Synthesis, Crystal Structure and properties of N,N-Dimethyl-N-(6-(benzoyl-4-phenoxy)hexamethylen)-N-n-dodecyl-ammonium bromide: a new substantive UV filter.

Inprevious paper we have described the synthesis, the substantivity and the antibacterial activity of 4-hydroxy and 2,4-dihydroxy benzophenone derivatives. These properties were affected by the lenght of the n-alkyl chain bonded to the quaternary nitrogen. It would have been of interest to take into consideration also the effect on these properties of the lenght to the methylene chain connecting the oxygen and quaternary nitrogen atoms. In this view we have synthesized N,N-dimethyl-N-(6-(benzoyl-4-phenoxy)hexamethylen)-N-n-dodecil ammonium bromide. Substantivity and antimicrobial properties of this compound have been evaluated and the conformation in the solid state has been determined by single crystal X-ray diffraction. The conformation of the molecule which has been shown to play a fondamental role for the antibacterial activity of these compounds presents an extensive folding of the n-dodecyl chain back towards and along the aromatic moiety. Coiled conformations that have been associated with antibacterial properties and skin irritation phenomena are absent.