Crystal structure of 6-oxa-3,9-dithiabicyclo[9.2.2]pentadeca-1(15),11,13-triene.

The structure of an S2O mixed-donor macrocycle incorporating para-substituted xylyl subunit was characterized by a single crystal X-ray analysis. The crystal structure shows an exo-dentate orientation of sulfur and oxygen donor atoms due to the fully stretched aliphatic ring conformation. Thus all of torsional angles between donor atoms are arranged anti and S...S distance in a ring is 6.764(1)A, which is larger than those values of ortho- and meta-type analogs. The observed high rigidity of the ring conformation may induce the extraordinary behaviors in chelation.