Scan Science and Technology
Contact Leading Edge Experts & Companies
The Experts below are selected from a list of 6960 Experts worldwide ranked by ideXlab platform
Hugo F Franzen – One of the best experts on this subject based on the ideXlab platform.
the structural phase transition in calcium Aluminum Compound caal4 a concerted application of landau theory and energy band theoryJournal of the American Chemical Society, 1993Co-Authors: Gordon J Miller, Fan Li, Hugo F FranzenAbstract:
CaAl[sub 4] undergoes a reversible, structural transformation at 170[degrees]C according to high-temperature X-ray powder diffraction experiments. The high-temperature phase adopts the tetragonal BaAl[sub 4] structure (space group I4/mmm), while the low-temperature phase is monoclinic, C2/m, with lattice parameters, a = 6.1526 (15) [angstrom], b = 6.1730 (13) [angstrom], c = 6.3290 (14) [angstrom], [beta] = 118.026 (16). The Landau theory of phase transitions correctly provided a structural model for the low-temperature phase, which could be subsequently refined. Also, electronic structure calculations on both forms of CaAl[sub 4] allow rationalization of the transformation in terms of changes in local chemical bonding within the Al framework. 26 refs., 8 figs., 8 tabs.
Tomoaki Matsugi – One of the best experts on this subject based on the ideXlab platform.
Direct Incorporation of Hydroxy Groups into Isotactic Polypropylene via Metallocene-Catalyzed Copolymerization of Ester Group Containing Vinyl Monomer Treated with DialkylAluminum Hydride and PropyleneBulletin of the Chemical Society of Japan, 2015Co-Authors: Ryuichi Sugimoto, Tomoaki MatsugiAbstract:
Methyl 10-undecenoate treated with 2 equivalents of diisobutylAluminum hydride was quantitatively converted into a 10-undecenoxy Aluminum Compound, which was successfully utilized for metallocene-c…
Hans Pritzkow – One of the best experts on this subject based on the ideXlab platform.
synthesis of main group and transition metal complexes with the 8 quinolyl cyclopentadienyl ligand and their application in the polymerization of ethyleneOrganometallics, 2004Co-Authors: Markus Enders, Gerald Kohl, Hans PritzkowAbstract:
Nucleophilic addition of 8-lithioquinoline to the Cp2Co+ cation leads to the formation of η4-(8-quinolylcyclopentadiene)(η5-cyclopentadienyl)cobalt(I) (7). Oxidative decomplexation with FeCl3 liberates the quinolyl-substituted cyclopentadiene derivative 2a, which is stable at low temperature only. Deprotonation by strong bases such as NaH or KH leads to the alkali metal quinolyl cyclopentadienide salts, which are used as precursors for the synthesis of the corresponding Ti, Cr, and Al complexes. Whereas after its activation the Aluminum Compound 13 does not yield an olefin polymerization catalyst, the chromium(III) complex 12 reacts with methylaluminoxane (MAO) to give a highly active catalyst for the polymerization of ethylene.