New crystalline complex chlorides containing transition metal chlorides or oxychlorides as components of coordination catalysts

Abstract

SynopsisNovel complex chlorides have been obtained by reacting TiC14, VOC13, MoOC14, WOC14, or AlC13 with Be, Mg, Ca, or Sr chlorides in the presence of electron donors such as POC13 (L) or C&,POC12(L'). The resulting products, obtained with good yield, show defined stoichiometry, ionic character, and crystalline structure, and may be considered reference systems for high-yield catalysts in the low-pressure polymerization of ethylene (HDPE). Complexes (TiCk)MgL6, (TiC1.&')2MgL'6, and (Ti&llo)MgL6 associated with (i-C4H&41 were found very active in HDPE synthesis, but completely unable to polymerize propylene. This result and other evidence suggest that part of the catalytic activity of these systems is displayed by soluble species. The role played by the Mg ion in high-yield catalysts is discussed in the light of the peculiar behavior shown by the complex chlorides containing this earth-alkali metal.

Incorporation of Ziegler–Natta catalyst components. Structures and reactivity of the intermediates

“…11 For propylene polymerization aromatic esters such as ethyl benzoate, ethyl anisate, and diisobutyl phthalate are often used. 12 Others include ethyl acetate, 13 ethyl chloroacetate, 14 phosphorus oxychloride, 15 and silanes. All these ligands form a family of moderately weak Lewis bases and establish good leaving groups.…”