Protonic conduction in imidazole: A solid-state N-15 NMR study

Reports of protonic conductivity in crystalline imidazole describe a pronou nced anisotropy in the transport of H+ with respect to crystallographic dir ection. Since charge is carried mainly along imidazole's hydrogen bonding a xis (c), it has long been hypothesized that the phenomenon involves the tun neling of protons through hydrogen bonds. A two-dimensional nitrogen-15 exc hange NMR study of N-15-labeled imidazole, however, demonstrates that the c onduction mechanism does not involve the reorientation of the imidazole rin g invoked in current models.