Zh. Chen et Ra. Sachleben, CONFORMATIONAL-ANALYSIS OF SUBSTITUTED DIBENZO-14-CROWN-4 ETHERS IN SOLUTION BY 1D AND 2D NMR, Journal of inclusion phenomena and molecular recognition in chemistry, 16(1), 1993, pp. 91-95
The preferred conformations in solution for substituents on sym-dibenz
o-14-crown-4 ethers are shown by NMR to depend on the atom, carbon or
oxygen, linking the substituent to the crown ring.