CRYSTAL-STRUCTURES OF THE CIS AND TRANS ISOMERS OF A TETRATHIA[3.3.3.3]CYCLOPHANE

Both the cis and trans isomers of tetrathiatricyclo[26.2.2.1(5.9).2(13 .16).1(20.24)] hexatriaconta 5,7,9,20,22,24-hexene have been prepared and structurally characterized. Each of these centrosymmetric tetrathi a dimers includes two cyclohexane rings in chair conformations with ei ther 1,4-cis or 1,4-tr ans bonding and two meta-substituted benzene ri ngs. The cis isomer packs into the monoclinic space group P2(1)/a with a = 10.485(3)Angstrom b = 10.3956(18)Angstrom c = 14.1343(10)Angstrom beta = 105.200(13)degrees, Z = 2 and refined to an R factor of 0,046. The tracts isomer crystallizes in the monoclinic space,group P2(1)/c with a 10.7217(12)Angstrom b = 5.6797(7)Angstrom c = 25.415(5)Angstrom beta = 96.001(12)degrees Z = 2 and refined to an R factor of 0.043. I n the cis structure each benzene ring faces a cyclohexane ring while i n the trans. structure the cyclohexane rings face one another.