PCl5 as a mild and efficient catalyst for the synthesis of bis(indolyl)methanes and di-bis(indolyl)methanes

Phosphorus pentachloride (PCl5) can efficiently catalyze the condensation of indoles with aldehydes as well as ketones at room temperature to afford bis(indolyl)methanes and di-bis(indolyl)methanes in high yields and short reaction times. KEY WORDS: PCl5, bis(Indolyl)methane, di-bis(Indolyl)methane, Indole, Aldehyde, Ketone  Bull. Chem. Soc. Ethiop. 2008, 22(3), 453-458

(3R*,4R*)-1-(4-Chloro­phen­yl)-4-[2-hy­droxy-3-(morpholinomethyl)­phen­yl]-3-phen­oxy­azetidin-2-one

The β-lactam ring of the title compound, C26H25ClN2O4, is nearly planar (r.m.s. deviation = 0.025 Å) and the morpholine ring adopts a chair conformation. The mean plane of the β-lactam ring makes dihedral angles of 21.6 (4), 84.4 (4) and 33.7 (4)° with the two benzene rings and the phenyl ring, respectively. The conformation of the title compound is stabilized by intra­molecular C—H⋯O and O—H⋯N inter­actions. The crystal structure features C—H⋯π and aromatic π–π stacking inter­actions [centroid–centroid distances = 3.684 (4) and 3.883 (4) Å]

Bis(2-hydroxy­benzaldehyde oxime) O,O′-butane-1,4-diyldicarbonyl ether

The mol­ecule of the title compound, C20H20N2O6, lies across a crystallographic inversion centre, the asymmetric unit comprising one half-mol­ecule. An intra­molecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. Pairs of inter­molecular C—H⋯O hydrogen bonds link neighbouring mol­ecules into a layer with R 2 2(38) ring motif. The crystal structure is further stabilized by the inter­molecular C—H⋯π inter­actions

The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species

2-[(E)-(4-Methyl­phen­yl)imino­meth­yl]-6-(morpholin-4-ylmeth­yl)phenol

In the title compound, C19H22N2O2, the morpholine ring adopts an almost perfect normal chair conformation with puckering parameters Q T, θ and ϕ of 0.5642 (18) Å, 177.32 (17) and ϕ = 10 (4)°, respectively. The two benzene rings make a dihedral angle of 42.67 (8)° with each other. An intra­molecular O—H⋯N hydrogen bond helps to stabilize the mol­ecular conformation. Aromatic C—H⋯π inter­actions and π–π stacking inter­actions [centroid–centroid distance = 3.6155 (15) Å] between the benzene rings contribute to the stabilization of the crystal structure

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

This review article discusses the progress related to the synthesis and catalytic applications of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials for industrial and laboratory products. These catalysts are widely used in acid-catalyzed processes. Most of these acid catalysts are eco-friendly, reusable, and stable. Moreover, the discovery of unique catalysts is vital for developing new, efficient, and reusable catalysts for industrial and laboratory applications. The aim of this review article is to review the recent studies (2014–2018) in the field of the utility of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials for developing acidic catalysts

Design of a Selective and Sensitive PVC-Membrane Potentiometric Sensor for Strontium Ion Based on 1,10-Diaza-5,6-benzo-4,7-dioxacyclohexadecane-2,9-dioneas a Neutral Ionophore

A novel PVC membrane sensor for the Sr2+ ion based on 1,10-diaza-5,6-benzo-4,7- dioxacyclohexadecane-2,9-dione has been prepared. The sensor possesses a Nernstian slope of 30.0 ± 0.6 mV decade-1 over a wide linear concentration range of 1.6 × 10-6-3.0 ×10-3 M with a detection limit of 6.3 ×10-7 M. It has a fast response time of less than 15 s and can be used for at least two months without any considerable divergence in potential. The potentiometric response is independent of the pH of test solution in the pH range 4.3-9.4. The proposed electrode shows good selectivities over a variety of alkali, alkaline earth, and transition metal ions

Solvent-free and room temperature synthesis of 3-arylquinolines from different anilines and styrene oxide in the presence of Al2O3/MeSO3H

A highly efficient, simple and environmentally friendly synthesis of 3-arylquinolines has been developed in the presence of Al2O3/MeSO3H via one-pot reaction of anilines and styrene oxide. This methodology provides very rapid access to 3-arylquinolines in good to excellent yields under solvent-free conditions at room temperature in air

A low-overpotential nature-inspired molecular chromium water oxidation catalyst

The function of tyrosine Yz in photosystem II (PSII) has been considered as a model for establishing a new homogeneous water oxidation catalyst (WOC). In this work, we designed and synthesized a diphenoxybased salen-type Schiff base ligand (L) in order to overcome the problems that so far have prevented the use of chromium complexes as water oxidation catalysts (WOCs). Cyclic voltammetry measurements performed in the alkaline solution of [Cr(L-2H)Cl] (1) displayed a large irreversible oxidation waves, corresponding to the catalytic water oxidation. The main species in the catalytically active solutions is found to be [Cr(L-2H)ClOH]-∙ The proposed catalytic system generates a current density (J) of 1.0mA cm2 at the relatively low overpotential (ƞ) of 0.426 V with a high turnover frequency (TOF) of 49.7 s-1. A comprehensive mechanistic study was carried out based on the results of experiments, calculations and according to previous works. The computational calculations supported the importance of the uncoordinated eOH groups present in the ligand moiety of the complex for the oxidation of Cr3+ to Cr4+