Rattling motion of proton through five membered aromatic ring systems

Abstract

We study the passage of proton (H+) through different five membered aromatic ring systems by considering one dimensional motion of the proton along a line perpendicular to the plane of the ring. The potential for the motion of (H+) from one side of the ring to the other through the center of the ring is found to be symmetric double well and such complexes are suggested as molecular rattles which can exhibit a ring umbrella like inversion. Our study reveals C2H2P3--H+ to be a molecular rattle with a barrier height of 1.91 eV and exciting it to the third vibrational level leads to an oscillation of proton through the ring.