Exciplex formation between several unlinked donor-acceptor systems has been studied in benzene, toluene and p-xylene solvents. It has been found that for small planar molecules the exciplex stability increases with increase in the solvent bulk. It has been concluded that an optimum distance between the donor and acceptor is of paramount importance for exciplex stability and this distance can be modulated by the intervening solvent medium. (C) 2003 Elsevier Science B.V. All rights reserved.