ChemInform Abstract: Multifunctional Tetracoordinate Phosphorus Species with High Self-Organizing Ability

Abstract

Abstract The unique features of the phosphonium salts as functional materials are reviewed, with emphasis being placed on the comparison between the phosphonium salts and the commonly available quaternary ammonium salts, which have the same structure, differing only in the positively-charged heteroatom. The antimicrobial activity of onium salts with different long-chain segments is described with special reference to structure–activity relationships. The unexpected relationship between the antibacterial activity and the aggregation behavior in aqueous solution (i.e. lyotropic liquid-crystalline properties) was revealed through systematic studies on the antibacterial activity of the phosphonium salts as a novel class of cationic biocides. Furthermore, it is shown that the phosphonium salts can act as thermotropic liquid crystals in spite of the fact that they are amphiphiles without a rigid core.