In the title compound, C(18)H(17)N(3), the dihedral angles between the central pyrimidine ring and its directly-bonded and N-bonded pendant phenyl rings are 25.48 (6) and 80.33 (6)°, respectively. The dihedral angle between the phenyl rings is 79.66 (6)°. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R(2) (2)(8) loops. The crystal structure also features weak...

BACKGROUND Trimethoprim [2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine] is an antifolate drug. It selectively inhibits the bacterial dihydrofolate reductase (DHFR) enzyme. RESULTS In the crystal structures of trimethoprim (TMP)-hydrogen phthalate (1) and trimethoprim-hydrogen adipate (2), one of the N atoms of the pyrimidine ring is protonated and it interacts with the deprotonated carb...

UV-Vis measurements showed that the interaction of pseudohalide anions, A(-) (A(-) = N3(-), NCO(-), NCS(-)), with electrophilic bromocarbons, R-Br (R-Br = CBr4, CBr3NO2, CBr3CONH2, CBr3H, CBr3F, CBr3CN or C3Br2F6), in solution results in formation of [R-Br, A(-)] complexes. These associates are characterized by intense absorption bands in the 200-350 nm range showing distinct Mulliken correlati...

The title crystal structure, C(11)H(18)N(4)O(3), is the first diazo-acetamide in which the diazo-acetyl group is attached to an N atom. The piperazine ring is in a chair form and hence the mol-ecule has an extended conformation. Both ring N atoms are bonded in an essentially planar configuration with the sum of the C-N-C angles being 359.8 (2) and 357.7 (2)°. In the crystal structure, the O ato...

In the title compound, {[Mn(C(14)H(16)N(5)O(3))(2)]·2H(2)O}(n), the Mn(II) atom (site symmetry ) exhibits a distorted trans-MnN(2)O(4) octa-hedral geometry defined by two monodentate N-bonded and two bidentate O,O'-bonded 8-ethyl-5-oxo-2-(piperazin-1-yl)-5,8-dihydro-pyrido[2,3-d]pyrimidine-6-carboxyl-ate anions. An N-H⋯O hydrogen bond is present in the crystal structure. The extended two-dimens...

In the title compound, [Ni(CHO(2))(2)(C(4)H(4)N(2))(H(2)O)], the nickel(II) cations are coordinated by three O-bonded-formato anions, two N-bonded-pyrazine ligands and one water mol-ecule in an octa-hedral coordination mode. The nickel(II) cations are connected by μ-1,3-bridging formato anions and N,N'-bridging pyrazine ligands into a three dimensional coordination network. The asymmetric unit ...

In the title compound, {[Cu(C(16)H(17)FN(3)O(3))(2)]·4H(2)O}(n), the Cu(II) atom is bonded to two O,O'-bidentate 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-quinoline-3-carboxyl-ate (norf) monoanions and a symmetry-generated N-bonded norf anion, resulting in a distorted square-pyramidal coordination environ-ment with the N atom occupying the apical site. The bridging norf anion result...

In the title compound, C(4)H(8)N(5) (+)·Cl(-), a two-dimensional layer packing network is observed in which every chloride anion links three adjacent 2,4-diamino-6-methyl-1,3,5-triazin-1-ium cations by N-H⋯Cl hydrogen-bonding inter-actions, forming 12-membered and eight-membered hydrogen-bonded rings with graph-set motifs R(4) (4)(12) and R(3) (3)(8), respectively. In addition, N-H⋯N hydrogen b...

Energetics and geometrical structures of neutral, (H2O)n, and ionized, (H2O)n, water clusters, with n ) 2-5, are investigated using local-spin-density functional electronic structure calculations with exchange-correlation gradient corrections. While the ground-state structures of the neutral clusters are hydrogen-bonded cyclic ones, those of the molecular ions are noncyclic. The lowest energy i...

Diketopyrrolopyrroles (DPPs) have recently gained attention as building-blocks for organic semiconducting polymers and small molecules, however the semiconducting properties of their hydrogen-bonded (H-bonded) pigment forms have not been explored. Herein we report on the performance of three archetypical H-bonded DPP pigments, which show ambipolar carrier mobilities in the range 0.01-0.06 cm2/V...