Phenylarsenic(III) complexes of 2-(2-hydroxyphenyl)benzothiazolines

Equimolar reactions of PhAs(OMe)₂ (prepared in situ) and 2-(2-hydroxyphenyl)benzothiazolines LH₂ give the addition products PhAs(OMe)₂LH₂, while equimolar reactions of PhAsCl₂ with Na₂L yield substitution products PhAsL. All these derivatives have been characterized by elemental analyses and their plausible structures have been established on the basis of physico-chemical, IR, and NMR (¹H and ¹³C) spectral studies. © 2003 Wiley Periodicals, Inc. 15:92–96, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.10220     

Influence of thermal annealing on the composition and structural parameters of DC magnetron sputtered titanium dioxide thin films

Titanium dioxide films have been deposited using DC magnetron sputtering technique. Films were deposited onto RCA cleaned p‐silicon substrates at the ambient temperature at an oxygen partial pressure of 7 × 10^–5 mbar and sputtering pressure of 1 × 10 ^–3 mbar. The deposited films were annealed in the temperature range 673–873 K. The structure and composition of the films were confirmed using X‐ray diffraction and Auger electron spectroscopy. The structure of the films deposited at the ambient was found to be amorphous and the films annealed at 673 K and above were crystalline with anatase structure. The lattice constants, grain size, microstrain and the dislocation density of the film are calculated and correlated with annealing temperature.     

Crystalline Anions Based on Classical N-Heterocyclic Carbenes

Herein, the first stable anions K[SIPr^Bp] ( 4 a-K ) and K[IPr^Bp] ( 4 b-K ) (SIPr^Bp=BpC{N(Dipp)CH₂}₂, IPr^Bp=BpC{N(Dipp)CH}₂; Bp=4-PhC₆H₄; Dipp=2,6-iPr₂C₆H₃) derived from classical N-heterocyclic carbenes (NHCs) (i.e. SIPr and IPr) have been isolated as violet crystalline solids. 4 a-K and 4 b-K are prepared by KC₈ reduction of the neutral radicals [SIPr^Bp] ( 3 a ) and [IPr^Bp] ( 3 b ), respectively. The radicals 3 a and 3 b as well as [Me-IPr^Bp] 3 c (Me-IPr^Bp=BpC{N(Dipp)CMe}₂) are accessible as crystalline solids on treatment of the respective 1,3-imidazoli(ni)um bromides (SIPr^Bp)Br ( 2 a ), (IPr^Bp)Br ( 2 b ), and (Me−IPr^Bp)Br ( 2 c ) with KC₈. The cyclic voltammograms of 2 a–2 c exhibit two one-electron reversible redox processes in −0.5 to −2.5 V region that correspond to the radicals 3 a–3 c and the anions ( 4 a–4 c )⁻. Computational calculations suggest a closed-shell singlet ground state for ( 4 a–4 c )⁻ with the singlet-triplet energy gap of 17–24 kcal mol⁻¹.