Mesomorphism of complexed 2,6‐disubstituted pyridine ligands: crystal and molecular structure of two bent‐core pyridines

Abstract

Bent‐core, polycatenar pyridines are reported, synthesized via a Siegrist coupling of di‐ and tri‐alkoxybenzylidene fragments with 2,6‐dimethylpyridine. None of these pyridines was liquid crystalline. Isomeric materials based on a 3,5‐disubstituted pyridine core were mesomorphic in hydrogen‐bonded complexes, whereas these new materials were not. However, the new pyridines did form mesomorphic metal complexes with silver salts. Some insight into this behaviour is gleaned from single crystal structure determinations of the model systems, 3,5‐bis(3′,4′‐dimethoxystyryl)pyridine and 2,6‐bis(3′,4′‐dimethoxystyryl)pyridine.

Acknowledgements

This work was supported by Comunidad de Madrid, by contract No. GR/MAT/0511/2004 and by a postdoctoral fellowship (M.C.T.), by the UK EPSRC (D.M.H. and H.L.N.) and by the Collège Doctoral Européan de Strasbourg (D.M.H.). Helpful discussions with Dr Daniel Guillon (IPCMS, Strasbourg) are acknowledged gratefully.