In the mol-ecule of the title compound, C(28)H(22)S(2), the two thio-phene rings are twisted with respect to the central benzene ring, making dihedral angles of 71.59 (12) and 50.71 (12)°. The two terminal benzene rings are oriented at dihedral angles of 37.59 (11) and 20.12 (11)° to their bonded thio-phene rings.

We consider rings equipped with a closure operation defined in terms of a collection of commuting idempotents, generalising the idea of a topological closure operation defined on a ring of sets. We establish the basic properties of such rings, consider examples and construction methods, and then concentrate on rings which have a closure operation defined in terms of their lattice of central ide...

The title mol-ecule, C(18)H(12)N(4)S(3), consists of three essentially planar fragments, viz. two methyl-substituted benzonitrile rings and a substituted thia-diazole ring. The dihedral angles between the substituted benzonitrile rings and the central thia-diazole ring are 28.29 (10) and 78.83 (6)°, and the dihedral angle between the two benzonitrile rings is 72.89 (7)°.

Many nearby stars are surrounded by a bright ring or disk of cold dust. Our calculations show that these disks and rings of dust are signposts of recent planet formation. Bright rings appear because dust associated with the formation of a planet absorbs and scatters light from the central star. The calculations explain the rings observed so far and predict that all nascent solar systems have du...

The title compound, C(29)H(27)Cl(2)N(5)O(2), contains a central pyridine ring and two functionalized pyrazoline rings. The pyridine ring and the two attached pyrazoline rings are nearly coplanar, whereas the terminal chloro-phenyl rings are nearly perpendicular to the attached pyrazoline rings [dihedral angles = 86.78 (1) and 77.70 (1)°]. Mol-ecules are linked by weak inter-molecular C-H⋯O hydr...

A new characteristic property of von Neumann regular rings is proposed in terms of annihilators of elements. An ELT fully idempotent ring is a regular ring whose simple left (or right) modules are either injective or projective. Artinian rings are characterized in terms of Noetherian rings. Strongly regular rings and rings whose two-sided ideals are generated by central idempotents are characte...

El papel de las virreinas en dinamicas cortesanas la Nueva Espana ha pasado practicamente desapercibido hasta tiempos recientes. En este articulo se analizaran representaciones simbolicas que tuvieron como protagonista a Juana Diez Aux y Armendariz, marquesa Cadereita, esposa del virrey novohispano Francisco Fernandez Cueva. Para ello seran abordados tres aspectos fundamentales: recreacion figu...

In the title compound, C(14)H(12)ClNO, the central acetamide plane forms dihedral angles of 76.0 (2) and 64.0 (2)° with the phenyl rings and the phenyl rings form a dihedral angle of 71.8 (2)° with each other.