Copper(I) thiocyanate (CuSCN) is rising to prominence as a hole‐transporting semiconductor in various opto/electronic applications. Its unique combination of good hole mobility, high optical transparency, and solution‐processability renders it a promising hole‐transport layer for solar cells and p‐type channel in thin‐film transistors. CuSCN is typically deposited from sulfide‐based solutions with diethyl sulfide (DES) being the most widely used. However, little is known regarding the effects of DES on CuSCN films despite the fact that DES can coordinate with Cu(I) and result in a different coordination polymer having a distinct crystal structure when fully coordinated. Herein, the coordination of DES in CuSCN films is thoroughly investigated with a suite of characterization techniques as well as density functional theory. This study reveals that DES directly affects the microstructure of CuSCN by stabilizing the polar crystalline surfaces via the formation of strong coordination bonds. Furthermore, a simple antisolvent treatment is demonstrated to be effective at modifying the microstructure and morphology of CuSCN films. The treatment with tetrahydrofuran or acetone leads to uniform films consisting of CuSCN crystallites with high crystallinity and their surfaces passivated by DES molecules, resulting in an increase in the hole mobility from 0.01 to 0.05 cm2 V−1 s−1.

DFT (M06-L) calculations on the transition state for the 1,3-dipolar cycloadditions between substituted vinyl sulfones with sugar azide have been reported in conjunction with new experimental results, and the origin of reversal of regioselectivity has been revealed using a distortion/interaction model. This study provides the scientific justification for combining organic azides with two different types of vinyl sulfones for the preparation of 1,5-disubstituted 1,2,3-triazoles and 1,4-disubstituted triazolyl esters under metal-free conditions.

Finding strategies for effective charge separation is a prerequisite for realizing efficient solar energy conversion in photovoltaic and photocatalytic devices. Porphyrinoids, including porphyrins and related macrocycles such as phthalocyanines and corroles, are versatile ligands that can accommodate a single metal atom for most metal ions, and their photophysical and electrochemical properties can be tuned by the metal atom in the cavity. Herein, we evaluated the photovoltaic properties of the dye-sensitized solar cells (DSSCs) based on AuIII-, ReVO-, and OsVIN-corroles with COOH anchoring groups at the para- and meta-positions of the meso-phenyl groups. The DSSCs based on AuIII-corroles exhibited a power conversion efficiency (PCE) of 4.2%, which is remarkably higher than those for the ReVO- and OsVIN-corroles. Femtosecond time-resolved transient absorption measurements have shown that the electron injection from the excited singlet state competes with intersystem crossing, and that intersystem crossing for AuIII-corroles is slower than those for ReVO- and OsVIN-corroles. Consequently, the high incident photon-to-current efficiencies and resultant short-circuit current densities and PCEs for AuIII-corroles are attributed to the high electron injection efficiencies owing to the slower intersystem crossing than ReVO- and OsVIN-corroles. In addition, the higher PCE for a AuIII-corrole with a meta-COOH group (4.2%) as opposed to a para-COOH group (3.4%) is explained by the stronger Au–TiO2 interactions supported by XPS measurements and theoretical calculations. These results imply that both the substituents and the metal ion have a large influence on the photovoltaic performances. Overall, DSSCs based on the AuIII-corroles were found to exhibit the highest photovoltaic performance among corrole-based DSSCs.

A new 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based probe molecule (L) is synthesized for specific binding to Hg ion in physiological condition with an associated luminescence ON response in the near-IR region of the spectrum. Appropriate functionalization in the 5-position of each of two pyrrole moieties with styryl functionality in a BODIPY core helped us in achieving the extended conjugation and a facile intramolecular charge transfer transition with a narrow energy gap for frontier orbitals. This accounted for a poor emission quantum yield for the probe molecule L. Binding to Hg helped in interrupting the facile intramolecular charge transfer (ICT) process that was initially operational for L. This resulted in a hypsochromic shift of absorption band and a turn-on luminescence response with λ of 650 nm on specific binding to Hg. Observed spectral changes are rationalized based on quantum chemical calculations. Interestingly, this reagent is found to be localized preferentially in the mitochondria of the live human colon cancer (Hct116) cells. Mitochondria is one of the major targets for localization of Hg, which actually decreases the mitochondrial membrane potential and modifies various proteins having sulfudryl functionality(ies) to cause cell apoptosis. Considering these, ability of the present reagent to specifically recognize Hg in the mitochondrial region of the live Hct116 cells has significance.