Lifetime Of State Research Articles

Effect of Tb2O3 in Mixed Alkali Borotellurie Glass for Green Emission and Scintillation-Efficiency

Present work aims to determine the effect of Tb2O3 in Mixed Alkali borotellurie glass. The glass was characterized by different techniques. Emission spectra has four intense and three-week transition at 486, 545, 590 and 620 nm because of transition from 5D4-level to the 7FJ-level (where, J =6, 5, 4, 3) and 5D4-level to the 7FJ (where, J = 0, 1 and 2) respectively. Integral-scintillation-efficiency of LNBT-Tb4 glass found to be 4.701% of BGO single crystal scintillator. It is observed that the lifetime of 5D4 state of the Tb3+-ions decreases for LNBT-Tb5 glass with increasing Tb2O3 (1.5 mol%) concentration. The CIE-coordinates and CCT value for LNBT are x = 0.30, y = 0.61 and fall in yellowish green region of CIE-diagram and 5989K. These results suggest the potential of prepared glass sample for green LEDs and display devices.

Mixed metal halide perovskite CsPb1-xSnxBr3 quantum dots: insight into photophysics from photoblinking studies.

Mixing different metal ions at the B site of ABX3 perovskites offers a promising approach for addressing challenges related to toxicity, stability and performance in optoelectronic applications. One such example is CsPb1-xSnxBr3 which addresses the toxicity issue posed by lead while allowing us to tune optoelectronic properties such as the band gap. In this work, nearly monodisperse CsPb1-xSnxBr3 quantum dots (QDs) were synthesized with variable Pb/Sn compositions, i.e. CsPbBr3, CsPb0.9Sn0.1Br3 and CsPb0.7Sn0.3Br3. The photoluminescence quantum yield (PLQY) of CsPb1-xSnxBr3 first increases for x = 0.1 and then decreases for x = 0.3 with respect to x = 0. Such an effect of Sn incorporation on the PLQY was investigated using photoblinking studies which revealed three levels of blinking statistics namely ON, GRAY and OFF. These results along with the excited state lifetime measurements enabled us to understand charge carrier dynamics in the CsPb1-xSnxBr3 QDs. Based on our findings, we propose that the photogenerated hot electrons of Sn enhance the PLQY by filling the trap states centered on Pb, which otherwise promote non-radiative relaxations in the Sn-free CsPbBr3. However, at higher Sn concentrations, non-radiative recombination becomes more pronounced, reducing the PLQY.

Toluidine blue O demethylated photoproducts as type II photosensitizers.

Toluidine blue O (TBO) is a type I-type II photosensitizer that has shown good efficacy and selectivity in antimicrobial and anticancer photodynamic therapy applications. However, its complex photochemistry with multiple photoproducts hinders its application as a photosensitizer. We have previously described the mechanism for photooxidative demethylation of TBO which in acetonitrile yields two main products: demethylated-TBO (d-TBO) and double-demethylated-TBO (dd-TBO). In the current work, we describe the photophysical properties of these two photoproducts. In acetonitrile and phosphate buffer, demethylation induces an hypsochromic shift in the absorption and fluorescence emission maxima. Fluorescence quantum yields increase slightly for the demethylated photoproducts, in agreement with the lengthening of the fluorescence lifetimes. Triplet excited states lifetimes in the presence of oxygen decreased slightly upon demethylation. However, the singlet oxygen quantum yield increased significantly reaching unity for the dd-TBO photoproduct. These results are interpreted in terms of the competing pathways of TBO photochemistry. For TBO, demethylation is the main pathway for deactivation of the excited state, while for d-TBO, demethylation and singlet oxygen generation are significant. For dd-TBO, singlet oxygen generation is the main deactivation pathway. Overall, TBO demethylated photoproducts demonstrate good potential as candidates for photodynamic therapy applications.

Periodic Light Modulations for Low-Cost Wide-Field Imaging of Luminescence Kinetics Under Ambient Light.

