Symmetrical charge-localized intervalence (IV) compounds of the type M⁰-B-Mⁿ⁺¹ provide simple model systems for electron transfer.  These systems show a charge transfer (CT) band in the optical spectrum which corresponds to the transfer of an electron from one M group to the other.  Hush provided a way to determine the coupling constant, H_ab, using the parameters obtained from the CT band if the distance between the two M groups is known.  The remarkably simple Marcus-Hush two-state theory in which only the two charge-bearing units (CBU), M, are considered to possess charge works quite well for calculating the rate of electron transfer in many IV compounds.  However, when the bridge is low enough in energy the two-state model will break down because the bridge must be taken into account.  Herein, we present the study of a series of bishydrazines in which the bridge energy is lowered relative to the CBUs by elongating the bridge distance in order to determine the validity of the two-state Marcus-Hush theory in this regime.