A series of evolving frontier energy levels and gaps sulfone-containing thienylenevinylene-based conjugated copolymers have been synthesized via the Horner-Emmons reactions between 2,5-bisdiethoxyphosphorylmethyl-3,4-dihexyl-1,1-dioxothiophene and a series of different donor type dialdehyde comonomers. The resulting polymers (SF-PTVs) contain alternating donor (benzene or thiophene ring with/without alkoxy substituents) and acceptor (1,1-dioxothiophene) units. A range of HOMO/LUMO levels and energy gaps (between 1.0 and 2.0 eV) were achieved in these new polymers. The use of oxidized thiophene moiety brings about 0.3 eV in reduction of energy gap. Computational study on the model oligomers of P(C6OTV-SFTV) and related structures reveals that the reduction is mainly due to the removal of aromaticity of the thiophene. The donor-acceptor interaction is also responsible for about one-third or less of the energy gap reduction. Theses polymers have very good thermal stability (dynamically, 258 °C or higher), and their decomposition starts with loss of mass as in contrast to regular PTVs which decompose initially by cross-linking.

The iron-organic framework VNU-20 was utilized as an active heterogeneous catalyst for the crossdehydrogenative coupling of coumarins with Csp 3 -H bonds in alkylbenzenes, cyclohexanes, ethers, and formamides. The combination of DTBP as the oxidant and DABCO as the additive led to high yields of coumarin derivatives. The VNU-20 was more active towards this reaction than numerous other homogeneous and heterogeneous catalysts. Heterogeneous catalysis was confirmed for the crossdehydrogenative coupling transformation utilizing the VNU-20 catalyst, and the contribution of active iron species in the liquid phase was insignificant. The iron-based framework was reutilized many times for the functionalization of coumarins without a remarkable decline in catalytic efficiency. To the best of our knowledge, these reactions of coumarins have not previously been conducted using heterogeneous catalysts.

A novel conjugated block copolymer system containing a donor‐type conjugated block (c‐D) covalently connected to an acceptor type conjugated block (c‐A) via a nonconjugated and flexible bridge chain (nc‐B), also called a DBA type block copolymer, has been designed, synthesized, and characterized for potential cost‐effective and high‐efficiency optoelectronic applications such as solar cells. Specifically, D is a regio‐regular para‐2‐ethylhexyloxy‐substituted polyphenylenevinylene (or EH‐RO‐PPV), A is a regio‐regular polyphenylenevinylene with sulfone (SO2) acceptor moiety and a linear oxydecane (‐OC10H21) group substituted on every phenylene unit, and B contains an aliphatic chain with two or four methylene units. The size of each block can be controlled via synthetic feed ratio of the monomer and the terminator. The measured average molecular weights of D, A, and DBA based on gel permission chromatography are in good agreements with the molecular weights calculated using the monomer:terminator synthetic feed ratios. Preliminary optoelectronic device studies revealed an order of magnitude better improvement in photoelectric power conversion efficiency of DBA over the corresponding D/A blend under identical fabrication and testing conditions. Such improvements could be attributed to more efficient photo induced charge separation and charge transport in DBA versus in D/A blends. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1149–1160