Proton Magnetic Resonance Spectrum of Propane

Abstract

Exact protonmagnetic resonance eigenspectra of the spin Hamiltonian are calculated for a system containing one group of six identical protons and one group of two identical protons. The method of calculation considers each group of identical protons as a composite ``particle'' with fixed total spin, and does not require determination of the explicit form of the zero‐order eigenfunctions. The calculated spectra are compared with experimental high‐resolution spectra of propane at both 40 Mc and 60 Mc. Thevalues of p, the ratio of the spin coupling constant to the chemical shift, are found to be 0.415 and 0.277, respectively, at the two frequencies. The frequency‐independent spin coupling constant is 7.26 cps.