‘Click Synthesis’ of Some Novel Benzimidazol Oxime Ethers Containing Heterocycle Residues as Potential ß‐Adrenergic Blocking Agents

The ‘click synthesis’ of some novel O‐substituted oximes, 5a – 5j , which contain heterocycle residues, as new analogs of ß‐adrenoceptor antagonists is described (Scheme 1). The synthesis of these compounds was achieved in four steps. The formation of (E)‐2‐(1H‐benzo[d]imidazol‐1‐yl)‐1‐phenylethanone oxime, followed by their reaction with 2‐(chloromethyl)oxirane, afforded mixture of oil compounds 3 and 4 , which by a subsequent tetra‐n‐butylammonium bromide (TBAB)‐catalyzed reaction with N H heterocycle compounds (Scheme 1), led to the target compounds 5a – 5j in good yields.     

Voltammetric determination of droxidopa in the presence of carbidopa using a nanostructured base electrochemical sensor

A novel carbon paste electrode modified with ZnO nanorods and 2-(4-oxo-3-phenyl-3,4-dihydroquinazolinyl)-N′-phenyl-hydrazinecarbothioamide (2PHCZNCPE) was fabricated and employed to study the electrocatalytic oxidation of droxidopa, using cyclic voltammetry, chronoamperometry and square wave voltammetry as diagnostic techniques. It has been found that the oxidation of droxidopa at the surface of modified electrode occurs at a potential of about 435 mV less positive than that of an unmodified carbon paste electrode. Square wave voltammetry exhibits a linear dynamic range from 7.0 × 10^–8 to 3.0×10^?4 M and a detection limit of 45.0 nM for droxidopa. Finally this modified electrode was used for simultaneous determination of droxidopa and carbidopa.     

Synthesis, characterization and fluorimetric studies of novel photoactive poly(amide-imide) from anthracene 9-carboxaldehyde and 4,4′-diaminodiphenyl ether by microwave irradiation

Trimellitic anhydride acid chloride (2) was obtained by the reaction of trimellitic anhydride (1) and excess amount of thionyl chloride. The acid chloride was reacted with 4,4′-diaminodiphenyl ether (3), and produced the monomer 4. Anthracene-9-carboxaldehyde (5) was reacted with sulfuryl chloride to produce anthracene-9-carboxylic acid chloride (6) in a quantitative yield. Through the reaction of 6 and 2,4,6-triamino-1,3,5-triazine (7), the monomer 8 was produced in high yield. Two monomers were characterized by ¹H NMR and FT-IR spectroscopy, and then were used in the polymerization reaction. A new facile and rapid polycondensation reaction of the two monomers was performed by using a domestic microwave oven. The polymerization reaction proceeded rapidly, compared with the conventional solution polycondensation and was completed within 10 min, producing a photoactive poly(amide-imide) in a quantitative yield. The resulting polymer was characterized by IR, ¹H NMR and TGA techniques. Thermogravimetric analysis indicated that polymer 9 was thermally stable in nitrogen atmosphere. In addition the initial decomposition temperature, 5% and 10% weight loss (T5, T10) were 284, 356 and 408 °C. The residual weight percent at 700 °C was 51.5%, which shows it is moderately thermally stable. Fluorescence properties of polymer 9 were investigated in several solvents. The ideal concentration of each case was determined by fluorescence self quenching phenomena. Also the self quenching mechanism was studied according to the specific behavior of the polymer in different solvents.     

Fe3O4@C@OSO3H as an efficient,recyclable magnetic nanocatalyst in Pechmann condensation: green synthesis,characterization, and theoretical study

Molecular Diversity - Novel sulfonated carbon-coated magnetic nanoparticles (SCCMNPs; Fe3O4@C@OSO3H) were designed, synthesized, characterized, and applied as an efficient nanocatalyst for green...     

