We have explored the formation of an R(4)N-metal derived from n-methylquinuclidinium (MQ(+)) and mercury cathode. For each MQ(+) cation, 5 Hg atoms are consumed and the stoichiometric composition of electrodeposited MQ-mercury is MQ(Hg-5). The early stages of an MQ(Hg-5) deposition were investigated by cyclic voltammetry and potential step chronoamperometry. The first process is the deposition of an initial layer which is controlled by two-dimensional nucleation and growth kinetics. Deposition of the bulk phase is initiated by a three-dimensional nucleation and growth controlled by diffusion of MQ(+) from the solution. A significant difference in the catalytic properties of the initial layer and the bulk phase is identified showing that the initial layer transfers electrons to organic substrates more efficiently and is a better catalyst.