We have synthesized a new series of all-organic liquid crystalline (LC) radical compounds (2), which are the structural isomers of the previously reported series (1) containing a chiral nitroxide unit in the mesogen core. Only difference between the two isomers is the orientation in the ester functionality (-OCO- vs -COO-). The new LC compounds 2 with C4 to C8 alkoxy terminal chains showed the distinct odd-even effects of alkoxy terminal chains with respect to the thermal stability of nematic phases, while such effects were not observed for the isomers 1.