A catalytic multiple-proton/hydrogen atom relay in the 7-azaindole-methanol cluster (7AI(MeOH)(n), n = 1-3) has been investigated in the gas phase by measuring the mass-resolved vibronic spectra and the dispersed fluorescence spectra of AI(MeOH)(n), (n = 1-3). It has been found that the observation of the visible fluorescence due to the multiple-proton/hydrogen atom relay is cluster-size selective; 7AI(McOH)2 undergoes an efficient triple-proton/hydrogen atom relay on a pi pi* and/or pi sigma* surface. The triple-proton/hydrogen atom relay in this cluster also exhibits prominent vibrational-mode selectivity. The excitation of an intermolecular stretch mode (sigma(1)) with the in-phase cooperative motion of the whole hydrogen-bond network accelerates the proton/hydrogen atom relay. (c) 2006 Elsevier B.V. All rights reserved.