The use of variable temperature 77Se NMR to determine the conformational changes in 2,11-diselena[3.3]metacyclophane

Abstract Low temperature 77 Se and 1 H nmr spectra clearly indicate that 2,11-Diselena [3.3]metacyclophane undergoes syn , anti interconversion with ΔG ≠ of about 8 kcal/mol. The bridge wobble also takes place, but with lower ΔG ≠ than could be measured unlike [3.3]metacyclophane itself.