Synthesis and characterization of weakly coordinating anion salts of a new, stable carbocationic reagent, the dibenzosuberenyl (dibenzotropylium) ion

Cordoneanu, A; Drewitt, MJ; Bavarian, N; Baird, MC

HERO ID

3860755

Reference Type

Journal Article

Year

2008

HERO ID 3860755
In Press No
Year 2008
Title Synthesis and characterization of weakly coordinating anion salts of a new, stable carbocationic reagent, the dibenzosuberenyl (dibenzotropylium) ion
Authors Cordoneanu, A; Drewitt, MJ; Bavarian, N; Baird, MC
Journal New Journal of Chemistry
Volume 32
Issue 11
Page Numbers 1890-1898
Abstract The new, bright red compounds [DBS][B(C(6)F(5))(4)], [DBS][BCl(C(6)F(5))(3)], [DBS][B(C(6)F(5))3-OH center dot center dot center dot H(2)O-B(C(6)F(5))(3)] and [DBS][B(CH(2)CMe(3))(C(6)F(5))(3)] (DBS = C(15)H(11), dibenzosuberenyl, dibenzotropylium, dibenzo[a, e] tropylium or dibenzo[a, d] cycloheptenocarbonium) have been synthesized and characterized spectroscopically and, except for [DBS][B(CH(2)CMe(3))(C(6)F(5))(3)], crystallographically. The crystal structures show that the DBS(+) carbocation is planar and suggest pronounced delocalization of the positive charge over part of the seven-membered ring, in particular the CH carbon and the carbon atoms alpha and beta to it. The electrophilic DBS(+) carbocation activates alkene polymerization catalyst precursors of the type Cp'(2)ZrMe(2), its efficacy being comparable to that of the well known but sterically more hindered trityl carbocation, Ph(3)C(+). As with the Ph(3)C(+) ion, DBS(+) does not initiate carbocationic polymerization of isobutene in dichloromethane directly, but rather by reacting with trace amounts of water to generate protons.
Doi 10.1039/b804868a
Wosid WOS:000261746000009
Is Certified Translation No
Dupe Override No
Is Public Yes