Quantitative relation between surface active properties and antifungal activity of quaternary imidazolium chlorides (new wood preservatives)

1-Alkyl-3-benzyloxymethylimidazolium, 3-alkoxymethyl-1-benzylimidazolium, 1-Alkyl-3-(3-phenylpropoxymethyl)imidazolium and 3-alkoxymethyl-1-decylimidazolium chlorides were prepared in very good yields. The critical micelle concentration values of the new heterocyclic chlorides by means of surface tension isotherms at 22±1 °C were determined and their hydrophobicity indices were calculated. All the chlorides examined showed antifungal activity against Coniophora puteana (Schum.:Fr.) Karst., Trametes versicolor (L.:Fr.) Pilat and Chaetomium globosum (Kunze:Fr.) by the agar-malt test method. The fungicidal value of the imidazolium chlorides was examined in a softwood (Pinus sylvestris L.) and a hardwood (Fagus silvatica L.) using an agar-block screening method. It was stated that the antifungal and surface active properties of the new chlorides depend upon the alkyl chain length in the imidazolium ring. The presented results demonstrate the quantitative relationship between the effective dose (ED50), the lethal dose (LD), the fungicidal value, and the critical micelle concentration, as well as the hydrophobicity of new quaternary imidazolium chlorides.