The crystal structures of four cycloalkanespiro-4′-imidazolidine-2′,5′-dithiones, namely cyclopentanespiro-4′-imidazolidine-2′,5′-dithione {systematic name: 1,3-diazaspiro[4.4]nonane-2,4-dithione}, C7H10N2S2, cyclohexanespiro-4′-imidazolidine-2′,5′-dithione {systematic name: 1,3-diazaspiro[4.5]decane-2,4-dithione}, C8H12N2S2, cycloheptanespiro-4′-imidazolidine-2′,5′-dithione {systematic name: 1,3-diazaspiro[4.6]undecane-2,4-dithione}, C9H14N2S2, and cyclooctanespiro-4′-imidazolidine-2′,5′-dithione {systematic name: 1,3-diazaspiro[4.7]dodecane-2,4-dithione}, C10H16N2S2, have been determined. The three-dimensional packing in all of the structures is based on closely similar chains, in which hydantoin moieties are linked through N—H⋯S hydrogen bonding. The size of the cycloalkane moiety influences the degree of its deformation. In the cyclooctane compound, the cyclooctane ring assumes both boat–chair and boat–boat conformations.
Read full abstract