Ksenofontov, Alexander Andreevich

Lukanov M.M., Ksenofontova K.V., Kerner A.A., Ksenofontov A.A.

Makarov D.M., Ksenofontov A.A., Budkov Y.A.

Ksenofontov A.A., Berezin M.B., Bocharov P.S., Khodov I.A., Miloshevskaya O.V., Antina E.V.

The search for fluorophores with intense absorption and emission in the red region of the spectrum is an important task, as such compounds can be used in fluorescence imaging, providing high image resolution due to the deep penetration of low energy photons into tissues. In this paper, we present the results of the synthesis and photophysical characterization of a novel ms-benzimidazole-4,4′,5,5′-tetramethyldipyrromethene bis(difluoroborate) (BOIMPY) compound, which exhibits intensive absorption and emission in the long-wavelength region while maintaining high fluorescence quantum yields (up to 60%). Using DFT analysis, we investigated the geometry of BOIMPY in both ground and excited states and described the influence of the molecular structure on its practically relevant photophysical properties.

Guseva G.B., Eremeeva Y.V., Ksenofontov A.A., Antina E.V., Gilfanov I.R., Lisovskaya S.A., Trizna E.Y., Kayumov A.R., Babaeva O.B., Boichuk S.V., Dunaev P.D., Klochkov V.V., Rakhmatullin I.Z., Nikitina L.E.

Chervonova U.V., Bichan N.G., Ksenofontov A.A., Gruzdev M.S.

Lukanov M.M., Ksenofontov A.A.

Results are presented from developing a model for accurately predicting the wavelength of the absorption maximum of boron(III) dipyrromethenates (BODIPYs). The model is based on a graph neural network (GNN) and includes data for >2500 dyes of various natures. Statistical parameters of the model (MAE and R2) are 4 nm and 0.99 for the training set and 13.5 nm and 0.87 for the testing set. The developed model is available to the public in the GitHub repository ( https://github.com/lukanov-9b/Abs_model.git ).

Sherudillo A.S., Antina L.A., Kalinkina V.A., Kalyagin A.A., Ksenofontov A.A., Babaev V.M., Berezin M.В., Antina E.V.

Bumagina N.A., Ksenofontov A.A., Bocharov P.S., Antina E.V., Berezin M.B.

Multifunctional sensors are becoming increasingly important because a single such compound can be used to detect ions of two or more metals. We propose a 3,3′,4,4′,5,5′-hexamethyl-2,2′-dipyrromethene (HL) as multifunctional chemosensor for absorbance ratiometric detection of Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ ions, and fluorescent detection of Zn2+, Cd2+ ions. The influence of the nature of complexing ion and medium on the thermodynamic stability of the [ML2] complexes, chromophoric and fluorescent responses of complexation reactions was analyzed. The lgKo values of [ML2] formation processes range from 4.72 to 11.08 and, regardless of the medium nature, increase in similar sequences of complexing agents: Cd2+, Ni2+, Hg2+, Co2+, Zn2+, Cu2+ – in the c-hexane/propanol-1 (30:1, v/v) and Cd2+, Hg2+, Co2+, Zn2+ – in DMF. The maximum fluorescent response (I/Io = 100–150) was observed for the reaction of dipyrromethene with Zn2+ ions. The reaction of HL with Cd(AcO)2 is accompanied by a 10-fold increase in fluorescence. Depending on the nature of the metal ion being determined and the medium, the detection limit of M2+ ions reaches 5 × 10−9–5 × 10−8 mol/L. Test-systems as HL-doped cellulose tablets were developed for detecting trace amounts of Zn2+ and Cd2+ ions in aqueous solutions. The using 3,3′,4,4′,5,5′-hexamethyl-2,2′-dipyrromethene as a multifunctional chemosensor, both chromophore detection of Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ ions and "turn-on" fluorescent sensing trace amounts of Zn2+ and Cd2+ ions can be performed. Considering the significant differences in the chromophore-fluorescent characteristics of ligands and metal complexes, dipyrromethenes have great prospects for use in cation recognition.

Ksenofontova K.V., Shagurin A.Y., Molchanov E.E., Ksenofontov A.A., Sbytov D.A., Kalyamanova Y.E., Danilova E.A., Marfin Y.S.

