A novel BODIPY derivative was designed for biomedical applications. Its mono-quaternized structure ensured its water-solubility and suitable amphiphilicity. Showing no singlet oxygen generation to avoid damage to healthy cells, this new derivative proved to be an extremely promising antimicrobial agent, with activity equal or superior to ampicillin against MRS Staphylococcus strains with no short-term resistance issue. Its activity against MSS Staphylococcus strains was largely superior to those of ampicillin and reached the activity of vancomycin against MSS S. epidermidis. This latter result is in particular extremely promising for the treatment of hospital-acquired infections. Also the fluorescence properties of BODIPY allowed imaging of the uptake.

We herein report a new highly efficient green emissive hot-exciton molecule, 1,4-bis((4′-diphenylamino-3-cyano-[1,1′-biphenyl]-4-yl)ethynyl)-2,5-bis(2-ethylhexyloxy)benzene (2EHO-TPA-CNPE) that consists of an extended D′–π′–A–π–D–π–A–π′–D′ molecular π-system with diphenylamino end units (D′) and ethynylene/phenylene spacers (π/π′). The new molecule exhibits high photoluminescence (PL) quantum efficiencies (Φ_PL = 0.95 (solution) and 0.45 (spin-coated neat thin-film)), and a strong PL solvatochromic behavior revealing significant changes in excited state energies/characteristics (locally excited (LE) → hybridized local and charge transfer (HLCT) → charge-transfer (CT)) depending on solvent polarity. Highly efficient (radiative exciton yield (η_r) = 50–59% ≫ 25%) green-emitting OLEDs were fabricated in a conventional device architecture by employing (non-)doped thin-films reaching a maximum current efficiency (CE_max) of 12.0 cd A⁻¹ and a maximum external quantum efficiency (EQE_max) of 5.5%. The emission profile of the non-doped OLED has CIE 1976 (u′, v′) chromaticity coordinates of (0.10, 0.55) corresponding to a night vision imaging system (NVIS) compatible Green A region. 2EHO-TPA-CNPE-based OLED devices of industrial relevance were also fabricated by ink-jet printing the emissive layer and by fabricating an inverted architecture, which possessed respectable device performances of 2.4–6.1 cd A⁻¹. The solid-state solvation effect in OLED devices yields HLCT electronic behavior resulting in high η_r's, which is confirmed by TDDFT to originate from energetically/spatially favorable reverse intersystem crossings (RISCs) (T_2/3 → S₁). As a unique observation, delayed fluorescence due to this RISC was evident in the PL decay lifetime measurement with a ns-scale lifetime of ∼10 ns. These results clearly allow a better understanding of the structure–photophysical property–electroluminescence relationships in this new class of oligo(p-phenyleneethynylene)-based hot-exciton molecules, and it could open up new opportunities for high-performance solution-processed optoelectronic/sensing applications.

Asymmetric zinc phthalocyanine dyes bearing electron donating tert-butylsulfanyl or hexylsulfanyl groups and a carboxylic acid anchoring group that act as “push” and “pull”, respectively, have been designed, synthesized and used as sensitizers for dye-sensitized solar cells (DSSCs). Theoretical calculations of Gibbs free energy change performed with the B3LYP, HSE06 and M06 functionals show that there is not a unique trend but a preference by the 2-GT6-cs and 2-GT4-cs isomers as the most stable structures. Electronic absorption spectra calculated with time-dependent density functional theory (TD-DFT) (M06/6-311G(d,p)) in THF indicate that, taking as a reference GT6 isomers, a red-shift of the Q bands is produced for the GT4 isomers, with values up to 33 nm. Theoretical calculations show that the hexyl chains in GT4 are located along the molecular plane, but the tert-butyl moieties in GT6 are non-planar. Therefore, compared with the planar one, the non-planar compound shows both a slight blue shift in absorption and a lower tendency for dye aggregation. When the dyes were employed in DSSCs with chenodeoxycholic acid (CDCA) as a co-adsorbent, the power conversion efficiency (PCE) was obtained as 3.19% for GT4 and 3.08% for GT6 under full sunlight (AM 1.5, 100 mW cm⁻²) irradiation. This can be attributed to the higher dye loading of the DSSC sensitized with GT4. However, GT4 was considerably decomposed, while GT6 retained most of its initial optical properties after continuous sunlight exposure. This result demonstrates that the zinc phthalocyanine dye containing tert-butyl moieties shows excellent photostability.

A novel push–pull zinc phthalocyanine dye (KH1) containing 2,6-di- tert -butyl-4-methylphenoxy donor groups was synthesized for DSSCs. The DSSC based on the dye exhibited a PCE of 3.12%.