Chromophores that generate singlet oxygen ( 1 O 2 ) in water are essential to developing noninvasive disease treatments using photodynamic therapy (PDT). A facile approach for formation of stable colloidal nanoparticles of 1 O 2 photosensitizers, which exhibit aggregation enhanced 1 O 2 generation in water toward applications as PDT agents, is reported. Chromophore encryption within a fuchsonarene macrocyclic scaffold insulates the photosensitizer from aggregation induced deactivation pathways, enabling a higher chromophore density than typical 1 O 2 generating nanoparticles. Aggregation enhanced 1 O 2 generation in water is observed, and variation in molecular structure allows for regulation of the physical properties of the nanoparticles which ultimately affects the 1 O 2 generation. In vitro activity and the ability of the particles to pass through the cell membrane into the cytoplasm is demonstrated using confocal fluorescence microscopy with HeLa cells. Photosensitizer encryption in rigid macrocycles, such as fuchsonarenes, offers new prospects for the production of biocompatible nanoarchitectures for applications involving 1 O 2 generation.

A new type of push-pull charge transfer complex, viz., a spiro-locked N-heterocycle-fused zinc porphyrin, ZnP-SQ, is shown to undergo excited state charge separation, which is enhanced by axial F- binding...

Photosynthetic mimicry of sequential ultrafast energy transfer followed by electron transfer upon fluoride binding to the oxoporphyrinogen cavity in a BODIPY–oxoporphyrinogen dyad is demonstrated.

Electron donor-acceptor (DA) hybrids comprised of single-wall carbon nanotubes (SWCNTs) are promising functional materials for light energy conversion. However, the DA hybrids built on SWCNTs have failed to reveal the much-sought long-lived charge separation (CS) due to the close proximity of the DA entities facilitating charge recombination. Here, we address this issue and report an elegant strategy to build multi-modular DA hybrids capable of producing longlived CS states. For this, a nano tweezer featuring Vshape configured BODIPY was synthesized to host SWCNTs of different diameters via π-stacking. Supported by spectral, electrochemical, and computational studies, the established energy scheme revealed the possibility of sequential electron transfer. Systematic pump-probe studies covering wide spatial and temporal scales provided evidence of CS from the initial 1 BODI-PY* ultimately resulting in C 60 *À -BODIPY-SWCNT * + CS states of lifetimes in the 20-microsecond range.

Meso-5,10,15,20-tetrakis-3,5-di-tert-butyl-4-oxocyclohexadienylideneporphyrinogen, OxP, is a versatile, highly colored chromophore with strong broad absorption in the visible range. It is derived from meso-5,10,15,20-tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)porphyrin by two-electron oxidation, and the OxP tetrapyrrole moiety exists in a saddle conformation. N-Alkylation of the OxP core nitrogen atoms can be used to functionalize the chromophore leading to a class of stable molecules with highly substituted peripheries. Substituted OxPs can act as singlet oxygen generators under light irradiation and the efficacy of this process is influenced by the multiplicity of N-substitution, and by the chemical identity of those substituents. Bromination of the macrocyclic [Formula: see text]-positions can also be used to control singlet oxygen generation by the relevant derivatives. We report the quantum yields of singlet oxygen generation for a series of differently substituted OxP derivatives whose metrics indicate that these compounds possess significant potential in the corresponding applications including photodynamic therapy, bacterial inactivation therapy, and organic transformations.