title: Different hydrogen-bonded structures in the isomeric solvates 2-amino-6-anilino-4-methoxy-5-[(E)-4-nitrobenzylideneamino]pyrimidine dimethyl sulfoxide solvate and 2-amino-6-[methyl(phenyl)amino]-5-[(E)-4-nitrobenzylideneamino]pyrimidin-4(3H)-one dimethyl sulfoxide solvate.
abstract: The title solvates, (I) and (II), both C(18)H(16)N(6)O(3).C(2)H(6)OS, are isomeric. The conformations adopted by the 6-substituent are significantly different, with the 6-aminophenyl unit remote from the nitrophenyl ring in methoxypyrimidine (I) but adjacent to it in pyrimidinone (II). Pairs of pyrimidine molecules in (I) are linked by N-H...N hydrogen bonds to form cyclic centrosymmetric dimers from which the dimethyl sulfoxide molecules are pendent, while in (II) a combination of three independent N-H...O hydrogen bonds links the components into a chain containing both R(2)(2)(8) and R(4)(2)(8) rings, in which the dimethyl sulfoxide component acts as a double acceptor of hydrogen bonds. The significance of this study lies in its observation of different conformations for the pyrimidine components in (I) and (II), and different hydrogen-bonded structures, apparently dominated by the different roles adopted by the dimethyl sulfoxide components.
authors.affiliation: Departamento de Química Inorgánica y Orgánica, Universidad de Jaén, 23071 Jaén, Spain.
authors.forename: Ricaurte
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Manuel
authors.initials: M
authors.lastname: Nogueras
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*
chemical_list: D011743:Pyrimidines; D004121:Dimethyl Sulfoxide