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Novel Precursor (novel + precursor)
Selected AbstractsLiquid-Injection MOCVD of ZrO2 Thin Films using Zirconium Bis(diethlyamido)-bis(di- tert -butylmalonato) as a Novel Precursor,CHEMICAL VAPOR DEPOSITION, Issue 5 2006R. Thomas Abstract The stabilization of highly reactive amide complexes of zirconium diethylamide with malonates as chelating ligands leads to a stable six-coordinated monomeric complex which shows promise for CVD applications. This novel precursor, zirconium bis-(diethylamido)bis(di- tert -butylmalonato) zirconium, [Zr(NEt2)2(dbml)2], has been characterized and tested in a production-type MOCVD reactor for ZrO2 thin-film deposition. Up to 450,°C, the ZrO2 films are amorphous, and above 475,°C films they are crystalline. Atomic force microscopy (AFM) shows a lower roughness (,2.5Å) for as-deposited amorphous films compared to crystalline films (,6.0,Å); however, smooth crystalline films can be obtained by post-deposition annealing of amorphous films. Electrical properties are investigated for Pt/ZrO2/SiOx/Si capacitor structures. Relative dielectric permittivity reaches a bulk value of 24, and leakage currents for typically 4,nm thick films are below 10,4,A,cm,2 at a bias of ,1,V. Hence, the precursor shows promising properties for possible application in the deposition of high- k gate oxide (MIS) and high- k dielectric (MIM) structures. [source] O-Protected 3-Hydroxy-oxazolidin-2,4-diones: Novel Precursors in the Synthesis of ,-Hydroxyhydroxamic Acids.CHEMINFORM, Issue 47 2004Thomas Kurz Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of ansa- [n]Silacyclopentadienyl,Cycloheptatrienyl,Chromium Complexes (n = 1, 2): Novel Precursors for Polymers Bearing Chromium in the BackboneCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2006Alexandra Bartole-Scott Abstract Reaction of [(,5 -C5H4Li)(,7 -C7H6Li)Cr],tmeda with a variety of dialkyl(dichloro)silanes in aliphatic solvents afforded the corresponding [1]silatrochrocenophanes. Structural characterization by X-ray diffraction analysis of the [1]silatrochrocenophanes bearing Me2Si, (iPr)2Si, and silacyclobutane bridges revealed tilt angles , of 15.56(12)°, 15.8(1)°, and 16.33(17)°, respectively. Analogously, a [2]silatrochrocenophane (6) was prepared in excellent yield by reaction of [(,5 -C5H4Li)(,7 -C7H6Li)Cr],tmeda with 1,2-dichloro-1,1,2,2-tetramethyldisilane. This complex also was characterized structurally and exhibited a tilt angle , of 2.60(15)°. The [1]silatrochrocenophane bearing the Me2Si bridge underwent facile and regioselective carbon,silicon bond cleavage with [Pt(PEt3)4] to give a very high yield of an oxidative addition product. The ring-opening polymerization of these novel [1]silatrochrocenophanes afforded ring-opened chromium-based polymers. [source] 2-(Benzylsulfanyl)-6-chloro-9-isopropylpurine, a Valuable Intermediate in the Synthesis of Diaminopurine Cyclin Dependent Kinase InhibitorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 5 2005David Taddei Abstract The synthetic potential of a novel precursor of 2,6-diaminopurine CDK inhibitors, 2-(benzylsulfanyl)-6-chloro-9-isopropylpurine, is described. The Traube purine synthesis was chosen to prepare the required 2-(benzylsulfanyl)hypoxanthine intermediate. Attempts to prepare its purin-6-yl methanesulfonic ester analogue failed. Conversion to the 6-chloropurine derivative enabled the introduction of arylamines in the presence of catalytic amounts of acid. Further chemical variety was introduced on the purine through a regioselective Mitsunobu N -9 alkylation. Oxidative cleavage of the 2-(benzylsulfanyl) leaving group with an aliphatic amine was implemented as previously reported. Purvalanol A, a potent CDK inhibitor, was synthesised using this methodology. The template and intermediates were fully characterised by modern spectroscopic techniques and single-crystal X-ray diffraction. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] 2,4,6-Tris[2-(trimethylsilyl)ethynyl]-1,3,5-triazene: a novel precursor to C,N two-dimensional structuresACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2000John Kouvetakis The title structure, C18H27N3Si3, consists of separate molecules arranged in sheets parallel to the ab plane. In each molecule, the central (CN)3 ring, the ethynyl units, and the Si atoms lie in the same plane. Typical C,C and C,N bond distances are 1.197,(5) and 1.42,(4),Å, respectively. The angles inside the (CN)3 ring range from 114,(3) to 125,(3)° and the acetylenic branches are nearly linear. [source] Liquid-Injection MOCVD of ZrO2 Thin Films using Zirconium Bis(diethlyamido)-bis(di- tert -butylmalonato) as a Novel Precursor,CHEMICAL VAPOR DEPOSITION, Issue 5 2006R. Thomas Abstract The stabilization of highly reactive amide complexes of zirconium diethylamide with malonates as chelating ligands leads to a stable six-coordinated monomeric complex which shows promise for CVD applications. This novel precursor, zirconium bis-(diethylamido)bis(di- tert -butylmalonato) zirconium, [Zr(NEt2)2(dbml)2], has been characterized and tested in a production-type MOCVD reactor for ZrO2 thin-film deposition. Up to 450,°C, the ZrO2 films are amorphous, and above 475,°C films they are crystalline. Atomic force microscopy (AFM) shows a lower roughness (,2.5Å) for as-deposited amorphous films compared to crystalline films (,6.0,Å); however, smooth crystalline films can be obtained by post-deposition annealing of amorphous films. Electrical properties are investigated for Pt/ZrO2/SiOx/Si capacitor structures. Relative dielectric permittivity reaches a bulk value of 24, and leakage currents for typically 4,nm thick films are below 10,4,A,cm,2 at a bias of ,1,V. Hence, the precursor shows promising properties for possible application in the deposition of high- k gate oxide (MIS) and high- k dielectric (MIM) structures. [source] Cyclodextrin inclusion complexes as novel MOCVD precursors for potential cobalt oxide depositionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 2 2010N. D. Papadopoulos Abstract The potential use of the inclusion complexes of ,-cyclodextrins with metal halides as novel precursors in MOCVD applications was examined in terms of microstructure, thermal stability and chemical modifications during heating. The investigation was especially focused on the inclusion complex of ,-cyclodextrin with cobalt iodide for cobalt oxide thin film deposition. The general composition assigned to the dextrin's inclusion complex was: (,-CD)2,CoI7,11H2O. It was found that the inclusion complex of ,-cyclodextrin with CoI2 may prove a promising alternative to traditional metalorganic or organometallic Co-precursors for precise CVD applications. The sublimation temperature must be preferably in the range 70,125 °C, and the decomposition temperature (substrate temperature) in the range of 350,400 °C. Three distinct regions can be recognized by heating: transformation of tightly bound water molecules into easily movable ones, sublimation of iodine ions and Co atoms oscillation and thermal decomposition of the glycositic ring into volatile by-products. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||