The synthesis and characterization of a series of silver pyrazolate complexes [Ag(tfpz)] 3 (1), [Ag(fbpz)] 3 (2), [Ag(dbpz)] 3 (3), and [(py)Ag(tfpz)] 2 (4) are reported, for which tfpz, fbpz, dbpz are abbreviations for the pyrazolate ligands with formulae 3,5-(CF 3 ) 2 -pz, 3-t Bu-5-(CF 3 )-pz, and 3,5-( t Bu) 2 -pz, respectively. These silver complexes were characterized by microanalysis and spectroscopic methods. The CF 3 -substituted complex 1 possesses the highest volatility and stability against thermal decomposition. Low pressure CVD experiments were conducted over the temperature range 250±350 C. Silver metal thin films were successfully obtained on silicon wafers using pure H 2 as the carrier gas. Scanning electron microscopy (SEM) was used to reveal surface morphologies, while X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were utilized to determine the atomic composition of the as-deposited thin films as well as the crystallite packing.

Volatile low-melting CuII metal complexes Cu[OC(CF3)2CH2C(Me)=NMe]2 (4) and Cu[OC(CF3)2CH2CHMeNHMe]2 (5) were synthesized and characterized by spectroscopic methods. A single-crystal X-ray diffraction study on complex 4 shows the anticipated N2O2 square-planar geometry with the imino alcoholate ligand arranged in the all-trans orientation. In contrast, a highly distorted N2O2 geometry with a dihedral angle of 33 degrees was observed for complex 5, suggesting that the fully saturated amino alcoholate ligand produces a much greater steric congestion around the metal ion. Metal CVD experiments were conducted, showing that both complexes, 4 and 5, are capable of depositing copper metal at temperatures of 275-300 degrees C using an inert argon carrier gas mixed with low concentrations (2-8%) of O2. The best copper thin film showed a purity of approximately 96 at. % and a resistivity of 2.11 microOmega cm versus that of the bulk standard (1.7 microOmega cm), as revealed by XPS and four-point probe analyses, respectively. We speculate that the low concentration of O2 promotes partial ligand oxidation, thus releasing the reduced copper on the substrate and affording the high-purity copper deposit.

Silicon nitride (SiN(x)) and parylene thin films were deposited onto flexible polyimide (PI) substrates using plasma-enhanced chemical vapor deposition and a parylene reactor for transparent barrier applications. The PI substrates from the Industry Technology Research Institute with high optical transmittance and high glass transition temperature were used. A relatively high growth temperature of 200 degrees C was chosen to deposit the SiN(x) films. To characterize the SiN(x) films deposited under different growth temperatures, a wet-etching process was performed to visualize the defect distribution in the barrier films. After 120 min of etching, the etching area ratio decreased from 44.9 to 6.7%, while the average defect spacing increased from 125 to 450 mu m with increasing growth temperature. Under room temperature and relative humidity of 50%, four SiN(x)/parylene stacks with the SiN(x) films deposited at 80 and 200 degrees C were demonstrated to decrease the water vapor transmission rate to 7.9x10(-4) and 7.41x10(-6) g/m(2)/day, respectively. As a result, ultralow permeation can be achieved with less repeating barrier stacks by using high temperature deposited SiN(x) films in the barrier structures

New CVD Precursors Capable of Depositing Copper Metal under Mixed O 2 /ArAtmosphere. -The structure of the Cu complexes (VI) (orthorhombic, space group Pna21, Z = 4) and (VII) (monoclinic, P2/n, 2) are determined by single crystal XRD. CVD experiments show that both complexes are capable of depositing high-quality Cu 0 films at temperatures of 275-300°C using an inert argon carrier gas with low O2 concentrations (2-8%). The best copper thin film showed a purity of ≈96 at.% and a resistivity of 2.1 µΩ·cm (bulk standard 1.7 µΩ·cm). -(LAY, E.; SONG, Y.-H.; CHIU, Y.-C.; LIN, Y.-M.; CHI*, Y.; CARTY, A. J.; PENG, S.-M.; LEE, G.-H.; Inorg. Chem. 44 (2005) 20, 7226-7233; Dep. Chem., Natl. Tsing Hua Univ., Hsinchu 30043, Taiwan; Eng.) -Schramke 50-212

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By using strong neutral bases as catalyst, a detailed investigation of the racemization of (S)‐naproxen 2,2,2‐trifluoroethyl ester was conducted in the non‐polar solvents isooctane, cyclohexane and n‐hexane. The second‐order interconversion constant $k^*_{\rm int}$ as representing the ion‐pair kinetic basicity in isooctane was first estimated and correlated with the equilibrium ion‐pair basicity pKip in tetrahydrofuran, giving slopes of 0.768 and 0.689 for non‐phosphazene and phosphazene bases, respectively, in the Brønsted correlations. The result was further compared with that for (S)‐naproxen 2,2,2‐trifluoroethyl thioester, showing about a 1–2 orders of magnitude enhancement of $k^*_{\rm int}$ for the corresponding thio‐containing analogue. A smaller influence of non‐polar solvents (i.e. isooctane, n‐hexane and cyclohexane) on $k^*_{\rm int}$ was found. Kinetic analysis of the racemization and hydrolysis of (S)‐naproxen 2,2,2‐trifluoroethyl ester in isooctane and n‐hexane containing 7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene and water suggests nucleophilic hydrolysis by the base, where the breakdown of tetrahedral intermediates IR1 and IS1 is the rate‐limiting step and the hydrolysis constant khy is in proportion to the product of base and ion‐pair concentrations. Copyright © 2004 John Wiley & Sons, Ltd.