AbstractTwo π‐extended derivatives of boron‐dipyrromethene (BODIPY) – unsymmetrical benzo[b]‐fused BODIPY 1 and symmetrical naptho[b]‐fused BODIPY 2 – were synthesized. Spectroscopic and photophysical properties of the synthesized fluorescent dyes were investigated in various organic media. Both BODIPY 1 and BODIPY 2 distinguished by bathochromically shifted absorption and emission bands compared to their non‐fused derivatives, while possessing green (526–543 nm) and red (664–708 nm) absorbance and fluorescence, respectively. Spectral characteristics of the investigated fluorescent dyes were found to be weakly depended on solvent polarizability in case of BODIPY 1 and greatly influenced by both solvent polarizability and dipolarity in case of BODIPY 2. Quantum chemical calculations were used to clarify the relationships between geometry/electronic structure and spectral properties/solvatochromic behavior of BODIPY 1 and BODIPY 2.

Antina L.A., Kalinkina V.A., Sherudillo A.S., Kalyagin A.A., Lukanov M.M., Ksenofontov A.A., Berezin M.B., Antina E.V.

Photosensitizers (PS) with optimal photophysical characteristics are necessary for an integrated approach to the diagnosis and treatment of diseases various types using photodynamic therapy (PDT). This study explores the potential of СН(R)-bis(BODIPY) dyes 1–4, 3a, and 3b as heavy-atom-free рhotosensitizers. A detailed computer study of СН(R)-bis(BODIPY) dyes demonstrates the role of SOCT-ISC (photoinduced spin–orbital charge transfer enhanced ISC) in the 4,4-CH2-bis(BODIPY) 4 photosensitizing properties implementation. The design strategies of a novel water-soluble polymer nanophotosensitizes 4-NPs, based on a dimeric dye 4 and a biocompatible amphiphilic block copolymer Pluronic® F127 are presented. A comparative analysis of dye 4 solubilization efficiency and its spectral properties in the composition of supramolecular 4-NP systems obtained by different techniques, as well as the sizes of the resulting nanostructures, was carried out.

Bumagina N.A., Krasovskaya Z.S., Ksenofontov A.A., Antina E.V., Berezin M.B.

A wide range of dipyrromethenes (17 objects) with different nature, number, and attachment positions of alkyl, aryl, and meso-aza substituents was synthesized, and the effect of molecular structure features on their spectral properties was analyzed. It is shown that, chromophores absorb in a wide spectral range from ∼ 420 to ∼ 600 nm due to the structural modification of the dipyrromethene ligand backbone. Partially alkylated dipyrromethenes containing 4–5 methyl substituents absorb in the region from 421 to 436 nm. For fully alkylated dipyrromethenes, the band maximum position shifts to the region from 437 to 446 nm for ligands with 4,4′-substituents in the sequence: methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl. The most significant spectral responses in the form of a red shift of 100 nm (in DMF) are observed when four methyl substituents in the 3,3′,5,5′-positions are replaced by phenyl groups. The replacement of the methine meso-spacer by a nitrogen atom leads to an additional red shift by another 70 nm. Particular attention is paid to the comparative analysis of the effect of structural factors on the coloristic and spectral responses of the complexation of dipyrromethene ligands with zinc(II) acetate and the stability of the resulting complexes [ZnL2], for which the lgKo values are varied from 6.4 to 10.9. The auxochromic action of Zn2+ cations shifts the band maxima of electronic absorption spectra to the long wavelength region by 20–76 nm relative to the spectra of the ligands. The highest complexation constant lgKo is 10.9 was obtained for the reaction of Zn(AcO)2 with hexamethylsubstituted dipyrromethene. Ligands with partially methylated pyrrole nuclei and extended alkyl and benzyl substituents form less stable complexes. The greatest effect of lowering the [ZnL2] stability is produced by the introduction of an electron-withdrawing aryl substituent into the meso-spacer of the dipyrromethene ligand (lgKo is 6.4).

Antina L.A., Ravcheeva E.A., Dogadaeva S.A., Kalyagin A.A., Ksenofontov A.A., Bocharov P.S., Lodochnikova O.A., Islamov D.R., Berezin M.B., Antina E.V.

