Chapter 24: Problem 50
The \(50-\mathrm{MHz}{ }^{13} \mathrm{C}\) NMR spectrum of the 2 -norbornyl cation in \(\mathrm{SbF}_{5} / \mathrm{SO}_{2} \mathrm{ClF} / \mathrm{SO}_{2} \mathrm{~F}_{2}\) solution exhibits an interesting temperature dependence. At \(-159{ }^{\circ} \mathrm{C}\), the spectrum consists of five lines at \(\delta 20.4[\mathrm{C}(5)], 21.2[\mathrm{C}(6)]\), \(36.3[\mathrm{C}(3)\) and \(\mathrm{C}(7)], 37.7[\mathrm{C}(4)]\), and \(124.5[\mathrm{C}(1)\) and \(\mathrm{C}(2)]\). However, at \(-80^{\circ} \mathrm{C}\), the spectrum consists of three lines at \(\delta 30.8[\mathrm{C}(3), \mathrm{C}(5)\), and \(\mathrm{C}(7)], 37.7[\mathrm{C}(4)]\), and \(91.7\) \([\mathrm{C}(1), \mathrm{C}(2)\), and \(\mathrm{C}(6)]\) ppm. Explain. Hint: Start with the low- temperature spectrum.
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.