3d image of 12-crown-4 skeletal formula

12-crown-4 tetramer ethylene oxide ether methacryloyl chloride crown initio lithium cation organic chemistry ion synthesis dibenzo benzo complexes ball stick ionophore cyclic chemical compound oligomer complexing agent 3d rendering molecule molecular structural structure formula skeletal geometry substance reagent functional group iupac cas einecs macrocyclic heterocyclic heterocycle polycyclic ring