Imaging luminescence kinetics is invaluable in many fields, including biology and chemistry. However, the luminescence lifetime of most photo-activated states is in the low ns-µs range and its measurement requires adding costly image intensifiers to cameras to access the fast phenomena present. Here, the Rectified Imaging under Optical Modulation (RIOM) and Heterodyne Imaging under Optical Modulation (HIOM) protocols make this possible with standard low-cost cameras only, even under ambient light. RIOM and HIOM originate from a thorough theoretical analysis, which showed that modulated illumination of any reversibly photoactivable luminophore probed at high frequency generates components of the luminescence response that are detectable at low frequency: RIOM harnesses the mean luminescence response to modulated light at a single frequency, whereas HIOM exploits the luminescence response to modulated light at two close frequencies. When the luminophore behavior obeys a two-state model, the frequency dependence of the RIOM and HIOM observables can be used to extract a photoactivation time. In this work, their ability to retrieve maps of the luminescence lifetime of a reversibly photoswitchable protein, and phosphorescent microsensors are demonstrated. Where the luminophore does not obey a two-state model, RIOM and HIOM can still retrieve rich information, as here exemplified by the recovery of kinetic fingerprints of the physiological state of a plant.

A computational study on the effect of structural isomerism on the excited state lifetime and redox energetics of archetype iridium photoredox catalyst platforms [Ir(ppy)2(bpy)]+ and Ir(ppy)3.

This study investigates the impact of structural isomerism on the excited state lifetime and redox energetics of heteroleptic [Ir(ppy)2(bpy)]+ and homoleptic Ir(ppy)3 photoredox catalysts using ground-state and time-dependent density functional theory methods. While the ground- and excited-state reduction potentials differ only slightly among the isomers of these complexes, our findings reveal significant variations in the radiative and non-radiative decay rates of the reactivity-controlling triplet 3MLCT states of these closely related species. The observed differences in radiative decay rates could be traced back to variations in the transition dipole moment, vertical energy gaps, and spin-orbit coupling of the isomers. In [Ir(ppy)2(bpy)]+, transition dipole moment differences play a significant role in controlling the relative lifetime of the triplet states, which we rationalized by a vectorial analysis of permanent dipole moments of the ground and excited states. Regarding the two isomers of Ir(ppy)3, changes in radiative decay rates were primarily attributed to variations in vertical energy gaps and intensity borrowing from other singlet-singlet transitions driven by spin-orbit coupling. Non-radiative decay variations were assessed in terms of differences in reorganization energies, adiabatic energy gap, and spin-orbit coupling. For both complexes, reorganization energies associated with low-energy molecular vibrations and metal-ligand bond length changes following the de-excitation process were major contributors. These insights provide a deeper understanding of how molecular design can be leveraged to optimize the performance of iridium-based photoredox catalysts, potentially guiding the development of more efficient catalytic systems for future applications.

Photodissociation of : A Non-Adiabatic Dynamics Investigation.

Carbonyl complexes of metals with an α-diimine ligand exhibit both emission and ligand-selective photodissociation from MLCT states. Studying this photodissociative mechanism is challenging for experimental approaches due to an ultrafast femtosecond timescale and spectral overlap of multiple photoproducts. The photochemistry of a prototypical system is investigated with non-adiabatic dynamic simulations. Obtained 86 fs lifetime of the bright state and 13% quantum yield are in good agreement with experimental data. The present simulations suggest a ballistic mechanism of photodissociation, which is irrespective of the occupied electronic state. This is in contrast to the previously established mechanism of competitive intersystem crossing and dissociation. Selectivity of axial photodissociation is shown to be caused by the absence of an avoided crossing in the equatorial direction.

Dynamic Phosphorescence Behavior of Carbene-Metal-Amide Complexes from the Perspective of Excited State Modulation.

Carbene-metal-amide (CMA) complexes have diverse applications in luminescence, imaging and sensing. In this study, we designed and synthesized a series of CMA complexes, which were subsequently doped into a PMMA host. These materials demonstrate light-induced dynamic phosphorescence, attributed to their long intrinsic triplet state lifetime (τP,int, in the μs-ms scale), high intersystem crossing (ISC) rate constant (kISC, up to 107 s-1), and bright phosphorescence. The extended τP,int, and elevated kISC facilitate efficient sensitization of singlet oxygen (1O2) under light irradiation, which is rapidly consumed by the host material, creating a localized anaerobic environment conducive to bright phosphorescence emission. The Sn-T1 process exhibits a large spin-orbital coupling matrix element (SOCME) value, while the SOCME value between T1 and S0 is comparatively smaller, resulting in a large kISC and long τP,int, Computational results indicate that the hole-electron configuration in the lowest triplet state exhibits low contributions from gold. Based on the dynamic phosphorescence properties, an encryption material capable of achieving a "burn after reading" effect was developed. This work illustrates that those phosphorescent emitters with minimal heavy atom contribution can produce dynamic phosphorescent phenomena, providing a novel strategy for designing stimuli-responsive phosphorescent materials.

