Ionic metallomesogens derived from silver(I) bis-amine complexes: Structure and mesogenic behavior

Complexes [Ag(NH2R)2]X, (X = NO3, R = –C6H4–CnH2n+1-p, –C6H4–O–CnH2n+1-p, –CH2–C6H4–O–CnH2n+1-p, n = 6, 8, 10, 12, 14; X = BF4, R = –CH2–C6H4–O–CnH2n+1-p, n = 6, 8, 10, 12, 14; X = OAc, R = –CH2-C6H4–O–C10H21-p; X = CF3SO3, R = –CH2–C6H4–O–C10H21-p) have been prepared. They all show SA mesophases corresponding to two kinds of structures, already present in the solid state. The alkylaniline and alkoxyaniline derivatives adopt a bilayered structure where the cation has an extended centrosymmetric conformation. The benzylamine derivatives contain U-shaped cations giving rise to a bilayered structure which allows microsegregation of the organic part of the molecule from the inorganic Ag⋯(anion) part. Some degree of interdigitation of the terminal chains is observed for all the complexes with aryl containing ligands.

Complexes [Ag(NH2R)2]X derived from long chain substituted aromatic amines (anilines and benzylamines) form bilayered smectic A mesophases. Two different conformations are encountered for the cations depending on the amine ligand: U-shaped for the benzylamines, and extended centrosymmetric for the anilines. This difference has marked influence on the stability of the mesophase.Figure optionsDownload as PowerPoint slide