Acidic Ionic Liquid [(CH2)4SO3HMIM][HSO4]: A Green Media for the Simple and Straightforward Synthesis of 2,4,5-Trisubstituted Imidazoles

2,4,5-Trisubstituted imidazoles have been synthesized in excellent yields (85–95%) in the presence of 5 mol% of [(CH₂)₄SO₃HMIM][HSO₄] as a Brønsted acidic ionic liquid.     

Exact solutions in nonlinearly coupled cubic–quintic complex Ginzburg–Landau equations

Exact analytical solutions for pulse propagation in a nonlinear coupled cubic–quintic complex Ginzburg–Landau equations are obtained. Three families of solitary waves which describe the evolutions of progressive bright–bright, front–front, dark–dark and other families of solitary waves are investigated. These exact solutions are analyzed both for competition of loss or gain due to nonlinearity and linearity of the system. The stability of the solitary waves is examined using analytical and numerical methods. The results reveal that the solitary waves obtained here can propagate in a stable way under slight perturbation of white noise and the disturbance of parameters of the system.     

On Critical Points of Proper Holomorphic Maps on The Unit Disk

We prove that a proper holomorphic map on the unit disk in thecomplex plane is uniquely determined up to post-compositionwith a Möbius transformation by its critical points. 1991Mathematics Subject Classification 30C99, 30F45.     

Synthesis of New Multibenzo Oxygen–Sulfur Donor Macrocycles Containing Lactams at Room Temperature

Some new oxygen–sulfur, multibenzo macrocyclic ligands containing amide groups have been prepared using the macrocyclization process with the reaction of 2,2′-thiobis-[4-methyl(2-aminophenoxy)phenyl ether] as a symmetrical diamine with appropriate dicarboxylicacid dichlorides in moderate yields. This macrocyclization led to the formation of di- and tetramide macrocycles. These reactions were routinely carried out at ambient temperature in CH₂Cl₂ as solvent in high dilution without template effect conditions. It is found that sulfur the atom affects the rigidity of the macrocycles and diastereotopicity of nuclei in the ring of these series of macrocyclic compounds.     

Morpholine Catalyzed One‐pot Multicomponent Synthesis of Compounds Containing Chromene Core in Water

A series of dihydropyrano[c]chromene was obtained via condensation of aldehyde, malononitrile and 4‐hydroxycoumarin in water catalyzed by morpholine, as a one‐pot reaction. The significance of our findings relates to reducing the use of organic solvents, potentially toxic and hazardous materials, as well as its simplicity, good yields, mild conditions, and lower costs.     

Dynamic modeling of manipulation of micro/nanoparticles on rough surfaces

In this paper, the dynamic behavior of spherical micro/nanoparticles, while being pushed on rough substrates, is studied by means of an Atomic Force Microscope (AFM). For this purpose, first, the contact adhesion force, and the areas and penetration depths of rough surfaces are derived based on the Johnson-Kendall-Roberts (JKR) theory, the Schwarz method, and the Rumpf/Rabinovich models. Then, the dynamic model of particle manipulation on rough substrates is revised using the specified contact theory for rough surfaces. And finally, the pushing of spherical particles with 50, 100, 200, 500, and 10000 nm radii is simulated. The results show that the critical force and the critical time of manipulation decrease when the particles are pushed on the rough surfaces as compared to the smooth ones. It is also observed that the critical force for a rough substrate containing asperities of low height and large radius approaches a comparable critical force magnitude to the smooth substrate, as is expected. Also, when the asperity radius in the substrate is within the range of 0.5 < r < 5 nm, the critical force of pushing decreases; however, as the asperity radius becomes larger than 5 nm, the critical force begins to increase again. Furthermore, the critical values are generally more sensitive to the changes of the asperity radius than the height. It is also found that the difference between the critical values based on the Rumpf and Rabinovich models is negligible. However, the estimation of particles’ dynamic behavior using the Rumpf model could be wrong for the rough substrates with small radius asperities, which is considerable in the manipulation and assembly practices. Moreover, the dynamic behavior of particles of small radius (r < 500 nm) change during the pushing process on rough surfaces, and the rolling behavior could be possible on the surfaces that have small radius asperities. The probability of this occurrence is increased in the pushing of larger particles on rougher substrates.     

Biomimetic epoxidation of alkenes with sodium periodate catalyzed by tetraphenylporphyrinatomanganese(III) chloride supported on multiwall carbon nanotubes

The biomimetic epoxidation of alkenes catalyzed by tetraphenylporphyrinatomanganese(III) chloride, [Mn(TPP)Cl], immobilized on multiwall carbon nanotubes modified with 4-aminopyridine and 4-aminophenol is reported. These heterogenized catalysts were used as efficient and reusable catalysts for epoxidation of a variety of cyclic and linear alkenes with sodium periodate under mild conditions. The catalysts, [Mn(TPP)Cl@amine-MWCNT], were characterized by physico-chemical and spectroscopic methods. The effect of ultrasonic irradiation on these catalytic systems was also investigated. The catalysts were reused several times without loss of their activity.