Solution-processed bulk heterojunction solar cells have experienced a remarkable acceleration in performances in the last two decades, reaching power conversion efficiencies above 10%. This impressive progress is the outcome of a simultaneous development of more advanced device architectures and of optimized semiconducting polymers. Several chemical approaches have been developed to fine-tune the optoelectronics and structural polymer parameters required to reach high efficiencies. Fluorination of the conjugated polymer backbone has appeared recently to be an especially promising approach for the development of efficient semiconducting polymers. As a matter of fact, most currently best-performing semiconducting polymers are using fluorine atoms in their conjugated backbone. In this review, we attempt to give an up-to-date overview of the latest results achieved on fluorinated polymers for solar cells and to highlight general polymer properties' evolution trends related to the fluorination of their conjugated backbone.

A unique metal-free intramolecular diamination of alkenes based on bromide catalysis is reported that uses only potassium bromide and sodium chlorite avoiding any use of transition metal. This unprecedented halide catalysis is of general applicability, uses economic reagents, can be conveniently up-scaled and proceeds under mild and selective conditions that surpass all conventional transition metals in scope.

F substituents & bulky alkyl side-chains for polymer:fullerene face-on orientation and high PV performances.

Boron dipyrromethene (BODIPY) and its derivatives are known to be efficient photon-harvesting chromophores. However, their study as active materials in bulk heterojunction (BHJ) solar cells is still scarce. In this study, the development of new synthetic ways to design original BODIPY-based dumbbell-shape molecules, including a first 2,3,5,6-tetravinyl aromatic BODIPY molecule, is reported. High fill factors can be obtained in BHJ solar cells when blended with a fullerene derivative, leading to a new record BODIPY-based power conversion efficiency of 5.8 %.

We demonstrate that the substitution of the thiophene by the thiazole heterocyclic compound as a weak electron-donor unit, in donor-acceptor alternating conjugated materials, allows a simultaneous downshift of both HOMO and LUMO levels while keeping the energy bandgap almost unchanged.

Unligated palladium(II) salts catalyze the oxidative diamination of acrylic esters to yield 2,3-diamino carboxylic esters. The reaction employs copper(II) bromide as oxidant and proceeds with good to excellent stereoselectivities and complete chemoselectivity. Preliminary mechanistic studies provide evidence for the involvement of a direct amination of the C--Pd bond in the alpha position relative to the ester group. This protocol significantly broadens the overall scope of the palladium-catalyzed diamination of alkenes and represents the first direct diamination of functionalized nonterminal substrates. The reaction yields readily protected 2,3-diamino acid derivatives, which can be considered as highly functionalized building blocks for subsequent synthesis. The use of one of these new diamination products as a suitable starting material in a short synthesis of the alkaloid absouline is demonstrated as an example.

Positive impacts on the PCE by using thiazole instead of thiophene in soluble electron-donor small molecules for OPV.

Homogeneous palladium catalysis enables a novel intermolecular regioselective diamination of allylic ethers, which offers a convenient entry into 1,2,3-trisubstituted products. These represent suitable building blocks with differently protected nitrogen atoms for subsequent synthetic application.