17796-90-6Relevant academic research and scientific papers
Synthesis and structural study of 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene
Aupers, John H.,Skakle, Janet M.S.,Wardell, James L.,Wardell, Solange M.S.V.
, p. 435 - 443 (2007/10/03)
The synthesis, variable temperature NMR spectra, and crystal structures of two crystalline forms, 2a and 2b, of the enamine 1-(N,N-diethylamino)-2,2-bis(2-nitrophenylthio)ethene have been obtained. Both forms crystallize in the monoclinic space group P21/a. The two phases have similar molecular structures but possess different intermolecular C - H ... O hydrogen bonding interactions. Both forms exhibit disorder within the NEt2 fragment at 298 K: sufficient disorder persisted with 2a (orange needles) down to 100 K to make the geometric parameters pertaining to the enamine fragment unreliable. The disorder was effectively eliminated on cooling 2b down (red colored blocks) to 150 K. Cell dimensions for the 2a-phase are at 100 K: a = 11.1030(4) A, b = 15.1325(7) A, c = 12.4504(7) A, β = 114.606(3)°, while for the 2b-phase at 150 K, a = 15.5206(4) A, b = 7.6958(2) A, c = 15.7137(3) A, β = 92.580(7)°. The C - N bond length in the β-form at 150 K of 1.335(3) A indicates considerable double bond character: the rotational barrier of the C - N bond in CDCl3 was calculated to be 52.4 kJ mol-1.
Conformational preferences in 2-nitrophenylthiolates: Interplay between intra-and intermolecular forces; structures of (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, s-(2-nitrophenyl)-benzenecarbothiolate and 1-(2-nitrophenylthio)-2,5-pyrrolidinedione
Low, John N.,Storey, Emily J.,McCarron, Mary,Wardell, James L.,Ferguson, George,Glidewell, Christopher
, p. 58 - 67 (2007/10/03)
In (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, C15H13NO2S (1) (orthorhombic Pbca), the nitro group is almost coplanar with the adjacent aryl ring, but the dihedral angles between the nitro-aryl and styryl fragments is ～121°. The molecules are linked by paired C-H...O hydrogen bonds in a chain of rings. In S-(2-nitrophenyl)benzenecarbothiolate, C13H9NO3S (2) (monoclinic P21/a), the nitro group is rotated by 33.0 (2)° out of the plane of the adjacent aryl ring and the thiobenzoate group is strongly twisted away from the plane of the disubstituted aryl ring. The molecules of (2) are linked into chains by C-H...O hydrogen bonds, and each chain is linked to two neighbouring chains by means of aromatic π...π stacking interactions. In 1-(2-nitrophenylthio)-2,5-pyrrolidinedione, C10H8N2O4S (3) (monoclinic P21/a), the nitro group is again almost coplanar with the adjacent aryl ring, but the pyrrolidinedione unit is almost orthogonal to the O2NC6H4SN plane. There are three types of C-H...O hydrogen bond in the structure, and these link the molecules into a two-dimensional net. The conformations of these molecules have been investigated by SCF calculations and two energy minima have been identified for each: the molecules of (1) and (3) adopt conformations in their crystals which are close to those at the overall energy minima calculated for isolated molecules, while molecules of (2) adopt a conformation in the crystal close to that calculated for the local energy minimum. Comparisons are made with the structures of some related compounds and it is concluded that, while the nature of the two conformational minima is determined by intramolecular forces, the choice between them is determined primarily by intermolecular forces.