The design of biocompatible photosensitizers with an optimal combination of intense fluorescence and generation of singlet oxygen is a complex and urgent task. The article presents the results of synthesizing, analyzing the structure, and examining the chromophoric, fluorescent, and generation characteristics of new dimeric bis(β-Br-BODIPY) (1), as well as the features of its encapsulation in ZIF-8 zeolite framework and solubilization by Pluronic® F127 micelles. The photophysical characteristics of brominated dimer 1 were analyzed in comparison with non-halogenated dimers bis(β-H-BODIPY) (2), bis(β-CH3-BODIPY) (3), as well as dibromo-substituted mononuclear analogue β,β-dibromo-BODIPY (4). Dye 1 exhibits efficient fluorescence (from 53 to 72%) and 1O2 generation (from 19 to 42%) in solutions of nonpolar and weakly polar solvents. Dimerization leads to a high sensitivity of the fluorescence and generation characteristics of the halogenated dimer 1 to the solvent. The advantage of dimer 1 is a significantly lower tendency to aggregate compared to monomer 4. The conditions for the encapsulation of dye 1 in ZIF-8 nanoparticles and Pluronic® F127 micelles were determined and their structural and spectral characteristics were analyzed.

Ovchenkova E.N., Bichan. N.G., Ksenofontov A.A., Shelaev I.V., Lomova T.N.

UV–vis, IR, MALDI-TOF, and femtosecond transient absorption spectroscopic techniques together with DFT and TDDFT computations have been employed to explore new manganese(III) porphyrins bearing [3,6-di-tert-butyl-carbazol-9-yl-benzoyloxy]- (MnP1) and [3,6-bis(3΄,6΄-di(tert-butyl)-9΄H-carbazol)-9H-carbazolbenzoyloxy]phenyl (MnP2) groups. MnP1 and MnP2 demonstrate the significant deviation of the macrocycle from planarity, which can be due to the high spin (S = 2) state of the manganese(III). By studying MnP1 and MnP2 excited states, the formation of the trip-quintet ones decaying in 13.7 ps and 17.3 ps, respectively, was established. The comparisons of MnP1 and MnP2 with the Co and Zn analogs have shown that both the number of generations and metal ion influence excited-state dynamics and electronic/structural properties.

Bumagina N.A., Ksenofontov A.A., Antina E.V., Berezin M.B.

This study presents a dipyrromethene-based sensitive and selective probe for Zn2+ ions detection in aqueous and water-organic media. The probe demonstrates absorbance-ratiometric and “off-on” fluorescent sensing for Zn2+ in a DMSO/H2O (9:1, v/v) mixture. The 2,2′,3,3′,4,4′-hexamethyl-2,2′-dipyrromethene (HL), similar to its analogs, exhibits weak fluorescence (with a quantum yield of less than 0.001). However, upon the presence of Zn2+ ions in the sensor HL solution, there is a remarkable increase (up to 200-fold) in fluorescence intensity due to the formation of a stable intramolecular chelate complex [ZnL2]. This complex formation induces a significant hyperchromic effect and a red shift (57 nm) in the characteristic absorption bands. The sensing mechanism of the probe towards Zn2+ ions was thoroughly investigated through absorbance and fluorescent titrations, molar ratio plots, 1H NMR, and DFT/TDDFT studies. The fluorescence response exhibited a strong linear relationship with Zn2+ concentration within the range of 0 to 5.7 × 10–6 mol/L. The detection limit (LOD) and limit of quantitation (LoQ) for Zn2+ were determined as 2 × 10–8 mol/L and 6.6 × 10–8 mol/L, respectively. Moreover, the probe demonstrated high selectivity for Zn2+ ions over other metal ions (Na+, Mg2+, Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Pd2+, Cd2+, Hg2+, Pb2+). Test systems in the form of test-strips and cotton-pads were developed based on the dipyrromethene sensor for rapid “naked-eye” detection of zinc ions in water. The sensor was successfully applied for detecting Zn2+ ions in real water samples.

Makarov D.M., Lukanov M.M., Rusanov A.I., Mamardashvili N.Z., Ksenofontov A.A.

