3d image of crownether skeletal formula

7-dithia-15-crown-5 crown ether cyclic oligomer compound application nomenclature organic synthesis complex structure name chemistry formation reaction chiral thia crystal preparation mechanism organic synthesis phase transfer catalysts ion-selective electrode complexing agent 3d rendering chemical biochemistry science scientific research biology atom molecule molecular structural formula skeletal geometry ball stick tautomer isomer stereoisomer orbital structure activity relationship sar substance matter material stuff component reagent functional group production macrocyclic heterocyclic heterocycle ring sulfur