title: Hydrogen-bonded ribbons in ethyl (E)-3-[2-amino-4,6-bis(dimethylamino)pyrimidin-5-yl]-2-cyanoacrylate and 2-[(2-amino-4,6-di-1-piperidylpyrimidin-5-yl)methylene]malononitrile.
abstract: The pyrimidine rings in ethyl (E)-3-[2-amino-4,6-bis(dimethylamino)pyrimidin-5-yl]-2-cyanoacrylate, C(14)H(20)N(6)O(2), (I), and 2-[(2-amino-4,6-di-1-piperidylpyrimidin-5-yl)methylene]malononitrile, C(18)H(23)N(7), (II), which crystallizes with Z' = 2 in the P1 space group, are both nonplanar with boat conformations. The molecules of (I) are linked by a combination of N-H...N and N-H...O hydrogen bonds into chains of edge-fused R(2)(2)(8) and R(4)(4)(20) rings, while the two independent molecules in (II) are linked by four N-H...N hydrogen bonds into chains of edge-fused R(2)(2)(8) and R(2)(2)(20) rings. This study illustrates both the readiness with which highly-substituted pyrimidine rings can be distorted from planarity and the significant differences between the supramolecular aggregation in two rather similar compounds.
authors.affiliation: Departamento de Química, Universidad de Valle, AA 25360 Cali, Colombia.
authors.forename: Jorge
authors.initials: J
authors.lastname: Trilleras
authors.forename: John N
authors.initials: JN
authors.lastname: Low
authors.forename: Justo
authors.initials: J
authors.lastname: Cobo
authors.forename: Antonio
authors.initials: A
authors.lastname: Marchal
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell
mesh_terms: D018360:Crystallography, X-Ray; D003487:Cyanoacrylates / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*
chemical_list: C527948:2-((2-amino-4,6-di-1-piperidylpyrimidin-5-yl)methylene)malononitrile; D003487:Cyanoacrylates; D009570:Nitriles; D011743:Pyrimidines; C527947:ethyl 3-(2-amino-4,6-bis(dimethylamino)pyrimidin-5-yl)-2-cyanoacrylate