MICROWAVE ASSISTED OXIDATION OF BENZALDEHYDES UNDER SOLVENT-FREE CONDITION USING OXONE®/WET-ALUMINA

The solventless oxidation of benzaldehydes to carboxylic acids using oxone/wet-alumina under microwave irradiations is described.     

A Theoretical Study of OH and OCH3 Free Radical Adsorption on a Nanosized Tube of BC2N

By using density functional theory calculations, we have investigated the adsorption of OH and OCH₃ free radicals on a BC₂N nanotube based on the energetic, electronic and geometric properties. The adsorption of radicals on the top of a B atom is more favorable than that on the other sites and reaction energies have been calculated to be in the range of ?0.57 to ?1.48 eV for OH and ?0.27 to ?1.19 eV for OCH₃. It was found that the adsorption of radicals may facilitate the electron emission from the BC₂N nanotube surface by decreasing the work function due to the charge transfer which occurs between the tube and radicals. Also, HOMO/LUMO gap of the tube is significantly decreased, which may result in the increase of the electrical conductivity of the tube.     

Synthesis,X‐ray Studies,and Catalytic Efficacy of a Novel Iron Complex Containing an N,O‐Type Bidentate Thiazoline Ligand

The reactions of FeCl₃ · 6H₂O and 2‐(2′‐hydroxyphenyl)‐2‐thiazoline as a bidentate O‐N donor thiazoline ligand (thoz) afford a five‐coordinate Fe^III complex [Fe(thoz)₂Cl] with a distorted square pyramidal configuration. Complex [Fe(thoz)₂Cl] was isolated as air‐stable crystalline solids and fully characterized, including by single‐crystal X‐ray structure analysis. Complex [Fe(thoz)₂Cl] shows very efficient reactivity in the oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide (UHP) as the oxidant at room temperature in air.     

Syntheses and characterization of different zinc(II) oxide nano-structures from direct thermal decomposition of 1D coordination polymers

Three zinc(II) nitrite coordination polymers, [Zn(4-bpdb)(NO₂)₂]_n (1), {[Zn(3-bpdb)(NO₂)]·0.5H₂O}_n (2) and [Zn(3-bpdh)(NO₂)₂]_n (3), 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} were prepared and characterized by elemental analyses and IR spectroscopy. Compound 3 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environments of distorted octahedral, ZnN₂O₄. The thermal stabilities of compounds 1–3 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Direct calcination of the compounds 1–3 at 600 °C under air atmospheres yields different morphologies of nano-sized ZnO.     

Switching in Metal–Organic Frameworks

In recent years, metal–organic frameworks (MOFs) have become an area of intense research interest because of their adjustable pores and nearly limitless structural diversity deriving from the design of different organic linkers and metal structural building units (SBUs). Among the recent great challenges for scientists include switchable MOFs and their corresponding applications. Switchable MOFs are a type of smart material that undergo distinct, reversible, chemical changes in their structure upon exposure to external stimuli, yielding interesting technological applicability. Although the process of switching shares similarities with flexibility, very limited studies have been devoted specifically to switching, while a fairly large amount of research and a number of Reviews have covered flexibility in MOFs. This Review focuses on the properties and general design of switchable MOFs. The switching activity has been delineated based on the cause of the switching: light, spin crossover (SCO), redox, temperature, and wettability.     

P-Dodecylbenzenesulfonic acid(DBSA),a Brфnsted acid-surfactant catalyst for Biginelli reaction in water and under solvent free conditions

We report herein the use of p-dodecylbenzenesulfonic acid(DBSA) as a catalyst for a one-pot Biginelli reaction to afford 3,4- dihydropyrimidinone derivatives in good to excellent yields.This reaction proceeds efficiently in water and under solvent free conditions.Comparisons of results indicate that although the yields are high and comparable for both methods,the reaction times are considerably shorter under solvent free conditions.     

On the index of powers of edge ideals

The index of a graded ideal measures the number of linear steps in the graded minimal free resolution of the ideal. In this paper, we study the index of powers and squarefree powers of edge ideals. Our results indicate that the index as a function of the power of an edge ideal I is strictly increasing if I is linearly presented. Examples show that this needs not to be the case for monomial ideals generated in degree greater than two.     

Excess Molar Enthalpies of Monoethanolamine (MEA) + Primary Alkan-1-ols (C3–C6) and their Fitting with Wilson,NRTL and UNIQUAC Models at 298.15 K

Journal of Solution Chemistry - Excess molar enthalpies, $${H}_{\text{m}}^{\text{E}}$$ of binary mixtures of monoethanolamine (MEA) with propan-1-ol, butan-1-ol, pentan-1-ol and hexan-1-ol were...     

二氧化硅键合丙基哌-N-氨基磺酸作为可回收固体酸催化剂制备2-氨基-3-氰基-4-芳基-5,10-二氧代-5,10-二氢-4H-苯并[g]苯并吡喃和羟基取代的萘-1,4-二酮衍生物(英文)

An efficient method for the synthesis of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H- ben-zo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives, using silica-bonded propylpiperazine-N-sulfamic acid as a solid acid, green, heterogeneous catalyst, under ambient and solvent-free conditions, is described. A simple procedure, high yields, short reaction time, safety, and reusability of the catalyst are advantages of these protocols.