Abstract: A stable solution of molecular material includes a first type of organic or organometallic molecule and a second type of organic or organometallic molecule or of ion. The first type has groups allowing electron delocalization. The solution further includes a third type of molecule that may be a surfactant or a solvent, capable of combining with the first or the second type of molecule or of ion), to form an adduct in solution whose presence prevents the precipitation of a compound formed by reaction between the first and second types of molecules, and makes it possible to obtain solutions whose concentration of the compound is greater than that governed by the precipitation constant of the compound in the absence of molecules of the third type.