Multiple-quantum NMR in solids

Abstract

Multiple‐quantum NMR has typically been observed in small groups of spins in isolated molecules. Due to the profusion of spin transitions in a solid, individual lines are unresolved. Excitation of high quantum transitions by normal schemes is thus difficult. To ensure that overlapping lines add constructively and to enhance sensitivity, time‐reversal pulse sequences are used to generate all lines in phase. Up to 22‐quantum ¹H absorption in solid adamantane is observed.