π-Conjugated Materials Derived From Boron-Chalcogenophene Combination. A Brief Description of Synthetic Routes and Optoelectronic Applications

Palladium-Catalyzed ipso-Borylation of Aryl Halides Promoted by Lewis Acid-Mediated Electrophilic Activation of Aryl(halo)palladium(II) Complex

Palladium-catalyzed ipso-borylation of aryl halides, well-known as Miyaura borylation, is one of the reliable synthetic methods for organoborons. This reaction involves base-mediated nucleophilic activation of diboron that enables transmetalation of an aryl(halo)palladium(II) intermediate with a diboron. As an alternative, herein, we have established Lewis acid-mediated conditions for borylating (pseudo)haloarenes that require no external base. The electrophilic activation of the aryl(halo)palladium(II) intermediate via dehalogenation with Lewis acidic zinc complexes promotes the borylation.

Impact of end-capped modification of MO-IDT based non-fullerene small molecule acceptors to improve the photovoltaic properties of organic solar cells

Density functional theory, along with its time dependent computational approach were employed in order to fine tune the photovoltaic attributes along with the efficiency of the MO-IDIC-2F molecule. Thus, five new molecules were designed by substitution of the different notable acceptor fragments in the MO-IDIC-2F molecule, along with the addition of the "[1, 2, 5] thiadiazolo[3,4-d] pyridazine" spacer moieties between donor core and newly substituted acceptor groups. In this research work, various photovoltaic properties, which could affect the efficiency of an organic chromophores, such as bandgap, oscillator strength, dipole moment, binding energy, light-harvesting efficiency, etc. were studied. All the newly proposed molecules demonstrated significantly improved outcomes in comparison to that of the reference molecule, in their absorption spectrum, excitation, as well as binding energy values, etc. In order to confirm the results of optoelectronic properties, density of states, transition density matrix, and electrostatic potential analyses of molecules were also performed, which supported our computational findings. All of the results confirmed the high potential of all the newly proposed molecules for the development of improved OSCs.

Metal-catalysed C-H bond activation and borylation

Transition metal-catalysed direct borylation of hydrocarbons via C-H bond activation has received a remarkable level of attention as a popular reaction in the synthesis of organoboron compounds owing to their synthetic versatility. While controlling the site-selectivity was one of the most challenging issues in these C-H borylation reactions, enormous efforts of several research groups proved instrumental in dealing with selectivity issues that presently reached an impressive level for both proximal and distal C-H bond borylation reactions. For example, in the case of ortho C-H bond borylation reactions, innovative methodologies have been developed either by the modification of the directing groups attached with the substrates or by creating new catalytic systems via the design of new ligand frameworks. Whereas meta and para selective C-H borylations remained a formidable challenge, numerous innovative concepts have been developed within a very short period of time by the development of new catalytic systems with the employment of various noncovalent interactions. Moreover, significant advancements have occurred for aliphatic C(sp³)-H borylations as well as enantioselective borylations. In this review article, we aim to discuss and summarize the different approaches and findings related to the development of directed proximal ortho, distal meta/para, aliphatic (racemic and enantioselective) borylation reactions since 2014. Additionally, considering the C-H borylation reaction as one of the most important mainstream reactions, various applications of this C-H borylation reaction toward the synthesis of natural products, therapeutics, and applications in materials chemistry will be summarized in the last part of this review article.

Fluorescent small molecules with alternating triarylamine-substituted selenophenothiophene and triarylborane: synthesis, photophysical properties and anion sensing studies

Two novel D-π-A fluorophores based on selenopheno[3,2-b]thiophene, possessing triphenylamine and 4,4'-dimethoxytriphenylamine units as donors and dimesitylborane as an acceptor, linked through a π-conjugated thiophene spacer (BTPAST and BOMeTPAST, respectively) were synthesized. Their photophysical properties were investigated in both solution and the state of aggregation and compared to those of their corresponding donor parts, having no dimesitylborane units (TPAST and OMeTPAST). All the compounds displayed large Stokes shifts between 100 and 140 nm with positive solvatochromism in solvents having different polarities. While BTPAST displayed both aggregation induced emission (AIE) and twisted intramolecular charge transfer (TICT) characteristics, the others preponderated with TICT effects. The sensing abilities of BTPAST and BOMeTPAST towards different anions were studied. Both exhibited chromogenic and fluorogenic responses to small anions such as fluoride and cyanide, for which the detection limits were found to be 0.12 and 2.43 ppm with BTPAST and 0.59 and 0.92 ppm with BOMeTPAST, respectively. These results provide guidance for the development of novel fused selenophenothiophene sensors in the field of anion sensing.