Syndiospecific polymerization of styrene. 3. Catalyst structure

Autor:	Sizhong Dong, James C. W. Chien, Zdenek Salajka
Rok vydání:	1992
Předmět:	Polymers and Plastics Chemistry Hydride Organic Chemistry Methylaluminoxane Catalysis law.invention Inorganic Chemistry Active center chemistry.chemical_compound Polymerization law Redox titration Polymer chemistry Materials Chemistry Ziegler–Natta catalyst Electron paramagnetic resonance
Zdroj:	Macromolecules. 25:3199-3203
ISSN:	1520-5835 0024-9297
DOI:	10.1021/ma00038a028
Popis:	The active oxidation state of Ti in the cyclopentadienyltributoxyltitanium methylaluminoxane (CpTi(OBu) 3 /MAO) catalyst has been determined by electron paramagnetic resonance (EPR) and redox titration. The results, together with previously reported active species concentrations measured by radiolabeling techniques, showed that all the catalytic species are trivalent Ti. The syndiospecific species (78% Ti) is characterized by a sharp EPR resonance at g=1.989 ( H a=7G) which corresponds to a titanium(III) hydride. The nonspecific species (13% Ti) has a g value at 1.995
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f851de0adf55fa5ed28cb811241d8f16 https://doi.org/10.1021/ma00038a028 Zobrazit plný text záznamu