<p>Interesting mesogens of hydrogen bond liquid crystals (HBLCs) have been reported. Chloro per benzoic acid (ClPBAO) and alkyloxy benzoic acid (nBAO) are chemically treated to form a hydrogen bond. Eight homologues of this series are obtained by altering the methyloxy group from pentyloxy to dodecyloxy. A complementary hydrogen bonding occurs between proton donor of Hydroxyl group(–OH) and electron acceptor of Carbonyl group(–COOH) of ClPBAO and nBAO complexes; this causes forming a strong and stable HBLCs. Thermal and optical characterization of the thermotropic mesogenic phases of various homologues is carried out. From thermal characterization, <i>T</i>_c temperature and Δ<i>H</i> values are elucidated, and from optical microscopic characterization, textural observations are recorded. FTIR studies revealed the formation of the hydrogen bond. Optical modulation studies and light filtering action are discussed in detail.</p> Graphical abstract <p></p>