High-Temperature Phase Transition in N(CH3)4CdCl3 Studied Using Static NMR and MAS NMR

To clarify the nature of microscopic structural changes of N(CH3)4CdCl3 at high temperatures, the nuclear magnetic resonance (NMR) spectra of the protons and carbons in N(CH3)4CdCl3 were measured. NMR studies of the 1H and 13C spin–lattice relaxation time, T1ρ, in the rotating frame were also performed. No changes in the T1ρ of 1H and 13C associated with the N(CH3)4 groups were observed at the high-temperature transition from phase I to phase I′. However, the 14N NMR spectra reflected changes in the structural geometry during the transition to phase I′, indicating that this transition is driven by N(CH3)4.