In the title mol-ecule, C(13)H(16)O(4), the pyran ring is in a half-chair conformation. There is an intra-molecular hydrogen bond involving the ketone O atom and an H atom of a phenol group which forms an S(6) ring. The ketone O atom is also involved in an inter-molecular hydrogen bond with a different phenolic H atom of a symmetry-related mol-ecule, forming C(6) chains along the c-axis direction.

In the title compound, C(17)H(19)NO(2), the dihedral angle between the two aromatic rings is 26.02 (5)°. One phenol O atom is deprotonated and the N atom of the azomethine unit carries the H atom, forming an intra-molecular hydrogen bond. The packing is stabilized by an O-H⋯O hydrogen bond.

The N-H bond in the title compound, C(13)H(14)NO(3)P, is syn-oriented relative to the P=O bond. The N atom deviates somewhat from planarity, the sum of the bond angles being 353.3°. The P atom has a distorted tetra-hedral coordination; its bond angles are in the range 93.96 (5)-116.83 (6)°. In the crystal, mol-ecules form centrosymmetric dimers through P=O⋯H-N hydrogen bonds.

in the recent years, the coherence index is used in many electroencephalographic studies for investigation of brain connectivity in children with adhd disorder. it is suggested that the coherence is a useful index in discrimination of adhd subjects from normal subjects. however, a few studies are accomplished in subtypes of adhd to identify of differences in functional connectivity between adhd...

Background: Ensuring adequate depth of anesthesia during surgery is essential for anesthesiologists to prevent the occurrence of unwanted alertness during surgery or failure to return to consciousness. Since the purpose of using anesthetics is to affect the central nervous system, brain signal processing such as electroencephalography (EEG) can be used to predict different levels of anesthesia....

let g be a graph. in this paper, we study the eccentric connectivity index, the new version ofthe second zagreb index and the forth geometric–arithmetic index.. the basic properties ofthese novel graph descriptors and some inequalities for them are established.

An anisotropic atom-atom model for the crystalline phases of the molecular S 8 compound We use an anisotropic atom-atom model to describe the crystalline phases of α-, β-and γ-S 8 crystals, the most stable compound of elemental sulfur in solid phase, at ambient pressure and T < ∼ 400K. The calculations are performed via a series of classical molecular dynamics (MD) simulations, with a flexible ...

In the title hydrated salt, 2C(3)H(11)N(2) (+)·C(10)H(6)O(6)S(2) (2-)·2H(2)O, the anion lies on a center of inversion; its sulfonate -SO(3) group features one S-O bond that is longer than the other two. The O atom of this longer bond is the hydrogen-bond acceptor to the amino H atom of one cation and the ammonium H atom of another cation. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the ...

The anion of the title salt, (C(10)H(10)NO)[Zn(C(10)H(8)NO)I(2)]·CH(3)OH, has its metal atom N,O-chelated by the deprotonated 2-methyl-8-hy-droxy-quinoline ligand. The hy-droxy unit of the cation is a hydrogen-bond donor to the alkoxide O atom of the tetra-hedrally coordinated anion, whereas the ammonium cation acts as a hydrogen-bond donor to the methano-lic O atom. In the crystal, adjacent io...