Crystal structure of cyclotetra(1,4-dithiobenzene), C24H16S8

Source of material: 350 mg of iron(II) sulfate heptahydrate was dissolved in 20 ml of dimethylformamide.To remove small amounts of insoluble solids, this mixture was Altered.A 5 ml dimethylformamide solution containing 50 mg of 1,4-benzenedithiol was added to the fíltrate.The resulting black solution was placed in a 50 ml Erlenmeyer flask and allowed to stand in air.The color gradually turned orange-red after two hours.Pale yellow rectangular parallelepipedal crystals of the title compound formed after four days.The crystals were collected and washed with ethanol (3 χ 10 ml), then air dried to give 30 mg of product (60% yield based on 1,4-benzenedithiol).The crystals are air stable and are poorly soluble in water, methanol, ethanol, acetone, acetonitrile, toluene and dimethylformamide.However, they are soluble in chloroform and tetrahydrofuran.Elemental microanalysis calculated for C24H16S8: C, 51.39; H, 2.88; S, 45.65.