A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in w...

The highly exoergic nucleophilic substitution reaction F(-) + CH3I shows reaction dynamics strikingly different from that of substitution reactions of larger halogen anions. Over a wide range of collision energies, a large fraction of indirect scattering via a long-lived hydrogen-bonded complex is found both in crossed-beam imaging experiments and in direct chemical dynamics simulations. Our me...

In this series of papers, we construct operators that extend certain given functions on the boundary of a tetrahedron into the interior of the tetrahedron, with continuity properties in appropriate Sobolev norms. These extensions are novel in that they have certain polynomial preservation properties important in the analysis of high order finite elements. This part of the series is devoted to i...

Abstract: Tetrahedron is the only 3-simplex convex polyhedron having four faces, and its shape has a wide application in science and technology. In this article, using graph theory and combinatorics, a study on a special type of tetrahedron called coxeter Andreev’s tetrahedron has been facilitated and it has been found that there are exactly one, four and thirty coxeter Andreev’s tetrahedrons h...

Our computational and experimental investigation of the reaction of anisole with Cl2 in nonpolar CCl4 solution challenges two fundamental tenets of the traditional SEAr (arenium ion) mechanism of aromatic electrophilic substitution. Instead of this direct substitution process, the alternative addition-elimination (AE) pathway is favored energetically. This AE mechanism rationalizes the preferre...

Supramolecular chemistry represents a way to mimic enzyme reactivity by using specially designed container molecules. We have shown that a chiral self-assembled M4L6 supramolecular tetrahedron can encapsulate a variety of cationic guests with varying degrees of stereoselectivity. Reactive iridium guests can be encapsulated, and the C-H bond activation of aldehydes occurs with the host cavity co...

Two tetrahedra are called orthologic if the lines through vertices of one and perpendicular to corresponding faces of the other are intersecting. This is equivalent to the orthogonality of non-corresponding edges. We prove that the additional assumption of intersecting non-corresponding edges (“orthosecting tetrahedra”) implies that the six intersection points lie on a sphere. To a given tetrah...

Abstract Novel scheelite structures of Li 2 Ca(WO 4 ) , Ca (WO )(SiO ), and LiCa )(PO fluorescent materials were successfully prepared using a high-temperature solid-phase process. The compounds characterized by X-ray diffraction energy dispersive spectroscopy. tests revealed that the substitution [WO ] 2− [SiO 4− or [PO 3− tetrahedron in tungstate had no significant influence on crystal struct...