Organic film stable complexes

The participation of hydride species in this process is corroborated by the ability of complexes [( 75-C5Me5)RhIII(bpy)Cl]+ (M = Rh or Ir)28 and [Rhni(bpy)(PPh2Et)2(Cl)2]+32 in films to perform ECH of organics. Indeed, such complexes are readily transformed to hydride derivatives upon electroreduction in protic electrolytes (see Section 9.10.3.1.1). However, these complexes give more stable hydride species and are much less active than [Rh(bpy)2(Cl)2]+ complexes. 

SA monolayers spontaneously form, by definition, upon the immersion of a substrate into an organic solution of a suitable surfactant. The method is attractive since it avoids the complex mechanical manipulation required for making LB films and it is amenable, at least in principle, to scale-up. Conditions for the reproducible formation of highly ordered, well-packed, and stable monolayers and multilayers have only been established during the last decade. 

More complex with respect to molecular interaction is the case of formation of non-aqueous films on the surface of aqueous solutions from non-ionic surfactants [528], Films from octane were obtained by adsorption from drops of octane/non-adsorbing diluent (squalane) mixture. Occasionally the spreading of alkanes on aqueous surfactant solution gives stable thin oil films (e.g. on solutions of the anionic surfactants Aerosol OT) [529,530], Some evidence about the stability of asymmetric films can be derived from the data about the surface pressure and spreading coefficients of liquids on water surface. These data are known for many organic liquids [531,532], It should be also noted that the techniques for determination of the spreading coefficients have improved considerably [533,534]. Most precise values were obtained by measuring the surface pressure of a monolayer with a special substance introduced as an indicator [533]. 

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