The utilization of machine learning techniques for investigating chemical reactions is both sought after and challenging. While there are now many high-quality paid and free tools available for planning retrosynthesis, predicting the yield of different reaction types has received less attention, even though it is a crucial parameter for improving the synthesis process. This article aims to contribute to the application of machine learning in forecasting the yield of pyrrole and dipyrromethane condensation reactions with aldehydes. To achieve this, we trained a random forest model with an extended connectivity fingerprint on over 1200 such reactions, resulting in an MAE of 9.6 % and R2 of 0.63. To make it easier for users, we created the web application ChemPredictor (http://chem-predictor.isc-ras.ru/reaction/yield/) that allows users to input only the reaction components and temperature to predict the yield of these reactions.

Wang Z., Su P., Zhang M., Chai T., Wang S., Feng J., Lu C., Jin G.

Segovia-Pérez R., Ibarra-Rodríguez M., Muñoz-Flores B.M., Jiménez-Pérez V.M.

Chizhova N.V., Likhonina A.E., Tesakova M.V., Dmitrieva O.A., Parfenyuk V.I., Mamardashvili N.Z.

Muqadas, Shabbir A., Assiri M.A., Khan M., Shahzad S.A.

Ahmad N., Eid G., El-Toony M.M., Mahmood A.

Glavaš M., Vidoša L., Mušković M., Ratkaj I., Basarić N.

Chakradhar S.P., Krushna B.R., Sharma S.C., George A., Salwe K.J., Kar B., Banu A., Kumar K.G., Manjunatha K., Wu S.Y., Nagabhushana H.

Yang X., Li T., Chen X., Zhang H., Liu C., Tao C., Nie H.

Sharma G.D., Li P., Gu T., Fu Y., Liang X., Xu H., Singhal R.

Herein, a new nonfused fullerene‐free acceptor is synthesized based on the BODIPY‐coumarin triad, BDP‐2C, which exhibits a medium optical bandgap of about 1.51 eV, and HOMO and LUMO energy levels of about −5.50 and −4.00 eV, respectively. Employing BDP‐2C as a guest component in PM6:Y6, the resulting optimized ternary organic solar cells (OSCs) attained a power conversion efficiency (PCE) of about 15.09% with a low energy loss of 0.503 eV. The balanced charge transport and suppressed charge recombination, shorter charge extraction time, and prolonged charge carrier lifetime are the factors that enhance the PCE of ternary OSCs.

Khodadadi A.N., Cela E., Mosaffa H., Huang F., Marchionni D., Vaccaro L.

Wang M., Zhao W., Dong X.

Fluorescent dyes are widely applied in clinical diagnosis, detection, and treatment of diseases. Several image probes such as ICG, MB, and 5‐ALA have been approved by FDA. However, the limited tumor‐targeting capability of these dyes hinders their effectiveness in oncological imaging. Currently, various ligand‐based targeting probes have been developed to minimize nonspecific background emission. BRAF, especially BRAF V600E, is a common cancer gene and undergoes frequent mutation in melanoma. Small molecular BRAF kinase inhibitors have been approved for the treatment of melanoma patients carrying the BRAF V600E mutation, including Vemurafenib, Dabrafenib and so on. Boron dipyrromethene (BODIPY) as an important fluorescent class has been investigated extensively. Vemurafenib‐BODIPY has been reported to visualize BRAF V600E mutated cancer cells. Herein, the designed BODIPY‐based Vemurafenib derivatives targeting BRAF for cancer cell imaging are reported. The fluorescent probes are characterized and evaluated of photophysical properties, targeted binding and live cell imaging. Compound 1a exhibited promising fluorescence imaging ability. To improve fluorescence quantum yield, structural optimization is performed by incorporating meso N,N′‐dialkyl‐substituted amides to BODIPY core. Compound 1d shows excellent fluorescence properties and nice binding affinity. It allows visualization of BRAF V600E mutated cancer cells at low concentrations.

Pereira L.M., de Oliveira D.F., Tiburcio M.A., Ribeiro G.H., Moraes C.A., Neto F.O., Camargo A.J., De Boni L., Nascimento O.R., Homem M.G., Carlos R.M.

Fite S., Gross Z.

Yang R., Li L., Gao S., Weng Z., Li W., Wang Z., Li X., Yang Y., Jiang W.