Fully Integrated Microscale Quasi‐2D Crystalline Molecular Field‐Effect Transistors

Monolithic integration of microscale organic field‐effect transistors (micro‐OFETs) is the only and inevitable path toward low‐cost large‐area electronics and displays. However, to date, such an ultimate technology has not yet evolved due to challenges in positioning and patterning highly crystalline microscale molecular layers as well as in developing micrometer scale integration schemes. In this work, by mastering the local growth of molecular semiconductors on pre‐defined terraces, single‐crystal quasi‐2D molecular layers tens of square micrometers in size are created in dense periodic arrays on a Si substrate. Nondestructive photolithographic processes are developed to pattern micro‐OFETs with mobilities up to 34.6 cm² V^?1 s^?1. This work demonstrates the feasibility to integrate arrays of short‐channel micro‐OFETs into electronic circuitry by highly parallel and size scalable fabrication technologies.     

Highly ordered mesoporous La(III)-substituted 5-oxopyrrolidine-2-carboxylic acid (Glp) immobilized on SBA-15 as a very efficient nanocatalyst for green aerobic oxidative coupling of thiols to disulfides

Selective aerobic oxidative coupling of thiols that are catalyzed by La(III)-substituted 5-oxopyrrolidine-2-carboxylic acid (Glp) immobilized on SBA-15 (SBA-15@Glp–La; SBA = Santa Barbara amorphous) was studied. Using SBA-15@Glp–La, the complete conversion was achieved at room temperature in the presence of air without producing any over-oxidized yields. SBA-15@Glp–La was prepared by post-grafting technique. 5-Oxopyrrolidine-2-carboxylic acid (Glp) condensation followed by La(III) impregnation caused this La(III)-grafted 5-oxopyrrolidine-2-carboxylic acid (Glp) to immobilize on SBA-15. This SBA-15@Glp–La catalyst shows excellent catalytic activity in the selective aerobic oxidative coupling of thiols. Effects of amount of the catalyst, polarity of the solvent, effects of substrate, and catalyst reusability were investigated. It has been observed that seven repetitive reaction cycles did not cause any appreciable loss in the catalytic activity of this catalyst. The catalyst characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, transmission electron microscopy, inductively coupled plasma, elemental mapping, and N₂ adsorption–desorption is reported. The procedure developed is heterogeneous and environmentally benign.     

Synthesis and application of novel 1,2,3‐triazolylferrocene‐containing ionic liquid supported on Fe3O4 nanocatalyst in the synthesis of new pyran‐substituted Betti bases

A novel magnetic ferrocene‐labelled ionic liquid based on triazolium, [Fe₃O₄@SiO₂@Triazol‐Fc][HCO₃], has been synthesized and has been successfully introduced as a recyclable heterogeneous nanocatalyst. The catalytic activity of the novel magnetic nanoparticles was evaluated in the one‐pot three‐component synthesis of a wide variety of Betti bases. A simple, facile and highly efficient green method has been developed for the synthesis of kojic acid‐containing Betti base derivatives at room temperature. Additionally, this new protocol has notable advantages such as short reaction times, green reaction conditions, high yields and simple workup and purification steps. Also, the novel nanocatalyst could be easily recovered using an external magnetic field and reused for six consecutive reaction cycles without significant loss of activity. The newly synthesized nanocatalyst was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller measurements.     

Real options analysis of investment in carbon capture and sequestration technology

Among a comprehensive scope of mitigation measures for climate change, CO₂ capture and sequestration (CCS) plays a potentially significant role in industrialised countries. In this paper, we develop an analytical real options model that values the choice between two emissions-reduction technologies available to a coal-fired power plant. Specifically, the plant owner may decide to invest in either full CCS (FCCS) or partial CCS (PCCS) retrofits given uncertain electricity, CO₂, and coal prices. We first assess the opportunity to upgrade to each technology independently by determining the option value of installing a CCS unit as a function of CO₂ and fuel prices. Next, we value the option of investing in either FCCS or PCCS technology. If the volatilities of the prices are low enough, then the investment region is dichotomous, which implies that for a given fuel price, retrofitting to the FCCS (PCCS) technology is optimal if the CO₂ price increases (decreases) sufficiently. The numerical examples provided in this paper using current market data suggest that neither retrofit is optimal immediately. Finally, we observe that the optimal stopping boundaries are highly sensitive to CO₂ price volatility.