A derivative of dibenzo-18-crown-6 containing dihydroxyphosphorylmethy
l groups in the 4, 5, 4', and 5' positions of the benzene ring has bee
n synthesized. Unlike dibenzo-18-crown-6, its phosphorylated derivativ
e does not form stable complexes with cations of alkali and alkaline-e
arth metals. Complexes with transition metals are water-insoluble in m
ost cases.