Naeem S., Kadyrov T., Alsaiari N.S., Al-Buriahi M.S.

Eytcheson S.A., Tetko I.V.

The Tox24 challenge was designed to evaluate the progress that has been made in computational method development for the prediction of in vitro activity since the Tox21 challenge. In this challenge, participants were tasked with developing models to predict chemical binding to transthyretin (TTR), a serum binding protein, based on chemical structure. The analyzed dataset included chemicals that were screened in a competitive binding assay designed to measure the reduction in fluorescence due to displacement of 8-anilino-1-naphthalenesulfonic acid ammonium salt (ANSA) from TTR. The data were randomly split into a training set of 1012 compounds, a leaderboard set of 200, and a blind set of 300. This article provides an overview of the Tox24 Challenge and some of the models developed by the participating teams. Some of the approaches taken by winning teams included use of mixtures, enumerating tautomers, data cleaning. Many of the teams used consensus models. Overall, there has been significant progress in the development of machine learning tools since the Tox21 Challenge.

Makarov D.M., Kolker A.M.

Viscosity, the measure of a fluid's resistance to deformation, is a critical parameter in many industries. Being able to accurately predict viscosity is essential for the successful design and optimization of technological processes. In this research, regression models were created to predict the viscosity of deep eutectic solvents (DESs). Machine learning models were trained using a data set of 3440 data points for two component DESs. Different algorithms, such as Multiple Linear Regression, Random Forest, CatBoost, and Transformer CNF, were employed alongside a variety of structural representations like fingerprints, σ-profiles, and molecular descriptors. The effectiveness of the models was assessed for interpolation tasks within the training data and extrapolation outside of it. The results indicate that a rigorous splitting of the dataset into subsets is necessary to accurately evaluate the performance of the models. Two new choline chloride-based DESs were prepared and their viscosities were measured to evaluate the predictive capabilities of the models. The CatBoost algorithm with CDK molecular descriptors was chosen as the recommended model. The average absolute relative deviations (AARD) of this model exhibited fluctuations during 5-fold cross-validation, ranging from 10.8% when interpolating within the dataset to 88% when extrapolating to new mixture components. The open access model was presented in this study (http://chem-predictor.isc-ras.ru/ionic/des/).

Ji C., Gai L., Ni Z., Zhang Y., Jiang M., Qi F., Lu H.

Tetko I.V., van Deursen R., Godin G.

AbstractHyperparameter optimization is very frequently employed in machine learning. However, an optimization of a large space of parameters could result in overfitting of models. In recent studies on solubility prediction the authors collected seven thermodynamic and kinetic solubility datasets from different data sources. They used state-of-the-art graph-based methods and compared models developed for each dataset using different data cleaning protocols and hyperparameter optimization. In our study we showed that hyperparameter optimization did not always result in better models, possibly due to overfitting when using the same statistical measures. Similar results could be calculated using pre-set hyperparameters, reducing the computational effort by around 10,000 times. We also extended the previous analysis by adding a representation learning method based on Natural Language Processing of smiles called Transformer CNN. We show that across all analyzed sets using exactly the same protocol, Transformer CNN provided better results than graph-based methods for 26 out of 28 pairwise comparisons by using only a tiny fraction of time as compared to other methods. Last but not least we stressed the importance of comparing calculation results using exactly the same statistical measures.Scientific Contribution We showed that models with pre-optimized hyperparameters can suffer from overfitting and that using pre-set hyperparameters yields similar performances but four orders faster. Transformer CNN provided significantly higher accuracy compared to other investigated methods.

Shukla V.K., Sonavane S.S., Sekar N.

