Rotationally fixed ferrocenophane extends the variety of possible molecular geometries in its derivatives in comparison with unbridged ferrocenes. In this respect molecular geometry-liquid crystalline properties relationship studies in ferrocenophane mesogens are of considerable interest. Different positional isomers of mono- and di-substituted ferrocenophanes which are obtained by incorporating one or two promesogenic building blocks into the cyclopentadienyl rings are reported in this article. A series of mono-substituted ferrocenophane-containing Schiff's bases was synthesized by condensing isomeric p-aminophenyl ferrocenophanes with appropriate aldehydes. Isomers of di-substituted ferrocenophane amines gave rise to a series of azomethines with two promesogenic substituents in the cyclopentadienyl rings. Besides, a β-enaminoketone was prepared from 3-(p-aminophenyl)ferrocenophane. Nematic and smectic mesophases were observed in the synthesized compounds under a polarizing optical microscope. The ferrocenophane-containing β-enaminoketone showed complex mesomorphic behaviour connected with occurrence of the keto-enamine and imino-enol tautomeric equilibrium in this compound. On the base of computational models obtained by semi-empirical quantum chemistry calculations the molecular geometry-phase behaviour relationships were examined. It was demonstrated that mesomorphism of ferocenophane azomethines depends on the spatial orientation of the substituents with respect to the propanediyl bridge in a case of mono-, and as well as to each other in a case of di-substituted derivatives.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry