Structure Studies on 6a‐Thiathiophthenes and Related Compounds

Abstract

AbstractThe results from structure studies on 6a‐thiathiophthenes show that different substituent groups perturb the bonding in the three‐sulphur sequence to different degrees. Both equal and unequal SS bonds occur in symmetrically as well as in unsymmetrically substituted derivatives.The specific effect of methyl and phenyl substituents on the sulphur‐sulphur bonding may be described by the results from CNDO/2 calculations on mono‐methyl and mono‐phenyl substituted 6a‐thiathiophthenes. Molecular packing and intermolecular close contacts also seem to affect the SS bonding.The structures of equally substituted 6a‐thiathiophthene analogues with magnified image and magnified image show, when compared with the equivalent 6a‐thiathiophthene, that magnified image and magnified image cause a pronounced change in the SS bonding, while the perturbation caused by magnified image is negligible.In symmetrical 6a‐thiathiophthene analogues with magnified image and magnified image, the average bond length in the linear three‐atom sequence is 9 – 12% longer than the respective single bond.