Formation of columnar hexagonal mesophases near room temperature from functionalised [9]aneNS2 (1,4-dithia-7-azacyclononane)

Oligo(benzoate) derivatives, (R)[9]aneNS(2), of 1,4-dithia-7-azacyclononane [R = OC-C6H4-4-OR' (1) [R' = C3H7 (a) C8H17 (b)], OC-C6H4-4-O2C-C6H4-4-OC8H17 (2), OC-C6H4-4-O2C-C6H4-4-O2C-Z, Z = C6H4-4-OC8H17 (3), C6H3-3,4-(OR'(2))(2) (4) [R' = C4H9 (a), C8H17 (b), C12H25 (c)], C6H2-3,4,5-(OC12H25)(3) (5)] have been synthesised. Compound 3 displays monotropic nematic and smectic phases, while 5 shows an enantiotropic columnar hexagonal phase (Col(h)) just above room temperature as characterised by X-ray scattering experiments. Dilatometry suggests a model for the packing of molecules of 5 in the mesophase. An alternative route to these compounds has been developed via the preparation of the protected species 6 [R = OC-C6H4-4-OC(O)OMe], which can be deprotected using aqueous NH3 to give 7 [R = OC-C6H4-4-OH], followed by reaction with the appropriate acid chloride or anhydride. Oligo(benzoate) derivatives, (R)(2)[9]aneN(2)S, of 1-thia-4,7-diazacyclononane [R = OC-C6H4-4-OC(O)OMe (8), OC-C6H4-4-OH (9) OC-C6H4-4-O2C-C6H4-4-OC8H17 (10), OC-C6H4-4-O2C-C6H2-3,4,5-(OC12H25)(3) (11)] have been prepared as transesterification products.