A racemic or optically active crown ether compound having the formula ##STR10## wherein A and B, which can be the same or different, are hydrogen, straight chain or branched alkyl having from 1 to 6 carbon atoms, aryl having from 6 to 10 carbon atoms, or aralkyl having from 7 to 9 carbon atoms,
- R.sub.1 is hydrogen or straight chain or branched alkyl having from 1 to 20 carbon atoms, wherein R.sub.1 can be bonded to any carbon atom on the cyclic polyether and the number of R.sub.1 groups is from 1 to 12, n is an integer of from 3 to 10, and
- R.sub.4 and R.sub.5 are straight-chain or branched alkyl having from 4 to 30 carbon atoms.