Nematic liquid-crystal phases doped with the novel dopant compounds 1 (C6F5COO(CH)(n)OCOC6F5, n = 1-7) and 2 (C6H5COO(CH)(n)OCOC6H5, n = 1-7) showed an "opposite odd-even effect" on clearing temperatures. The tendency was exactly opposite to that reported for liquid-crystal dimers. A mechanism is postulated on the basis of the difference in the formation of molecular aggregations of even- and odd-number-dopant molecules in the host liquid-crystal molecules.