The modified BODIPY (pyrromethene) dyes with cyano (-CN), substituting usual fluorine (-F), at the 4-position may give enhanced photochemical stability and quantum yield of fluorescence (QYF) when compared to the corresponding fluoro derivative. We have investigated and discussed comparatively the structural parameters of the ground (S0) and excited (S1) state geometries of a few widely used BODIPY dyes, both 4-cyano and 4-fluoro pyrromethene (PM), through DFT and TD-DFT studies and established the reasons for improved QYF of the cyano derivatives. The electrophilicity index indicates the stability of the excited geometry of the cyanated BODIPY and the calculated transition dipole moments reveal a longer lifetime of the excited state (S1) for the cyano BODIPY. The higher singlet and triplet gap in cyanated BODIPY accounts for higher QYF due to restricted transition from singlet to triplet state. This suggests that a population inversion, crucial for laser action, is easier to build up for cyano derivative than for the commonly used fluoro analogue while other gain/loss parameters of the PM dye lasers remain similar. Hence, 4-cyano derivatives of the PM dyes may be useful for more efficient lasing applications. The non-linear optical properties of the PM dyes are also investigated.

Koli M., Gamre S., Ghosh R., Wadawale A.P., Ghosh A., Ghanty T.K., Mula S.

AbstractTo develop heavy‐atom‐free triplet photosensitizers (PSs) based photocatalysts, we designed and synthesized two BODIPY‐helicene dyes by fusing the BODIPY core and modified [5]helicene structures. These BODIPY‐helicenes structures are twisted and their twisting angles are increased by the developed synthetic method. The BODIPY‐helicenes have broad absorption bands over UV‐visible region with high triplet conversions and long triplet lifetimes as compared to planar BODIPY dye, PM567. Consequently, these dyes are also highly efficient in generating 1O2 by transferring their triplet energy to 3O2. All these are confirmed by dye‐sensitised photooxidation reaction, nanosecond transient absorption spectroscopy study, phosphorescence measurement and DFT calculations. Finally, photocatalytic activity of the highest 1O2 generating BODIPY‐helicene (4 b) was checked. 4 b is highly efficient in photocatalytic oxidative coupling of differently substituted amines through aerobatic oxidation using 1O2 generated by its photosensitization. It is also highly efficient photocatalyst for aerobatic oxidation of sulfides to sulfoxides. Importantly, the photocatalyst could be quantitatively recovered and reused for several cycles. All these results confirmed the potential use of the BODIPY‐helicenes as PSs for photocatalytic organic reactions and the design strategy will be useful for the future development of heavy‐atom‐free photocatalyst.

Mack J., Kubheka G., May A., Ngoy B.P., Nyokong T.

Since 2017, the Institute for Nanotechnology Innovation at Rhodes University has studied the optical limiting properties of boron dipyrromethene (BODIPY) dyes with respect to high-intensity nanosecond timescale laser pulses. Concerns...

Eytcheson S.A., Zosel A.D., Olker J.H., Hornung M.W., Degitz S.J.

Du C., Chen J., Zhang G., Zhang H., Cheng Y.

Ksenofontova K.V., Shagurin A.Y., Molchanov E.E., Ksenofontov A.A., Sbytov D.A., Kalyamanova Y.E., Danilova E.A., Marfin Y.S.

AbstractTwo π‐extended derivatives of boron‐dipyrromethene (BODIPY) – unsymmetrical benzo[b]‐fused BODIPY 1 and symmetrical naptho[b]‐fused BODIPY 2 – were synthesized. Spectroscopic and photophysical properties of the synthesized fluorescent dyes were investigated in various organic media. Both BODIPY 1 and BODIPY 2 distinguished by bathochromically shifted absorption and emission bands compared to their non‐fused derivatives, while possessing green (526–543 nm) and red (664–708 nm) absorbance and fluorescence, respectively. Spectral characteristics of the investigated fluorescent dyes were found to be weakly depended on solvent polarizability in case of BODIPY 1 and greatly influenced by both solvent polarizability and dipolarity in case of BODIPY 2. Quantum chemical calculations were used to clarify the relationships between geometry/electronic structure and spectral properties/solvatochromic behavior of BODIPY 1 and BODIPY 2.

Saczuk K., Dudek M., Matczyszyn K., Deiana M.

Molecular disassembly is pioneering a new route to refined diagnostic and therapeutic solutions. This approach breaks down self-assembled molecules, offering enhanced precision and efficiency in various bio-oriented applications.

Chen Z., Yue L., Guo Y., Huang H., Lin W.

