Synthesis of some novel annelated 1,2,3‐selena/thiadiazoles and 2h‐diazaphospholes

A number of annelated heterocyclic indene derivatives having 1,2,3‐selena/thiadiazole and 2H‐1,2,3‐diazaphosphole rings have been synthesized by exploiting the α‐ketomethylene functionality in some novel 1‐methyl‐piperidin‐4‐ones and 1‐oxo‐tetrahydrothiopyran‐4‐ones and were characterized by their physical and spectral data.     

Algorithms for the computation of Hankel functions of complex order

Hankel functions of complex order and real argument arise in the study of wave propagation and many other applications. Hankel functions are computed using, for example, Chebyshev expansions, recursion relations and numerical integration of the integral representation. In practice, approximation of these functions is required when the order and the argumentz are large.When andz are large, the Chebyshev series expansion of the Hankel function is of limited use. The situation is remedied by the use of appropriate asymptotic expansions. These expansions are normally expressed in terms of coefficients which are defined recursively involving derivatives and integrals of polynomials. The applicability of these expansions in both numerical and symbolic software is discussed with illustrative examples.     

Oxidations by iron(VI). Kinetic study of uncatalysed and osmium(VIII) catalysed oxidation of dimethyl sulphoxide in alkaline medium

Summary Uncatalysed and Os^VIII-catalysed oxidation of dimethyl sulphoxide (DMSO) by potassium ferrate [Fe^VI] has been studied in alkaline medium in the 9.8–11.9 pH range, in the presence of IO ₄ ^– as a stabilizing agent. The order in [Fe^VI] and [DMSO] was found to be unity for the uncatalysed reaction and zero and fractional respectively for the catalysed reaction. The [Os^VIII] order was unity in the catalysed reaction. The rate of oxidation decreased with increase in pH and the order in [H⁺] was fractional for the uncatalysed oxidation. However in the catalysed oxidation, the rate at first decreased and then increased with increase in pH. The effect of changing [IO ₄ ^– ] and [buffer] on the oxidation rate was negligible in both cases. Suitable mechanisms consistent with the observed kinetics have been proposed.     

Stereoselective syntheses of (+)-goniodiol, (-)-8-epigoniodiol,and (+)-9-deoxygoniopypyrone via alkoxyallylboration and ring-closing metathesis

A convenient synthesis of (+)-goniodiol, (-)-8-epigoniodiol, and (+)-9-deoxygoniopypyrone has been developed via asymmetric alkoxyallylboration and ring-closing metathesis pathways.     

Design of bicontinuous donor/acceptor morphologies for use as organic solar cell active layers

In recent works, we demonstrated the achievement of bicontinuous donor/acceptor morphologies by the addition of conjugated block copolymers to a blend of conjugated homopolymer donors and fullerene acceptors. However, the domain sizes resulting in experiments were much larger than those of interest for high‐performance organic solar cells. Moreover, a significant concentration of fullerene acceptors was present in the donor domains. Here, we utilize simulations to study the bicontinuous donor/acceptor morphologies that result for different parametric conditions. Using such results, we provide guidelines for how to blend polymer materials to give rise to bicontinuous phases with the smaller and more compositionally pure domains that are desirable for organic photovoltaic applications. Our results can be generalized to treat a large range of donor and acceptor monomers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 884–895     

Noncontinuum effects on the mobility of nanoparticles in unentangled polymer solutions

The results for the diffusivity of nanoparticles in unentangled semidilute polymer solutions obtained using coarse‐grained simulations are presented. The results indicate that for particle sizes smaller than the polymer radius of gyration, the nanoparticle diffusivities deviate from Stokes–Einstein predictions and depend explicitly on the polymer radius of gyration and the polymer solution correlation lengths. Scaling ideas proposed are invoked for rationalizing such noncontinuum effects and demonstrate that the simulation results could be collapsed onto a single universal function of the depletion thickness, the polymer radius of gyration, and the particle radius. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2145–2150.     

An efficient one-step chemoselective reduction of alkyl ketones over aryl ketones in β-diketones using LiHMDS and lithium aluminium hydride

β-Hydroxy ketones were synthesized in one-pot from β-diketones by reducing alkyl ketones chemoselectively by keeping aryl ketone intact. Initially, β-diketones were enolized using LiHMDS and later alkyl ketone was chemoselectively reduced efficiently by lithium aluminium hydride. This method produces β- hydroxyl ketones from the corresponding β-diketones in high yield.