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Cyclopentadienyl Complexes (cyclopentadienyl + complex)
Selected AbstractsChemInform Abstract: Structures, Preparation and Catalytic Activity of Ruthenium Cyclopentadienyl Complexes Based on Pyridyl-Phosphine Ligand.CHEMINFORM, Issue 7 2010Prashant Kumar Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Reaction of Nitrous Oxide with Cyclopentadienyl Complexes of Cobalt, Rhodium, and Titanium.CHEMINFORM, Issue 52 2001A. V. Leont'ev Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Highly Efficient Redox Isomerization of Allylic Alcohols at Ambient Temperature Catalyzed by Novel Ruthenium,Cyclopentadienyl Complexes,New Insight into the MechanismCHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2005Belén Martín-Matute Dr. Abstract A range of ruthenium cyclopentadienyl (Cp) complexes have been prepared and used for isomerization of allylic alcohols to the corresponding saturated carbonyl compounds. Complexes bearing CO ligands show higher activity than those with PPh3 ligands. The isomerization rate is highly affected by the substituents on the Cp ring. Tetra(phenyl)methyl-substituted catalysts rapidly isomerize allylic alcohols under very mild reaction conditions (ambient temperature) with short reaction times. Substituted allylic alcohols have been isomerized by employing Ru,Cp complexes. A study of the isomerization catalyzed by [Ru(Ph5Cp)(CO)2H] (14) indicates that the isomerization catalyzed by ruthenium hydrides partly follows a different mechanism than that of ruthenium halides activated by KOtBu. Furthermore, the lack of ketone exchange when the isomerization was performed in the presence of an unsaturated ketone (1 equiv), different from that obtained by dehydrogenation of the starting allylic alcohol, supports a mechanism in which the isomerization takes place within the coordination sphere of the ruthenium catalyst. [source] Design your own elastomeric or stereoregular polymer,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 10-12 2002Michal Shmulinson Abstract This study reports the synthesis and activity as precatalysts for the polymerization of propylene of five racemic group 4 complexes, cis-[p-R,C6H4C(NR)2]2MX2 (R,,=,CH3, R,=,SiMe3, M,=,Ti, X,=,Cl (1); R,,=,CH3, R,=,SiMe3, M,=,Zr, X,=,Cl (2); R,,=,H, R,=,i-pr, M,=,Zr, X,=,Cl (3); R,,=,CH3, R,=,SiMe3, M,=,Zr, X,=,CH3 (4)) and (acac)2MCl2 (M,=,Ti (5), M,=,Zr (6)) (acac,=,acetylacetone). The hydrocarbyl complex 4 was prepared by the alkylation of the corresponding complex 2 with MeLi·LiBr. Reaction of complex 4 with B(C6F5)3 or all complexes with MAO (MAO,=,methylalumoxane) results in the formation of a "cationic" intermediate complex which rapidly reacts with the incoming monomer. Some of the complexes catalyze the stereoregular polymerization of propylene only under pressure in either toluene or CH2Cl2, producing polypropylene with very large isotacticities (mmmm %,=,,95,98), high melting points (140,154,°C) and similar molecular weights as compared with cyclopentadienyl complexes, whereas complex 5 is active for the polymerization of elastomeric polypropylene. Copyright © 2003 John Wiley & Sons, Ltd. [source] | ||||||||||