Diabetes mellitus is a disorder that affects lipid metabolism. Abnormalities in the lipid droplets (LDs) can lead to disturbances in lipid metabolism, which is a significant feature of diabetic patients. Nevertheless, the correlation between diabetes and the polarity of LDs has received little attention in the scientific literature. In order to detect LDs polarity changes in diabetes illness models, we created a new fluorescence probe LD-DCM. This probe has a stable structure, high selectivity, and minimal cytotoxicity. The probe formed a typical D-π-A molecular configuration with triphenylamine (TPA) and dicyanomethylene-4H-pyran (DCM) as electron donor and acceptor parts. The LD-DCM molecule has an immense solvatochromic effect (λ

Saiyasombat W., Muangsopa P., Khrootkaew T., Chansaenpak K., Pinyou P., Sapermsap N., Sangtawesin S., Kamkaew A.

AbstractBOIMPY (bis‐ (borondifluoride)‐8‐imidazodipyrromethene) photosensitizers were developed for imaging‐guided photodynamic therapy (PDT). The introduction of heavy atoms (Br and I) to the β‐positions of BOIMPY combined with the twisted structure of the molecule was the strategy to enhance the intersystem crossing process of the BOIMPYs and reduce intermolecular π–π interactions of BOIMPY core. To clarify the electronic features of BOIMPY derivatives, their optical properties were studied using UV‐vis absorption, fluorescence spectroscopy, electrochemistry, and density functional theory (DFT) computing. The halogenated BOIMPYs exhibited a high absorption coefficient with high singlet oxygen generation ability (ΦΔ=0.46 and 0.94 for brominated and iodinated BOIMPY, respectively). More significantly, an in vitro investigation showed that all derivatives displayed fluorescence in cancer cells and that the halogenated BOIMPYs increased the effectiveness of tumor inhibition upon exposure to 660 nm red LED light radiation. The half‐maximal inhibitory concentrations for the iodinated and brominated BOIMPYs were 2.14 μM and 14.78 μM, respectively. Consequently, iodinated BOIMPY has been shown to represent a new class of photosensitizers with potential use in imaging‐guided photodynamic therapy.

Guo L., Guo X., Zuo H., Li H., Lv F., Wu Q., Jiao L., Hao E.

AbstractHypoxic tumor microenvironments pose significant challenges to the clinical translation of cancer photodynamic therapy (PDT). While heavy atom‐free Type‐I boron dipyrromethenes (BODIPYs) photosensitizers can alleviate this challenge by reducing oxygen dependency, but they remain scarce. Herein, heavy‐atom‐free α,meso‐linked bisBODIPYs were designed and synthesized. These bisBODIPYs exhibit remarkable red‐shifted emission (λemmax ~670 nm), large Stokes shifts (~4480 cm−1) and they are capable of producing both superoxide anion (O2⋅−) and singlet oxygen (1O2) in solution and cells. Additionally, they offer a wide PDT treatment window, ranging from 0.26 to 83.5 μM. Furthermore, these bisBODIPYs also demonstrate superior two‐photon fluorescence, promising for surgical navigation and integrating diagnosis with treatment.

Aldossary A., Campos‐Gonzalez‐Angulo J.A., Pablo‐García S., Leong S.X., Rajaonson E.M., Thiede L., Tom G., Wang A., Avagliano D., Aspuru‐Guzik A.

AbstractComputational chemistry is an indispensable tool for understanding molecules and predicting chemical properties. However, traditional computational methods face significant challenges due to the difficulty of solving the Schrödinger equations and the increasing computational cost with the size of the molecular system. In response, there has been a surge of interest in leveraging artificial intelligence (AI) and machine learning (ML) techniques to in silico experiments. Integrating AI and ML into computational chemistry increases the scalability and speed of the exploration of chemical space. However, challenges remain, particularly regarding the reproducibility and transferability of ML models. This review highlights the evolution of ML in learning from, complementing, or replacing traditional computational chemistry for energy and property predictions. Starting from models trained entirely on numerical data, a journey set forth toward the ideal model incorporating or learning the physical laws of quantum mechanics. This paper also reviews existing computational methods and ML models and their intertwining, outlines a roadmap for future research, and identifies areas for improvement and innovation. Ultimately, the goal is to develop AI architectures capable of predicting accurate and transferable solutions to the Schrödinger equation, thereby revolutionizing in silico experiments within chemistry and materials science.