SPIN-ECHO NMR STUDIES OF CHEMICAL EXCHANGE. VI. REARRANGEMENT OF BULLVALENE AND OF ITS AGN03 COMPLEX,
Abstract
The degenerate Cope rearrangement of bullvalene has been studied from 25 to 123C, in a tetrachloroethylene solution, by means of a spin-echo nmr method, at 26.85 Mc/sec. In effect, the inhomogeneity broadening of the nmr absorption is avoided in the spin-echo experiments so that exchange rates could be measured which were faster by a ten-fold factor than the upper limit in previous high-resolution work. More precise values were obtained for the frequency factor, 0.8 x 10 to the 13th power/sec, and for the activation energy, 12.8 = 0.1 kcal/mole. Bullvalene was found to form several complexes with AgN03 in D20 and in CH3CN solution, and with AgBF4 in CH2C1CH2C1. The rearrangement rates were reduced in these solutions. A 3:1 Ag+ to bullvalene system, 0.32 g in 7.15 M AgN03 in D20, was studied in some detail. For it, the apparent activation energy for the rearrangement is 15.1 = 0.8 kcal/mole. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 29, 1965
- Accession Number
- AD0616602
Entities
People
- Adam Allerhand
- Herbert S. Gutowsky
Organizations
- University of Illinois Urbana–Champaign