Excited state dynamics of azanaphthalenes reveal opportunities for the rational design of photoactive molecules

Various photoactive molecules contain motifs built on aza-aromatic heterocycles, although a detailed understanding of the excited state photophysics and photochemistry in such systems is not fully developed. To help address this issue, the non-adiabatic dynamics operating in azanaphthalenes under hexane solvation was studied following 267 nm excitation using ultrafast transient absorption spectroscopy. Specifically, the species quinoline, isoquinoline, quinazoline, quinoxaline, 1,6-naphthyridine, and 1,8-naphthyridine were investigated, providing a systematic variation in the relative positioning of nitrogen heteroatom centres within a bicyclic aromatic structure. Our results indicate considerable differences in excited state lifetimes, and in the propensity for intersystem crossing vs internal conversion across the molecular series. The overall pattern of behaviour can be explained in terms of potential energy barriers and spin-orbit coupling effects, as demonstrated by extensive quantum chemistry calculations undertaken at the SCS-ADC(2) level of theory. The fact that quantum chemistry calculations can achieve such detailed and nuanced agreement with experimental data across a full set of six molecules exhibiting subtle variations in their composition provides an excellent example of the current state-of-the-art and is indicative of future opportunities for rational design of photoactive molecules.

Synthesis, Structure, Spectral and Electrochemical Properties of 5,6,7,9,10,11‐Hexaaryl Substituted Meso‐(p‐Tolyl) 3‐Pyrrolyl BODIPYs

AbstractHexabrominated meso‐(p‐tolyl) 3‐pyrrolyl BODIPY was regioselectively synthesized by treating meso‐(p‐tolyl) 3‐pyrrolyl BODIPY with eight equivalents of Br2 in CH2Cl2 under inert atmosphere at room temperature. Five different 5,6,7,9,10,11‐hexaarylated meso‐(p‐tolyl) 3‐pyrrolyl BODIPYs were synthesized by treating 5,6,7,9,10,11‐hexabromo meso‐(p‐tolyl) 3‐pyrrolyl BODIPY with various boronic acids under Suzuki coupling conditions. The X‐ray structure obtained for hexabromo and hexaarylated 3‐pyrrolyl BODIPYs showed slightly distorted structures. Absorption spectral studies revealed that the absorption bands in hexabromo and hexaarylated 3‐pyrrolyl BODIPYs were bathochromically shifted compared to 3‐pyrrolyl BODIPY. The hexabromo 3‐pyrrolyl BODIPY was less fluorescent due to presence of heavy halogens whereas the hexaarylated 3‐pyrrolyl BODIPYs emits moderately in the region of 687–736 nm with quantum yields in the range of 0.18–0.30 and singlet state lifetimes in 2.99–4.50 ns range. The electrochemical studies revealed that hexabrominated 3‐pyrrolyl BODIPY undergo easier reduction compared to 3‐pyrrolyl BODIPY. The hexaarylated 3‐pyrrolyl BODIPYs showed one reversible/quasi‐reversible oxidation and one reversible reduction and their redox behaviour depends on the type of electron donating or electron withdrawing substituents present at the pyrrole carbons. DFT/TD‐DFT studies were in agreement with the experimental results. Group webpage: https://ravikanthlab.wixsite.com/mysite/

Leveraging Intramolecular π-Stacking to Access an Exceptionally Long-Lived 3MC Excited State in an Fe(II) Carbene Complex.

The ability to manipulate excited-state decay cascades using molecular structure is essential to the application of abundant-metal photosensitizers and chromophores. Ligand design has yielded some spectacular results elongating charge-transfer excited state lifetimes of Fe(II) coordination complexes, but triplet metal-centered (3MC) excited states─recently demonstrated to be critical to the photoactivity of isoelectronic Co(III) polypyridyls─have to date remained elusive, with temporally isolable examples limited to the picosecond regime. With this report, we show how strong-field donors and intramolecular π-stacking can conspire to stabilize a long-lived 3MC excited state for a remarkable 4.1 ± 0.3 ns in fluid solution at ambient temperature. Analysis of variable-temperature time-resolved absorption data using theoretical models ranging from Arrhenius to semiclassical Marcus theory, combined with computational modeling and X-ray crystallography, reveal a Jahn-Teller stabilized excited state with a high activation barrier for ground-state recovery. The net result is a chromophore with a 3MC excited-state lifetime that is orders of magnitude longer than anything yet observed for an Fe(II) complex.

