  Two recent experimental (Li, J.~\emphj{et al}, \emph{Proc.\ Natl.\ Acad.\
Sci.\ U.~S.~A.} {\bf 2014}, 111, 1282-1287) and theoretical studies (B\^aldea,
I, \emph{Phys.\ Chem.\ Chem.\ Phys.}\ {\bf 2014}, 16, 25942-25949) have
addressed the problem of tuning molecular charge and vibrational properties of
single molecules embedded in nanojunctions. These are molecular characteristics
escaping so far to an efficient experimental control in broad ranges. Here, we
present a general argument demonstrating why, out of various experimental
platforms possible, those wherein active molecules are asymmetrically coupled
to electrodes are to be preferred to those symmetrically coupled for achieving
a(n almost) complete redox process, and why electrochemical environment has
advantages over "dry" setups. This study aims at helping to nanofabricate
molecular junctions using the most appropriate platforms enabling the broadest
possible bias-driven control of the redox state and vibrational modes of single
molecules linked to electrodes.

Chemical Physics;Mesoscale and Nanoscale Physics;Materials Science