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We report the growth and characterization of gadolinium oxide films deposited on Si͑100͒ and fused quartz in the temperature range of 450-800°C by a low-pressure metalorganic chemical vapor deposition technique using a ␤-diketonate complex of gadolinium as the precursor. The x-ray diffractometry study of the films reveals that, irrespective of the growth temperature, the films grown on fused quartz (i.e., an amorphous substrate) and silicon (i.e., a single-crystal substrate) comprise the cubic Gd 2 O 3 phase with a (111) texture. However, the films grown on fused quartz at higher temperatures also show the presence of the monoclinic phase of Gd 2 O 3 . The growth of strongly oriented films on fused quartz has been understood on the basis of minimization of the surface energy. The scanning electron microscopy and atomic force microscopy studies reveal that the films grown at or above 525°C are densely packed and grainy. Optical properties of the films, as studied by ultraviolet (UV)-visible spectrophotometry and Fourier transform infrared spectroscopy, are found to depend strongly on the chemical vapor deposition condition. The analyses reveal further that the films grown at or above 500°C are free of heteroatoms, i.e., C, N, and H. The optical band gap of the films is in the range of 5.0-5.4 eV. Electrical characterization was carried out on Al/ Gd 2 O 3 / Si metal-insulator-semiconductor structures by capacitance-voltage ͑C -V͒ and current-voltage analyses. The effective dielectric constant of the films was in the range of 7-23. The bidirectional C -V characteristics show a counterclockwise hysteresis due to the presence of slow interface traps. A minimum leakage current of 4.6ϫ 10 -5 A/cm 2 at the 1-MV/ cm field was demonstrated.

The kinetics of the reaction between formaldehyde and hexacyanoferrate(II1) ion in alkaline medium has been investigated at four temperatures. The data show that the reaction is rapid initially, then follows a simple first order rate with respect to each of the hexacyanoferrate(II1) ion, formaldehyde, and hydroxide ion. Calculations reveal that only 0.27 % of the formaldehyde corresponds to the initial rapid reaction; the remaining 99.73 % follows the kinetics described. The net rate of the oxidation of formaldehyde as measured by the consumption of hexacyanoferrate(JI1) ion, is given by

A new chiral derivatizing reagent has been synthesized from (S)-(+)-naproxen and was used for C-N bond formation to prepare diastereomeric amides of (RS)-propranolol, (RS)atenolol, (RS)-carvedilol and (RS)-metoprolol. Derivatization reactions were done at room temperature (30 • C for 30 min) under stirring conditions as well as under microwave irradiation (MWI). Separation of diastereomers was achieved by open column chromatography. 1 H NMR spectra of the isolated and purified diastereomers were recorded to establish the configurations of the first and second eluting diastereomers (and thus the elution order) and to compare the chromatographic separation characteristics when the diastereomeric mixture was separated using achiral RP-HPLC (using C 18 column and a binary mixture of MeCN and triethyl ammonium phosphate buffer of pH 3.5 (60:40 v/v) as mobile phase at a flow rate of 1 mL min -1 and UV detection at 230nm). No racemization was observed throughout the study. Test samples of β-blockers were isolated from commercial tablets and then were purified and characterized to be used as racemic standard. The conditions for derivatization and separation were optimized. Lowest energy optimized structures of the two diastereomers were developed using the Gaussian 09 Rev. A.02 program and hybrid density functional B3LYP with 6-31G basis set which supplemented 1 H NMR interpretations and confirmed three dimensional geometry of the diastereomers. Separation method was validated as per ICH guidelines. The limit of detection and limit of quantification for each isomer were 0.4 ng/mL and 1.2 ng/mL, respectively. Stability of Diastereomers:Stability of diastereomers was investigated after short-term (room temperature) and long term (refrigerated at a temperature of 3-5 °C) storage as a function of storage conditions including the container system and their chemical properties. The evaluation also included the stability of the analyte in stock solution and situations encountered during actual sample handling and analysis. HPLC experiments were carried out at an interval of 10 days up to 130 days from the day of synthesis of the diastereomers and it was found that the diastereomers were stable for 120 days under refrigeration conditions (3-5 °C). The chemical stability remains unaffected in the solvents used as mobile phase in HPLC.

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