BODIPY-Based Molecules for Biomedical Applications.

BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) derivatives have attracted attention as probes in applications like imaging and sensing due to their unique properties like (1) strong absorption and emission in the visible and near-infrared regions of the electromagnetic spectrum, (2) strong fluorescence and (3) supreme photostability. They have also been employed in areas like photodynamic therapy. Over the last decade, BODIPY-based molecules have even emerged as candidates for cancer treatments.

4nπ Stable Multitasking Azapentacene: Acidochromism, Hole Mobility, and Visible Light Photoresponse.

Herein, we describe the synthesis, characterization, and optoelectronic investigation of a stable 4nπ dihydrotetraazapentacene derivative. The neutral dihydrotetraazapentacene contains a 24π-conjugated -heteroacene core with two phenyl pendants appended thereof. The exceptional stability of this formally antiaromatic π-system is attributed to the fused dihydropyrazine ring, which has ethenamine (enamine) conjugations, and hence, the π-electrons delocalize over the nearly planar azapentacene core to endow with a global aromatic characteristic.

Pt nanoparticles coupled with perylene-based small molecule deposited on Ti self-doped TiO nanorods-An inorganic/organic type-II nanoheterostructure for efficient visible-light photoelectrochemical water oxidation.

In the work reported in this article, we have coupled Ti-self-doped TiO nanorods (NRs) with a newly synthesized tetrathiophene coupled perylene-based molecule (tThTMP) to form type-II inorganic/organic nanoheterostructures (NHs) for visible-light-driven water oxidation. The small organic molecule helps in better utilizing a wide range of the visible light spectrum, facilitates a faster delocalization of the photogenerated carriers at the inorganic/organic heterojunction, and exhibits improved photoelectrochemical performances. We have further decorated the NHs with platinum nanoparticles (NPs).

Polycyclic Arene-Fused Selenophenes via Site Selective Selenocyclization of Arylethynyl Substituted Polycyclic Arenes.

Arene-fused selenophenes were synthesized by a redox neutral process from arylethynyl substituted polycyclic arenes using selenium powder in refluxing -methyl-2-pyrrolidone (NMP) with the assistance of the residual water in NMP as a catalytic proton source. The site-selective nature of this selenocyclization produces -alkenes as a competitive product, which is dependent on the π-electron donation ability of polycyclic arenes and the kind of arylethynyl group attached to it. DFT calculations were performed to understand the site selectivity in the selenophene formation reaction.

Localized surface plasmon-enhanced photoelectrochemical water oxidation by inorganic/organic nano-heterostructure comprising NDI-based D-A-D type small molecule.

This research article reports the visible-light-driven photoelectrochemical water oxidation performances of the plasmonic Au-Pd nanoparticle-decorated inorganic/organic nano-heterostructures (NHs)-B-TiO/NDIEHTh@Au-Pd. The inorganic constituent of the NHs consists of boron-doped TiO nanorods (NRs) grown on fluorine-doped tin oxide (FTO) coated glass substrate. The organic part (NDIEHTh) consists of an acceptor naphthalene diimide (NDI)-based donor-acceptor-donor (D-A-D) type small molecule, in which thiophene serves as the donor.

An unconventional route to an ambipolar azaheterocycle and its generated radical anion.

Herein we report the synthesis, characterization and application of an azaheterocycle 4 obtained via an unprecedented C-N coupling. The neutral azaheterocycle undergoes one-electron reduction to form an air-stable radical anion in situ, which provides added benefit towards operational stability of the device during n-type charge transport. The unusual stability of this radical anion is due to the fact that the fused cyclopentane ring upon reduction forms aromatic cyclopentadienyl anion, and the negative charge delocalizes over the nearly planar azaheterocycle core.

Boron difluoride formazanates with thiophene and 3,4-ethylenedioxythiophene capping and their electrochemical polymerization.

We report here the first example of BF2 formazanates with thiophene capping and their π-conjugated polymers in the form of electroactive uniform thin films by electrochemical polymerization. These new formazanates and their polymers possess panchromatic absorption with low lying frontier molecular orbitals. With small band gaps (1.

Radical-Cascade Avenue for 3,4-Fused-Ring-Substituted Thiophenes.

A single-step intramolecular radical cascade reaction of diynes and thioacetic acid in the presence of a catalytic amount of azobis(isobutyronitrile) as a radical initiator has been developed to synthesize thiophenes. This method allows easy and effective construction of a thiophene scaffold having 3,4-fused-ring substitution and unsubstituted 2,5-positions for further functionalization and polymerization. Using this method, derivatives of cyclopenta[ c]thiophene, 3,4-ethylenedioxythiophene, and thiophene-containing spirocyclic compound have been synthesized.