Conformational preferences and supramolecular aggregation in 2-nitrophenylthiolates: disulfides and thiosulfonates.

In each of the asymmetrically substituted disulfides 2-nitro-4'-methyldiphenyl disulfide, C(13)H(11)NO(2)S(2) (1), 2-nitro-4'-chlorodiphenyl disulfide, C(12)H(8)ClNO(2)S(2) (2), 2, 4-dinitro-4'-methyldiphenyl disulfide, C(13)H(10)N(2)O(4)S(2) (3), and 2,4-dinitrophenyl-2'-methoxycarbonylmethyl disulfide, C(9)H(8)N(2)O(6)S(2) (4), and in both of the symmetrically substituted disulfides bis(2-nitrophenyl) disulfide, C(12)H(8)N(2)O(4)S(2) (5), and bis(2-nitro-4-trifluoromethylphenyl) disulfide, C(14)H(6)F(6)N(2)O(4)S(2) (6), the 2-nitro groups are essentially coplanar with the adjacent aryl ring and the S atom remote from the nitrated aryl ring is also essentially coplanar and transoid to the nitro group. In S-(2-nitrophenyl) 2-nitrobenzene thiosulfonate, C(12)H(8)N(2)O(6)S(2) (7), which contains three independent molecules in the asymmetric unit, all six of the independent nitro groups are twisted out of the plane of the adjacent aryl rings. The crystal structures of (1)-(3) contain isolated molecules, that of (4) contains centrosymmetric dimers held together by C-H.O hydrogen bonds, while in the structures of (5)-(7), respectively, the C-H.O hydrogen bonds generate one-, two- and three-dimensional arrays. The interplay between molecular conformation and supramolecular aggregation is discussed.