640270-82-2Relevant articles and documents
Isobutene Polymerization Using a Chelating Diborane Co-Initiator
Lewis, Stewart P.,Taylor, Nicholas J.,Piers, Warren E.,Collins, Scott
, p. 14686 - 14687 (2007/10/03)
Lewis acidic diborane 1 (J. Am. Chem. Soc. 1999, 121, 3244?3245) is highly effective for both proton- and cationogen-initiated isobutene polymerization in hydrocarbon media at low temperature. Reactions of diborane 1 with cumyl chloride and cumyl methyl ether were studied by variable-temperature 1H and 19F NMR spectroscopy. At low temperatures stable ion pairs 2a and 2b are formed; at higher temperatures these ion-pairs form phenyl-1,3,3-trimethylindan (3) with concomitant release of HCl to form 1 in the case of 2a or degradation of the anion (2b). Reaction between Ph3C-Cl and diborane 1 resulted in the generation of an ion-pair 4 consisting of the Ph3C cation very weakly associated with the chelated, μ-Cl counteranion as revealed by X-ray crystallography. Copyright