The asymmetric unit of the title compound, C(11)H(16)N(2)O(2), contains two independent conformational isomers which show intra-molecular aromatic-imine O-H⋯N hydrogen bonds. In the crystal, neighboring mol-ecules are linked through inter-molecular aliphatic-aliphatic O-H⋯N, aliphatic-aromatic N-H⋯O and C-H⋯O inter-actions into hydrogen-bonded layers parallel to the ab plane.

The title compound, C21H23BrO3 [systematic name: (3E,3aS,6Z,9R,9aS,9bS)-3-(2-bromo-benzyl-idene)-9-hy-droxy-6,9-dimethyl-3,3a,4,5,7,8,9,9a-octa-hydro-azuleno[4,5-b]furan-2(9bH)-one] was prepared by the reaction of 1-bromo-2-iodo-benzene with micheliolide [systematic name: (3aS,R,9aS,9bS,Z)-9-hy-droxy-6,9-dimethyl-3-methyl-ene-3,3a,4,5,7,8,9,9a-octa-hydro-azuleno[4,5-b]furan-2(9bH)-one] under He...

The title compound, C(15)H(17)FO, was prepared directly from the aldol condensation of cyclo-octa-none with 4-fluoro-benz-aldehyde, catalysed by Pd(Ni,Ce) in the presence of trimethyl-silyl chloride. The eight-membered ring adopts a boat-chair conformation.

The asymmetric unit of the title compound, C14H11FN2O, contains two independent mol-ecules, both of which adopt the E conformation with respect to the azomethine C=N bond. The mol-ecules are non-planar, with dihedral angles of 26.92 (12) and 11.36 (11)° between the benzene and phenyl rings. In the crystal, mol-ecules are linked through N-H⋯O=C and N-H⋯N hydrogen bonds into chains along [101]. C...

The general nonlinear scalar model is studied at asymptotically low temperature near two dimensions. The low temperature expansion is renormalized and effective algorithms are derived for calculation to all orders in the renormalized expansion. The renormalization group coefftcients are calculated in the two loop approximation and topological properties of the renormalization group equations ar...

In the title compound, C(10)H(11)N(3), the amidine unit, including the two methyl substituents, is virtually planar [maximum deviation = 0.016 (5) Å]. The plane of the benzene ring forms a dihedral angle of 46.5 (3)° with the amidine group.

In the title compound, C(44)H(48)N(6), the essentially planar mol-ecule [maximum deviation from the mean plane of the π system of 0.271 (3) Å] is located on a crystallographic centre of inversion. The almost planar (angle sums at N atoms = 357.6 and 357.1°) dimethyl-amino groups and short C-N bonds of the aniline groups [both 1.379 (4) Å] indicate strong electronic coupling between these groups...

In the crystal of the title 1:1 adduct, C(8)H(7)ClO(2)·C(12)H(10)N(4), the components are linked by an O-H⋯N hydrogen bond between the carb-oxy-lic acid and one of the pyridine N atoms. In the acid, the carb-oxy-lic acid group is approximately normal to [dihedral angle = 72.9 (2)°] but twisted with respect to the plane through the benzene ring [C-C-C-O torsion angle = 25.4 (5)°]. The base is ro...