In the title compound, C(21)H(19)N(3)O(4), two intramolecular N-H⋯O hydrogen bonds generate two six-membered rings. The dihedral angles between the central heterocyclic ring and the two pendant rings are 61.5 (2) and 63.5 (1)°.

In the title compound, C(15)H(14)O(3)S, the dihedral angle between the two benzene rings is 59.3 (8)°. The crystal structure is stabilized by weak inter-molecular C-H⋯π inter-actions between the benzene rings and the central ethyl-ene bridge, and a weak non-classical C-H⋯O hydrogen bond occurs in the structure.

In the crystal structure of the title compound, C(24)H(24)N(2)O(4), the dihedral angles between the central and the two outer benzene rings are 48.12 (8) and 21.44 (8)°. Intra-molecular O-H⋯N hydrogen bonding generates S(6) rings.

The title compound, C(19)H(20)O(5), is approximately planar; the dihedral angle between the benzene rings is 3.82 (8)°, and the central propenone C(=O)-C=C plane makes dihedral angles of 1.95 (10) and 3.17 (11)° with the two benzene rings. In the crystal structure, intra- and inter-molecular C-H⋯O hydrogen bonds are observed.

Ring stacking in some closo-borane dianions and the hypothetical capped borane nanotubes, predicted to be stable earlier, is analyzed in a perturbation theoretic way. A "staggered" building up of rings to form nanotubes is explored for four- and five-membered B(n)H(n) rings. Arguments are given for the stacking of B(5)H(5) rings being energetically more favorable than the stacking of B(4)H(4) r...

Problem statement: Algebraic K-theory of projective modules over commutative rings were introduced by Bass and central simple superalgebras, supercommutative super-rings were introduced by many researchers such as Knus, Racine and Zelmanov. In this research, we classified the projective supermodules over (torsion free) supercommutative super-rings and through out this study we forced our selves...

for any reduced commutative $f$-ring with identity and bounded inversion, we show that a condition which is obviously necessary for the socle of the ring to coincide with the socle of its bounded part, is actually also sufficient. the condition is that every minimal ideal of the ring consist entirely of bounded elements. it is not too stringent, and is satisfied, for instance, by rings of conti...

recently testing of quantum-dot cellular automata (qca) circuits has attracted a lot of attention. in this paper, qca is investigated for testable implementations of reversible logic. to amplify testability in reversible qca circuits, a test method regarding to built in self test technique is developed for detecting all simulated defects. a new reversible qca mux 2×1 design is proposed for the ...

PURPOSE To evaluate the safety and efficacy of Ferrara intrastromal corneal rings in the treatment of eyes with keratoconus without central corneal scarring. SETTING Vlemma Eye Institute, Athens, Greece. METHODS Twenty-six patients with bilateral keratoconus, clear central corneas, and contact lens intolerance participated in the study. Videokeratographic corneal topography and ultrasonic p...

The tripodal character of the title compound, C(33)H(30)N(10)S(3), arises from the three thio-ether arms surrounding a central amine N atom. The three arms have approximately the same conformation but distinct geometries in a trans-trans-cis conformation, resulting in a short pyridine-sulfanyl N⋯S distance of 4.320 (7) Å. The distances of the central N atom to the N atoms of three pyridine ring...