Synthesis and characterization of new low band‐gap polymers containing electron‐accepting acenaphtho[1,2‐c]thiophene‐S,S‐dioxide groups

Two donor–acceptor conjugated polymers, PTSSO‐TT and PTSSO‐BDT, composed of acenaphtho[1,2‐c]thiophene ‐ S,S‐dioxide (TSSO) as a new electron acceptor and thienothiophene (TT) or benzo[1,2‐b:4,5‐b']dithiophene (BDT) as electron donors, were synthesized with Stille cross‐coupling reactions. The number‐averaged molecular weights (M_n) of PTSSO‐TT and PTSSO‐BDT were found to be 15100 and 26000 Da, with dispersity of 1.8 and 2.4, respectively. The band‐gap energies of PTSSO‐TT and PTSSO‐BDT are 1.56 and 1.59 eV, respectively. The HOMO levels of PTSSO‐TT and PTSSO‐BDT are ?5.4 and ?5.5 eV, respectively. These results indicate that the inclusion of TSSO accepting units into polymers is a very effective method for lowering their HOMO energy levels. The field‐effect mobilities of PTSSO‐TT and PTSSO‐BDT were determined to be 1.5 × 10^?3 and 4.5 × 10^?4 cm² V^?1 s^?1, respectively. A polymer solar cell device prepared with PTSSO‐TT as the active layer was found to exhibit a power conversion efficiency (PCE) of 3.79% with an open circuit voltage of 0.71 V under AM 1.5 G (100 mW cm^?2) conditions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 498–506     

Efficiency of the second-harmonic generation with the zeroth-order bessel-profile beams in uniaxial crystals

We study the efficiency of the second-harmonic generation with the zeroth-order Bessel beam (SHGzoBB) in uniaxial crystals. We show that the conversion efficiency is always less than that of the second-harmonic generation with the Gaussian beam (SHGGB). The fundamental reason relies on the fact that the advantage associated with the ??nondiffractive?? nature of the Bessel beam is not sufficient to compensate the disadvantage of its wave-vector distribution. We show that the zeroth-order Bessel beam is not the optimum beam for the second-harmonic generation in uniaxial crystals.     

Existence Theorems in Vector Optimization with Generalized Order

In the present paper, we establish some results for the existence of optimal solutions in vector optimization in infinite-dimensional spaces, where the optimality notion is understood in the sense of generalized order (may not be convex and/or conical). This notion is induced by the concept of set extremality and covers many of the conventional notions of optimality in vector optimization. Some sufficient optimality conditions for optimal solutions of a class of vector optimization problems, which satisfies the free disposal hypothesis, are also examined.     

Palladium-catalyzed coupling of 2-en-4-yne carbonates with terminal alkynes

The first palladium-catalysed coupling of the carbonates of (E)-configured conjugated enynols with terminal alkynes is described. This method allows the synthesis of vinyl-allenynes with good yields. It has been determined that the method is not suitable for the (Z)-configured substrates.