Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens
- Sonja Findeisen-Tandel,
- Wolfgang Weissflog,
- Ute Baumeister,
- Gerhard Pelzl,
- H. N. Shreenivasa Murthy and
- Channabasaveshwar V. Yelamaggad
Beilstein J. Org. Chem. 2012, 8, 129–154, doi:10.3762/bjoc.8.15
Graphical Abstract
Scheme 1: Examples for bent mesogens containing salicylideneimine moieties.
Scheme 2: Synthetic pathway to prepare compounds OH 1.
Figure 1: Polarising optical microscopy images. a) Compound OH 1a: Grainy texture with smectic Schlieren area...
Figure 2: X-ray diffraction pattern of a powderlike sample of OH 1b at 131 °C (inset: Small angle region; low...
Figure 3: Electro-optical behaviour of compound OH 1a: a) current response curve (U = 182 Vpp, f = 30 Hz, T =...
Figure 4: Switching behaviour of compound H 1a, which depends on how quickly the electric field is switched o...
Scheme 3: Reaction pathways to prepare the monosalicylideneaniline compounds OH 2a–j.
Figure 5: Compound OH 2a: Texture of the SmCP phase at 126 °C.
Figure 6: a) 2D X-ray pattern of a surface-aligned sample of compound OH 2a at 128 °C (lower part of the patt...
Figure 7: Electro-optical switching behaviour of compound OH 2a: a) current response (U = 230 Vpp, f = 25 Hz, ...
Scheme 4: Synthetic steps followed to prepare the compounds OH 3 and OH 4.
Figure 8: Optical photomicrographs of compound OH 3a: a) On cooling of the isotropic liquid; c) U = 0 V; b) U...
Figure 9: Electro-optical behaviour of compound OH 3a: a) Current response curve (U = 308 Vpp, f = 35 Hz, T =...
Figure 10: Growth of a fan-shaped texture from lancetlike filaments upon cooling of the isotropic liquid of co...
Figure 11: a) 2D X-ray pattern of a surface-aligned sample of compound OH 3b at 160 °C (lower part of the patt...
Figure 12: Compound OH 3b: Texture of the SmCPA phase in dependence on the polarity of the applied D.C. field.
Figure 13: Compound OH 4b, exhibiting a fan-shaped texture together with a Schlieren texture upon cooling of t...
Figure 14: 2D X-ray diffraction pattern of a partially surface-aligned sample of OH 4b at 115 °C (inset: Small...
Figure 15: Switching behaviour of compound OH 4b at 120 °C: a) Current response curve (U = 116 Vpp, f = 40 Hz, ...
Figure 16: Compound OH 4d: a) Microphotograph of a growing fringe pattern of a SmCP phase upon cooling of the ...
Figure 17: Electro-optical behaviour observed on the fan-shaped texture of compound OH 4d; UD.C. = 47 V; T = 1...
Figure 18: a) 2D X-ray diffraction pattern for a surface-aligned sample of OH 4d at 122 °C on cooling; b) χ-sc...
Scheme 5: Reaction steps employed for the preparation of the compounds OH 5 and OH 6.
Figure 19: Compound OH 5d: Optical photomicrographs of chiral domains at 122 °C; polariser and analyser are un...
Figure 20: Compound OH 5b: a), b) Chiral domains at 175 °C, 0 V, polarisers uncrossed by about ±8° from the 90...
Figure 21: X-ray diffraction patterns of compounds OH 5: a) Pattern of a powderlike sample of compound OH 5g a...
Figure 22: Photomicrographs of compound OH 5f: a) Appearance of spiral filaments on slow cooling of the isotro...
Figure 23: Current response of compound OH 6b exhibiting two repolarisation peaks proving an antiferroelectric...
Figure 24: On cooling the isotropic liquid phase of compound OH 6c; a Schlieren texture together with fringe p...
Figure 25: Electro-optical behaviour of compound OH 6c: a) Current response (UA.C. = 17 V/µm, f = 39 Hz, T = 1...
