In the title compound, C(16)H(11)ClN(2)O(2), the pyrazole ring makes dihedral angles of 11.88 (13) and 22.33 (13)° with the 3-chloro-2-hy-droxy-benzene group and phenyl rings, respectively. The phenolic hy-droxy group forms an intra-molecular O-H⋯N hydrogen bond with the imine N atom of the pyrazole unit. The formyl group is virtually coplanar with the pyrazole ring [dihedral angle = 4.5 (19)°]...

Motivated by the search for new examples of “noncommutative manifolds”, we study the noncommutative geometry of the group C*-algebras of various discrete groups. The examples we consider are the infinite dihedral group Z×σZ2 and the semidirect product group Z×σZ. We present a unified treatment of the K-homology and cyclic cohomology of these algebras.

We study properties of a generalization of the Mahler measure to elements in group rings, in terms of the Lück-Fuglede-Kadison determinant. Our main focus is the variation of the Mahler measure when the base group is changed. In particular, we study how to obtain the Mahler measure over an infinite group as limit of Mahler measures over finite groups, for example, in the classical case of the f...

In the title compound, C(15)H(15)NO, the amide fragment has an anti conformation. The central amide group is tilted with respect to the benzoyl ring, forming a dihedral angle of 32.3 (5)°. The benzoyl and aniline rings make a dihedral angle of 59.6 (5)°. Mol-ecules are linked into infinite supra-molecular chains via N-H⋯O hydrogen bonds. The mol-ecule is disordered so that the aromatic rings ar...

Motivated by the search for new examples of “noncommutative manifolds”, we study the noncommutative geometry of the group C*-algebras of various discrete groups. The examples we consider are the infinite dihedral group Z×σZ2 and the semidirect product group Z×σZ. We present a unified treatment of the K-homology and cyclic cohomology of these algebras.

The title compound, C(13)H(19)NO, exhibits a non-planar structure in which the 2,6-diisopropyl-phenyl ring is tilted at a dihedral angle of 77.4 (1)° with respect to the formamide group. This is the largest dihedral angle known among structurally characterized formamides. The mol-ecules are linked via N-H⋯O hydrogen bonds, forming infinite chains which run along the b-axis directions.