distinct mouse Swiss-Prot protein entries (or 1992 nonredundant proteins), corresponding to 59% coverage of the updated Maestro mitochondrial reference set. The collective analysis from combined CITP/CZE and CIEF-based proteomic studies yields the identification of 2191 distinct mitochondrial protein entries (or 2082 nonredundant proteins), corresponding to 76% coverage of the MitoP2-database reference set.     

Enantioseparation of 3-Hydroxycarboxylic Acids via Diastereomeric Salt Formation by 2-Amino-1,2-diphenylethanol (ADPE) and Cinchonidine

Enantioseparation of 3-hydroxycarboxylic acids via diastereomeric salt formation was demonstrated using 2-amino-1,2-diphenylethanol (ADPE) and cinchonidine as the resolving agents. Racemic 3-hydroxy-4-phenylbutanoic acid (rac-1), 3-hydroxy-4-(4-chlorophenyl)butanoic acid (rac-2), and 3-hydroxy-5-phenylpentanoic acid (rac-3) were efficiently resolved using these resolving agents. Moreover, the successive crystallization of the less-soluble diastereomeric salt of 1 and cinchonidine using EtOH yielded pure (R)-1 · cinchonidine salt in a high yield. The crystal structures of less-soluble diastereomeric salts were elucidated and it was revealed that hydrogen bonding and CH/π interactions play an important role in reinforcing the structure of the less-soluble diastereomeric salts.     

A 3-V electrochemical capacitor study based on a magnesium polymer gel electrolyte by three different carbon materials

An organic medium with lithium and sodium salts is not so safe in some cases. Structural features of carbon electrodes play a vital role on the capacitor parameters. Based on that above said, we have studied three kinds of supercapacitors using a gel electrolyte from 0.5 M of magnesium imide salt–polyethylene oxide (PEO) in propylene carbonate (PC). The cell electrodes were carbide derived carbon (CDC), PICACTIF and YECA activated carbons. The gel component interactions were viewed by infrared spectroscopy. The cell reversibility and symmetric were analyzed using cyclic voltammetry (CV) technique. Linear sweep voltammetry (LSV) technique was taken to approximate the electrolyte stability. Electrochemical impedance spectroscopy (EIS) result reflects the resistance and capacitive behavior of the cells, i.e., The YECA carbon shows a good capacitive behavior over the CDC- and PICACTIF-based cells whereas the CDC cell has shown a low resistance. Galvanostatic charge-discharge study (CD) results have shown a stable and ideal 2.5-V capacitor behavior. The capacitors have also proven an obtainable good specific capacitance, real power, and real energy density of ~25 F g^?1, 0.7 kW kg^?1, and 25 W·h kg^?1, respectively. Moreover, the cells were tested for 3-V limit.     

Benzyltriethylammon Tetrathiomolybdate: An Improved Sulfur Transfer Reagent for the Synthesis of Disulfides

Benzyltriethylammonium tetrathiomolybdate has been found to be a superior reagent for the conversion of alkyl halides to the corresponding disulfides in chloroform at room temperature.     

Regio- and stereoselective synthesis of aziridino epoxides from cyclic dienes

Two different routes for the regio- and stereoselective synthesis of aziridino epoxides from cyclic dienes have been explored. The first strategy involves regiospecific aziridination of cyclic diene derivatives and subsequent epoxidation with m-CPBA to yield cis-aziridino epoxides as major products. The second strategy utilizes regiospecific epoxidation of cyclic diene derivatives followed by Sharpless aziridination to provide exclusively trans-aziridino epoxides. Synthesis of both enantiomers of cis-aziridino epoxides from (R)-(-)- and (S)-(+)-carvones are also reported.     

Phase analysis and magnetocaloric properties of Zr substituted Gd-Si-Ge alloys

The structure, microstructure, magneto-structural transition and magnetocaloric effect have been investigated in series of (Gd_5−xZr_x)Si₂Ge₂ alloys with 0≤x≥0.20. X-ray powder diffraction analysis revealed the presence of orthorhombic structure for Zr containing alloys at room temperature in contrast to the monoclinic structure observed in the parent Gd₅Si₂Ge₂ alloy. The microstructural studies reveal that, low Zr addition (x≤0.1) resulted in low volume fraction of detrimental Gd₅Si₃-type secondary phase compared to that present in the parent alloy. All the Zr containing alloys have shown the presence of only second order magnetic transition unlike the parent alloy showing both first order structural and second order magnetic transition. A moderate (ΔS)_M value of −5.5 J/kg K was obtained for the x=0.05 alloy at an enhanced operating temperature of 292 K compared to −7.8 J/kg K at 274 K of the parent alloy for an applied field of 2 T. The interesting feature of Zr (x=0.05) containing alloy is the wide operating temperature range of ∼25 K than that of ∼10-12 K for the parent, which resulted in enhanced net refrigerant capacity of 103 J/kg compared to that of 53 J/kg for the parent alloy.