Luminescent, liquid crystalline tris(N-salicylideneaniline)s: synthesis and characterization

A new class of discotics derived from tris(N-salicylideneaniline)s have been synthesized and their thermal and photophysical properties are investigated. These systems with outer 1,3,4-oxadiazole wings exist in an inseparable mixture of two keto-enamine tautomeric forms with C(3h) and C(s) rotational symmetries, and self-assemble into fluid columnar phase over a wide thermal range as evidenced by several complementary studies. They possess emissive characteristics in both solution and columnar states; the blue light (lambda = 474 nm) emission has been evidenced for the former state.