Robust dioxin-linked metallophthalocyanine tbo topology covalent organic frameworks and their photocatalytic properties.

Constructing 3D functional covalent organic frameworks (COFs) with both robust linkage and planar macrocycle building blocks still remains a challenge due to the difficulty in adjusting both the crystallinity and the dominant 2D structures. In addition, it is also challenging to selectively convert inert C(sp3)-H bonds into value-added chemicals. Herein, robust 3D COFs, USTB-28-M (M=Co, Ni, Cu), have been polymerized from the nucleophilic aromatic substitution reaction of D 3h-symmetric 2,3,6,7,14,15-hexahydroxyltriptycene with D 4h-symmetric hexadecafluorophthalocyanine (MPcF16) under solvothermal conditions. These chemically stable dioxin-linked COFs show isostructural tbo topology made up of three kinds of polyhedron subunits, exhibiting high Brunauer-Emmett-Teller surface areas of ≤1477 m2 g-1. In particular, the multiple polyhedron subunits in USTB-28-M could trap N-hydroxyphthalimide at their corners for easily forming stable phthalimide-N-oxyl radicals under visible-light irradiation. The generated radicals efficiently promote the aerobic oxidation of alkyl benzenes with an inert C(sp3)-H bond into various ketones. Among the three investigated COFs, the USTB-28-Co radical initiator exhibits the best photocatalytic oxidation activity, converting ethylbenzene into acetophenone with a turnover frequency of 63 h-1, which is much higher than those of the monomer CoPcF16 (8 h-1) and 2D dioxin-linked counterparts (13 h-1). This is due to the much prolonged lifetime of the excited state for USTB-28-Co based on the femtosecond transient absorption result. The present work not only presents 3D functional COFs with robust connection and permanent porosity, but also illustrates the uniqueness of porous structures of 3D COFs for high-performance photocatalysis.

Mutational interference with oligomerization properties of OCP-related apo- and holoproteins studied by analytical ultracentrifugation.

In this study, the oligomerization pattern of apo- and holoforms of the Orange Carotenoid Protein (OCP) was examined under different conditions such as photoactivation state, concentration, and carotenoid embedment using analytical ultracentrifugation. Furthermore, studies were conducted on OCP constructs carrying point mutations of amino acid residues affecting OCP oligomerization. Our findings reveal that the concentration-dependent dimerization of dark-adapted OCP holoprotein from Synechocystis sp. PCC 6803 can be effectively prevented by the R27L mutation in the OCP-NTD. By introducing the E258R mutation (also in conjunction with R27L) into the OCP-CTD, monomeric OCP apoprotein can be obtained. Additionally, the holoprotein of the dark-adapted OCP-R27L/E258R variant was monomeric, and, supported by size-exclusion chromatography experiments, the photoactivated form of the OCP-R27L/E258R variant was monomeric as well. This variant, which does not oligomerize in either photocycle state, returns from the photoactivated to the dark-adapted state at a significantly faster rate than the OCP wild-type and the R27L mutant thereof. These observations also highlight the crucial interdependence between OCP dimerization in both photocycle states, the lifetime of the photoactive state of OCP, and the kinetics of the OCP photocycle.

Correlating photochemical H2 production and excited state lifetimes of heterostructured and doped ZnCdS nanoparticles.

A variety of ZnCdS-based semiconductor nanoparticle heterostructures with extended exciton lifetimes were synthesized to enhance the efficacy of photocatalytic hydrogen production in water. Specifically, doped nanoparticles (NPs), as well as core/shell NPs with and without palladium and platinum co-catalysts, were solubilized into water using various methods to assess their efficacy for solar H2 fuel synthesis. The best results were obtained with low bandgap ZnCdS cores and ZnCdS/ZnS core/shell NPs with palladium co-catalysts. The results, augmented with DFT and tight binding electronic structure calculations, revealed the importance of exciton charge carrier separation via tunneling. While the systems studied here were photocatalytically active, they nonetheless lagged behind the quantum efficiency observed from "gold standard" CdSe/CdS·Pt dot-in-rod nanoparticles as evident from quantum efficiencies that were estimated to be 0.5 → 2%.

