Abstract
The synthesis, characterization and mesogenic properties of Schiff base compounds arising from the reaction of 4‐alkoxybenzaldehydes with 4‐aminothiophenol or 4‐bromoaniline are described. Whereas the Schiff base thiol with two benzene rings in the molecule, HSC6H4NC(H)C6H4OC16H33 (2), is non‐mesogenic, the bromo analogue, BrC6H4NC(H)C6H4OC16H33 (3), is mesogenic. The introduction of a third benzene ring into the molecular architecture of 2 and 3 produced thiol‐ and bromo‐Schiff base compounds, HSC6H4NC(H)C6H4OC(O)C6H4OC16H33 and BrC6H4NC(H)C6H4OC(O)C6H4OC16H33, respectively, that are both mesogenic. The thiol compounds react with nickelocene to form [(η 5‐C5H5)Ni(μ 2‐SC6H4NC(H)C6H4OC16H33)]2 and [(η 5‐C5H5)Ni(μ 2‐SC6H4NC(H)C6H4OC(O)‐C6H4OC16H33)]2, but the nickel complexes are not mesogenic.
Acknowledgements
We thank Dr W. A. Ddamba, University of Botswana for some of the DSC data. We also thank the National Research Foundation (South Africa) for a postgraduate bursary (R.M.M.) and the University of the Western Cape (J.D.) for funding.