41902-42-5Relevant articles and documents
Templating Influence of Molecular Precursors on Pr(OH)3 Nanostructures
Hemmer, Eva,Cavelius, Christian,Huch, Volker,Mathur, Sanjay
, p. 6267 - 6280 (2015/07/15)
Four new praseodymium alkoxo and amido compounds ([Pr3(μ3-OtBu)2(μ2-OtBu)3(OtBu)4(HOtBu)2] (1), [Pr{OC(tBu)3}3(THF)] (2), [PrCl{N(SiMe3)2}2(THF)]2 (3), and [PrCl{OC(tBu)3}2(THF)]2 (4)) were synthesized and structurally characterized by single-crystal X-ray diffraction analysis. Application of these compounds in solvothermal synthesis of praseodymium oxide/hydroxide nanostructures showed their templating influence on the morphology and phase composition of the resulting solid-state materials. Differential reactivity of the chosen alkoxide ligands toward water and the different arrangements of metal-oxygen units in the studied precursor compounds strongly influenced the kinetics of hydrolysis and cross-condensation reactions as manifested in the morphological changes and phase composition of the final products. Thermal decomposition studies of 1-4 confirmed their conversion into the corresponding oxide phases. Activation of compounds 1, 2, and 4 by either a base or a stoichiometric amount of water showed the distinct influence of their chemical configuration on the obtained nanopowders: whereas 1 solely produced nanorods of Pr(OH)3, 2 predominantly formed a mixture of rod-shaped and spherical particles. The solvothermal decomposition of 4 resulted in Pr(OH)2Cl or PrOCl due to the presence of Cl ligands in the molecular precursor. The resultant materials were thoroughly characterized to demonstrate the relationship between precursor chemistry and the processing parameters that are clearly manifested in the morphology and phase of the final ceramics. (Chemical Equation Presented).
Complexes of the Lanthanides, I. - Solvent-Free Alkoxide Complexes of Neodynium and Dysprosium. Crystal and Molecular Structure of trans-Bis(acetonitrile)tris(tri-tert-butylmethoxy)neodynium
Herrmann, Wolfgang A.,Anwander, Reiner,Kleine, Matthias,Scherer, Wolfgang
, p. 1969 - 1980 (2007/10/02)
The first lanthanide complex 3a is obtained from the sterically demanding silanol (tC4H9)3SiOH ("silox", 1a) and Nd2>3 (2a).Similarly, the bulky alcohols "tritox-H", tri-tert-butylmethanol (1b), and "ditox-H", di-tert-butylmethanol (1c), react with 2a to give the corresponding alkoxide complexes Nd(tritox)3 (3b) and 2 (3c), respectively.Under the same conditions Dy2>3 (2b) yields the homoleptic ditox derivative 6.The new complexes are all very soluble in aliphatic hydrocarbons.They show a very different thermal stability as, for example, expressed in their sublimation behaviour. Key Words: Lanthanide alkoxides, siloxides / Neodynium complexes / Dysprosium complexes / Thermochemistry
Olefins from Crowded Carbonyl Compounds with tert-Butyllithium (tert-Butylmagnesium Chloride)/Thionyl Chloride. Study of Carbocationic Reaction Intermediates and Rearrangement-Cleavage under Stable Ion Conditions Using 13C NMR Spectroscopy
Olah, George A.,Wu, An-hsiang,Farooq, Omar,Prakash, G. K. Surya
, p. 1792 - 1796 (2007/10/02)
Crowded carbonyl compounds when reacted with tert-butyllithium or tert-butylmagnesium chloride followed by thionyl chloride treatment give in an one-pot reaction olefins in good to excellent yields.In the case of highly crowded tertiary systems the reaction occurs either by rearrangement followed by the loss of a tert-butyl group (as isobutylene) or rearrangement accompanied by deprotonation, indicating the carbocationic nature of the process.The nature of the intermediate carbocation and their cleavage-rearrangement process was probed in SbF5/SO2ClF solution of thecorresponding alcohols under stable ion conditions using 13C NMR spectroscopy.
