Large, Concentration-dependent Enhancement of the Quadratic Hyperpolarizability of [Zn(CH3CO2)2(L)2] in CHCl3 on Substitution of Acetate by Triflate

An unexpected dependence on concentration was found for the quadratic hyperpolarizability β of Zn complexes with stilbazole and CF3SO3-ligands (see values given), which reaches very large values on dilution. This is surprising, because the concentration used for determining β is traditionally not given in the literature, probably because it is a molecular property that should not vary with concentration. The origin of this effect is also reported.