Increasing excited state lifetimes of Cu(i) coordination complexes via strategic surface binding

Molecules undergo a structural change to minimize the energy of excited states generated via external stimuli such as light.

Tailoring the photoluminescence of AIE-type gold nanoclusters via biomineralization-inspired polymorphism.

Tailoring the aggregation-induced emission (AIE) characteristics of well-defined metal nanoclusters (MNCs) is highly sought after for numerous practical applications. Studies have primarily focused on assembling AIE-type MNCs using monomorphic molecules. Achieving polymorphic assemblies, with different molecular arrangements could provide valuable insights into the role of external molecular matrices on the photoluminescence (PL) behaviour of these NCs. In this study, by mimicking biomineralization, we successfully embedded AIE-type Au22SG18 NCs within different polymorphic environments of CaCO3. Upon incorporation into CaCO3 matrices such as, calcite, vaterite and a mixture of both, the PL was enhanced in all the inorganic composites accompanied by a significant blue shift. In the metastable vaterite matrix, Au22SG18 NCs exhibited the highest blue shift in the PL spectrum while in the stable crystalline matrix of calcite, the NCs showed the highest PL intensity as well as excited state lifetime. Time-resolved spectroscopic and single-molecule Raman studies revealed that variations in the PL of NCs are linked to the stability of their polymorphic structures, progressing from vaterite to a vaterite/calcite mixture, and finally to calcite. These findings shed light on the crucial role of external molecular arrangement in the AIE behaviour of MNCs.

Luminescence sensing of narcotic drugs by a BSA protein stabilized AuAgCd trimetallic nanocluster

A luminescent trimetiallic nanocluster (NCs) stabilized by BSA protein (AuAgCd-BSA) was synthesized along with its mono and bimetallic counterparts (Au-BSA and AuAg-BSA). The detail characterization and comparative luminescence sensing performance for narcotic drugs and psychotropic substance (amphetamine, morphine) were performed for these three clusters. It was revealed that the trimetallic cluster can detect amphetamine and morphine drugs through turn on luminescence response. The calculated binding constants are found to be Ka = 5.86× 103 M−1 for Amphetamine and 3.75× 103 M−1 for Morphine by using Benesi-Hildebrand equation. The trimetallic cluster also showed selective turn off luminescence response in presence of mercury (Hg2+) ions. The origin of the enhanced PL responses in presence of amphetamine and morphine was further investigated by exploring the PL lifetime decay studies, which reveals that larger excited state lifetime (in μs timescale) value of pristine cluster remain unchanged upon incremental addition of drugs leading to longer interaction time with the analytes. Thus, the present work undoubtedly establishes the superior drug sensing behaviour of AuAgCd-BSA tri-metallic NCs as compared to its mono-metallic and bi-metallic counterparts and open further emphasis on exploring luminescence-based sensing of narcotic drugs which has great forensic relevance.

Nonadiabatic ab initio chemical reaction dynamics for the photoisomerization reaction of 3,5-dimethylisoxazole via the S1 electronic state.

Nonadiabatic ab initio molecular dynamics simulations were performed to explore the photoisomerization pathway from isoxazole (iso-OXA) to oxazole (OXA), considering four electronic states. The XMS-CASPT2 and SA4-CASSCF theories were employed to describe these electronic structures, which were caused by 12 electrons in 11 orbitals with the cc-pVDZ + sp diffuse basis set; the Gaussian s- and p-type diffuse functions were extracted from Dunning's aug-cc-pVDZ function. The potential energy and its gradient at each time step were computed on-the-fly at these levels in the time evolution of the classical trajectory. When the two electronic states were close to each other, the trajectory surface hopping (TSH) judgment between the two adjacent states was carried out by the anteater procedure based on the Zhu-Nakamura formula (ZN-TSH). The two different excited state lifetimes were found to exist in the first electronic state (S1), estimated at 10.77 and 119.81 fs. Upon photoexcitation, the N-O bond breaks and energetically relaxes to the ground state (S0). In the pathway leading to the main product, azirine formation, the 5-membered ring retains a planar structure while undergoing a non-adiabatic transition with an increasing N-O bond distance. Furthermore, it was verified that a 1,2-shift takes place in the pathway that results in the production of ketenimine, causing a nonadiabatic transition.

