Two homologous series of hydrogen bonded ferroelectric liquid crystal (HBFLC) series have been isolated. One mole of ferroelectric Dextro tartaric acid (DTA) is mixed with 2 mol of p-n-alkyloxy benzoic acid (BAO) to obtain homologues of DTA + nBAO. Eight mesogens are isolated by varying the carbon number from pentyloxy to dodecyloxy viz., DTA + 5BAO to DTA + 12BAO. Similarly 1 mol of ferroelectric Dextro tartaric acid (DTA) is mixed with 2 mol of p-n- alkyl benzoic acid (BA) to obtain homologues of DTA + nBA. Seven mesogens are isolated by varying the carbon number from pentyl to dodecyl viz., DTA + 3BA to DTA + 8BA. Spectroscopic characterization (FTIR, ¹H and ¹³CNMR) for all the 14 mesogens indicate the formation of hydrogen bond in HBFLC. Optical textures are recorded in various phases. An interesting observation is the finding of parachromatism in cholesteric phase. In addition to the conventional phases, two new smectic orderings viz., smectic X* and re-entrant smectic C* have been characterized. The textures of smectic X* exhibits a worm like textures while that of smectic C* is broken focal conic and the transition from smectic X* to re-entrant smectic C*. Smectic X* is observed to be sandwitched between cholestric and smectic C*. The x-ray study of smectic X* confirm it to be a smectic ordering. Measurments of tilt angle, light filtering and dielectric relaxation studies have been performed in this new smectic ordering. A new smectic ordering labeled as re-entrant smectic C* has been identified and characterized. Data of dielectric relaxation, magnitude of tilt angle in this phase confirm this phase is distinctly different from conventional smectic C*. Re entrant Smectic C* and Smectic X* are observed in higher homologues of DTA + nBAO where ‘n’ varies from 8 to 12.

氢键铁电液晶（HBFLC）系列的两个同源系列已被隔离。将一摩尔铁电右旋酒石酸（DTA）与2摩尔的pn-烷氧基苯甲酸（BAO）混合以获得DTA + nBAO的同系物。通过改变碳原子数，从戊氧基到十二烷氧基，即DTA + 5BAO到DTA + 12BAO，分离出八个液晶元。类似地，将1摩尔铁电右旋酒石酸（DTA）与2摩尔pn烷基苯甲酸（BA）混合以获得DTA + nBA的同系物。通过改变碳原子数从戊基到十二烷基，即DTA + 3BA到DTA + 8BA，可以分离出七个液晶元。光谱表征（FTIR，¹ H和¹³所有14个液晶元的CNMR都表明在HBFLC中形成了氢键。在各个阶段记录光学纹理。一个有趣的发现是在胆甾相期发现了超铬铁症。除常规阶段外，还对两个新的近晶顺序进行了表征，即近晶X *和折返近晶C *。近晶X *的纹理表现出蠕虫状的纹理，而近晶C *的纹理则是破碎的圆锥形，并且从近晶X *转变为折返近晶C *。观察到近晶X *在胆囊C *和近晶C *之间被wit住了。近晶X *的X射线研究证实它是近晶顺序。倾斜角的测量，滤光和介电弛豫研究已在这种新的近晶排列中进行。一个新的近晶顺序被标记为可重入近晶C *，并已被鉴定和表征。该阶段的介电弛豫数据，倾斜角度的大小证实了该阶段与常规近晶C *明显不同。在DTA + nBAO的较高同源物中观察到重入的近晶C *和近晶X *，其中'n'在8到12之间变化。