Prismane itself was first synthesized in 1973 by Katz and Acton. It is explosive but stable at room temperature. It slowly rearranges to benzen in solution at elevated temperature. All the hydrogens in prismane are equivalent and absorb upfield at d2.28 (benzene,d 7.33) in the 1H NMR spectrum while the carbons appear as a singlet at 30.6 ppm (benzene, 128.36 ppm) in the 13C spectrum. The large 13C-1H coupling constant (J = 180 Hz) argues that the tetrahedral geometry is greatly distorted. The 13C-1H coupling in methane is 125 Hz, where the sp3 hybridized carbon has 25% s character in the C-H bond. Accordingly, as the C-C-C bond angles are reduced in prismane and develop more p character, the C-H bond of prismane gains more s character and should be more acidic than methane.