A new series of mesomorphic complexes formed through intermolecular hydroge
n bonding between p-n-alkoxybenzoic acids (where alkoxy denotes chains from
propoxy- to decyloxy- and dodecyloxy-) and non-mesogenic p-hydroxybutyl be
nzoate, have been synthesized and characterized by thermal microscopy, diff
erential scanning calorimetry, infrared spectroscopy (IR) and H-1 NMR studi
es. A detailed IR spectral investigation in the solid state and in solution
suggests that the acid and phenol groups are complementary to each other,
each acting as both proton donor and proton acceptor. The results of compar
ative thermal analyses of both free p-n-alkoxybenzoic acids and H-bonded co
mplexes exhibited an induced crystal smectic G phase in the complexes throu
ghout the series, its thermal range increasing with alkoxy carbon number.