Decoding the excited-state dynamics of carbonyl-containing carotenoids: Insights from the Ind series.

Carotenoids are naturally occurring pigments essential for both light-harvesting and photoprotection in photosynthetic processes. Among these, carbonyl-containing carotenoids exhibit distinctive excited state properties due to the presence of intramolecular charge transfer (ICT) in their excited states. In this study, we synthesized a novel family of carotenoid analogs with varying numbers of conjugated double bonds, denoted as the Ind series, and conducted femtosecond pump-probe spectroscopy on these molecules in both acetone and n-hexane. The objective was to elucidate how the excited-state dynamics depend on the conjugation length. The spectroscopic characterization of the Ind series revealed several unique features: the observation of stimulated emission from the 1Ag-/ICT state, the emergence of the 1nπ∗ state, triplet state formation mediated by the 1nπ∗ state, and an anomalous solvent dependence of the 1Ag-/ICT state lifetimes. The relationship between conjugation length and excited state dynamics, as well as the ICT character of the Ind series, are thoroughly discussed.

Optoelectronic Properties and Fluorescence Lifetime Imaging Application of Donor-Acceptor Dyads Derived From 2,6-DicarboxyBODIPY.

Donor-acceptor BODIPY dyads, functionalized at the 2 and 6 positions with benzyl ester (BDP-DE) or carboxylic acid (BDP-DA) groups, were synthesized and characterized for their optoelectronic properties. The introduction of carbonyl groups increased the reduction potential of the BODIPY core by 0.15-0.4 eV compared to alkyl-substituted analogs. These dyads exhibited efficient intramolecular charge separation and triplet state formation through spin-orbit charge transfer intersystem crossing (SOCT-ISC), achieving singlet oxygen quantum yields of up to 92%, modulated by solvent polarity. The fluorescence and singlet oxygen generation of BDP-DAs depended on the ionization state of the carboxylic groups. Complexation of BDP-DAs with bovine serum albumin (BSA) significantly extended their excited state lifetimes, as shown by time-resolved fluorescence measurements. Fluorescence lifetime imaging microscopy (FLIM) studies in human colorectal carcinoma (HCT116) cells and pig small intestinal organoids (enteroids) revealed subcellular localization patterns. Specifically, the diacid with a dimethoxyphenyl group (DA1) displayed longer lifetimes in lipid-droplet-like structures, while the diacid containing a meso-anthracenyl group (DA2) formed distinct 'islands' in cell monolayers, exhibiting a lifetime gradient. These results underscore the potential of donor-acceptor BODIPYs as fluorescent probes for distinguishing cellular environments.

Machine Learning‐Corrected Simplified Time‐Dependent DFT for Systems With Inverted Single‐t‐o‐Triplet Gaps of Interest for Photocatalytic Water Splitting

ABSTRACTHydrogen gas (H2) can be produced via entirely solar‐driven photocatalytic water splitting (PWS). A promising set of organic materials for facilitating PWS are the so‐called inverted singlet‐triplet, INVEST, materials. Inversion of the singlet (S1) and triplet (T1) energies reduces the population of triplet states, which are otherwise destructive under photocatalytic conditions. Moreover, when INVEST materials possess dark S1 states, the excited state lifetimes are maximized, facilitating energy transfer to split water. In the context of solar‐driven processes, it is also desirable that these INVEST materials absorb near the solar maximum. Many aza‐triangulenes possess the desired INVEST property, making it beneficial to describe an approach for systematically and efficiently predicting the INVEST property as well as properties that make for efficient photocatalytic water splitting, while exploring the large chemical space of the aza‐triangulenes. Here, we utilize machine learning to generate post hoc corrections to simplified Tamm–Dancoff approximation density functional theory (sTDA‐DFT) for singlet and triplet excitation energies that are within 28–50 meV of second‐order algebraic diagrammatic construction, ADC(2), as well as the singlet‐to‐triplet, ΔES1T1, gaps of PWS systems. Our Δ‐ML model is able to recall 85% of the systems identified by ADC(2) as candidates for PWS. Further, with a modest database of ADC(2) excitation energies of 4025 aza‐triangulenes, we identified 78 molecules suitable for entirely solar‐driven PWS.