The rational molecular design of non-fullerene acceptors (NFAs) in organic solar cells (OSCs) can profoundly influence the photovoltaic (OPV) performance. To date, NFA fluorination has proven beneficial to cell performance. However, there is a lack of comprehensive understanding of how various fluorination modalities influence film morphology, carrier mobility, molecular packing, other structural properties, electronic structure, exciton separation, and charge transport, that determine ultimate cell efficiency. Here, we compare two types of end group (EG) fluorination patterns on Y6-based A-DAD-A cores, resulting in highly efficient NFAs: direct skeletal fluorination (BTF) and indirect trifluoromethyl fluorination (BTFM). These two patterns induce distinctive behaviors in the active layer blends with a chlorinated donor polymer D18-Cl and the additive, 1-chloronaphthalene, affording high PCE values of 17.30% (BTF + additive) and 17.10% (BTFM, no-additive). The BTFvs.BTFM OSC performance trends can be correlated with diffraction-derived differences in molecular packing. Density functional theory (DFT) reveals remarkably low internal reorganization energies and high electronic coupling between NFA dimers, greater and more numerous than in other NFAs reported to date, thus providing extended 3D charge transport networks in the thin film crystalline domains. Transient absorption spectroscopy reveals that hole transfer from the acceptor to the donor occurs in <300 fs and that photoexcited carriers persist for hundreds of ns in each blend film. The contrasting role of the additive in BTF and BTFM cells is further clarified by recombination dynamics analysis using in situ photocurrent and impedance spectroscopy. Overall, this work provides guidance for developing new NFAs via direct and indirect fluorination strategies for high efficiency OSCs.

A strategy is presented for the synthesis of dual-modality and theranostic silica (SiO₂ ) nanohybrids that exert excellent properties for drug delivery vehicles as well as optical and magnetic resonance imaging. SiO₂ nanohybrids are composed of CuInS₂ /ZnS quantum dots and magnetite nanocrystals, with an outside SiO₂ shell grafted with poly(ethyleneglycol) and amine groups to provide better biocompatibility and allow subsequent bioconjugation, respectively. The synthesized nanohybrids are of ultra-small size (diameter < 30 nm) and highly monodispersed and stable in aqueous suspension. In vitro results showed that the SiO₂ nanohybrids were efficiently taken up by the cells and localized in the intracellular vesicles, emitting strong fluorescence from the cytoplasm and nearby nucleus. It was also demonstrated that SiO₂ nanohybrids could be used as a new class of magnetic resonance imaging probes, demonstrating a high spin–spin (T₂) relaxivity (r₂ = 214 mM⁻¹ s⁻¹). The Pt(IV) anticancer drug, c,c,t-[Pt(NH₃)₂Cl₂(O₂CCH₂CH₂CO₂H)₂], was used as a model drug to attach to the surface of dual-modality SiO₂ nanohybrids by using n-ethyl-N′-(3-dimethylaminopropyl)carbodiimide and hydroxysuccinimide as the activating agents. The drug readily formed amide linkages with amines on the surface of the SiO₂ nanohybrids, resulting in Pt(IV)-conjugated SiO₂ nanohybrids. The results reveal that the Pt(IV)-conjugated SiO₂ nanohybrids show higher cytotoxicity than the free Pt(IV) anticancer drug, indicating the potential for using the obtained multifunctional SiO₂ nanohybrids simultaneously as highly effective dual-modality imaging probes for cancer diagnosis and chemotherapy.

The reactions between B₂F₄ and the platinum and iridium complexes [Pt(PPh₃)₂(η-C₂H₄)], [Pt(dppb)(η-C₂H₄)] [dppb = 1,4-bis(diphenylphosphino)butane] and trans-[IrCl(CO)(PPh₃)₂] afforded the difluoroboryl complexes cis-[Pt(BF₂)₂(PPh₃)₂], cis-[Pt(BF₂)₂(dppb)] and fac-[Ir(BF₂)₃(CO)(PPh₃)₂] respectively all of which have been characterised by X-ray crystallography. The isoelectronic platinum dppb nitrito complex cis-[Pt(NO₂)₂(dppb)] has also been prepared and structurally characterised.

Here, we report insights into the new recyclable catalyst 1, (DMAP·saccharin). The DMAP·saccharin-catalysed acylation of alcohols has been successfully carried out more than 8 times. Only 1 mol% of catalyst 1 efficiently promotes acylation with almost equimolar amounts of acid anhydrides, under both base-free and solvent-free conditions.