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For the first time, the potentiality of the sp 2-hybridized group IV-VII radical (R•)-containing molecules to participate in R•-hole interactions was comparatively assessed using •SiF 3, •POF 2 , •SO 2 F, and •ClO 3 models in the trigonal pyramidal geometry. In that spirit, a plethora of quantum mechanical calculations was performed at the MP2/aug-cc-pVTZ level of theory. According to the results, all the investigated R•-containing molecules exhibited potent versatility to engage in R•-hole ... Lewis base interactions with significant negative binding energies for the NCH-based complexes. The strength of R•-hole interactions was perceived to obey the •ClO 3 ... > •SO 2 F ... > •POF 2 ... > •SiF 3 ... Lewis base order, outlining an inverse correlation between the binding energy and the atomic size of the R•-hole donor. Benchmarking of the binding energy at the CCSD/CBS(T) computational level was executed for all the explored interactions and addressed an obvious similarity between the MP2 and CCSD energetic findings. QTAIM analysis critically unveiled the closed-shell nature of the explored R•-hole interactions. SAPT-EDA proclaimed the reciprocal contributions of electrostatic and dispersion forces to the total binding energy. These observations demonstrate in better detail the nature of R•-hole interactions, leading to a convincing amelioration for versatile fields relevant to materials science and drug design. [Display omitted] • The ability of group IV-VII elements to participate in R.•-hole interactions was proved. • R.•-hole interaction strength was inversely correlated with the atomic size of R•-hole donor. • QTAIM analysis unveiled the closed-shell nature of the explored R.•-hole interactions. • SAPT-EDA proclaimed the contributions of electrostatic and dispersion forces. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) is a new pandemic characterized by quick spreading and illness of the respiratory system. To date, there is no specific therapy for Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). Flavonoids, especially rutin, have attracted considerable interest as a prospective SARS-CoV-2 main protease (Mpro) inhibitor. In this study, a database containing 2017 flavone analogs was prepared and screened against SARS-CoV-2 Mpro using the molecular docking technique. According to the results, 371 flavone analogs exhibited good potency towards Mpro with docking scores less than −9.0 kcal/mol. Molecular dynamics (MD) simulations, followed by molecular mechanics-generalized Born surface area (MM/GBSA) binding energy calculations, were performed for the top potent analogs in complex with Mpro. Compared to rutin, PubChem-129-716-607 and PubChem-885-071-27 showed better binding affinities against SARS-CoV-2 Mpro over 150 ns MD course with Δ G binding values of −69.0 and −68.1 kcal/mol, respectively. Structural and energetic analyses demonstrated high stability of the identified analogs inside the SARS-CoV-2 Mpro active site over 150 ns MD simulations. The oral bioavailabilities of probable SARS-CoV-2 Mpro inhibitors were underpinned using drug-likeness parameters. A comparison of the binding affinities demonstrated that the MM/GBSA binding energies of the identified flavone analogs were approximately three and two times less than those of lopinavir and baicalein, respectively. In conclusion, PubChem-129-716-607 and PubChem-885-071-27 are promising anti-COVID-19 drug candidates that warrant further clinical investigations. [Display omitted] • A database containing 2017 flavone analogs was prepared and screened against SARS-CoV-2 Mpro using in silico techniques. • PubChem-129-716-607 and PubChem-885-071-27 demonstrated higher binding affinities against Mpro than rutin and baicalein. • PubChem-129-716-607 and PubChem-885-071-27 exhibited high stability inside the Mpro active site over 150 ns MD simulations. • PubChem-129-716-607 and PubChem-885-071-27 manifested promising drug-likeness properties. [ABSTRACT FROM AUTHOR]

Minimizing the energy loss and improving the open circuit voltage of organic solar cells is still a primary concern for scientists working in this field. With the aim to enhance the photovoltaic performance of organic solar cells by minimizing energy loss and improving open circuit voltage, seven new acceptor molecules (LC1-LC7) are presented in this work. These molecules are designed by modifying the terminal acceptors of pre-existed "LC81" molecule based on an indacinodithiophene (IDT) fused core. The end-group modification approach is very fruitful in ameliorating the efficacy and optoelectric behavior of OSCs. The newly developed molecules presented remarkable improvements in performance-related parameters and optoelectronic properties. Among all designed molecules, LC7 exhibited the highest absorption maxima (λ max = 869 nm) with the lowest band-gap (1.79 eV), lowest excitation energy (E x = 1.42 eV), lowest binding energy, and highest excited state lifetime (0.41 ns). The newly designed molecules LC2, LC3, and LC4 exhibited remarkably improved Voc that was 1.84 eV, 1.82 eV, and 1.79 eV accordingly, compared to the LC81 molecule with V oc of 1.74 eV LC2 molecule showed significant improvement in fill factor compared to the previously presented LC81 molecule. LC2, LC6, and LC7 showed a remarkable reduction in energy loss by showing E loss values of 0.26 eV, 0.18 eV, and 0.25 eV than LC81 molecule (0.37 eV). These findings validate the supremacy of these developed molecules (especially LC2) as potential components of future OSCs. [Display omitted] [ABSTRACT FROM AUTHOR]

To intensify the photovoltaic properties of organic solar cells, density functional theory (DFT) based computational techniques were implemented on six non-fullerene A-D-A type small molecules (N1–N6) modified from reference molecule (R) which consists of phenazine fused with 1,4- Dimethyl-4H-3,7-dithia-4-aza- cyclopenta [α] pentalene on both sides with one of its phenyl rings acting as the central donor unit, further attached with 2-(5,6-Difluoro-2-methylene-3-oxo-indan-1-ylidene)-malononitrile acceptor groups at terminal sites. All proposed compounds have a phenazine base modified with a variety of substituents at the terminals. Transition density matrix, density of states, frontier molecular orbitals, intramolecular charge transfer abilities and optoelectronic properties of these compounds were investigated using B3LYP/6-31G (d, p) and B3LYP/6-31G++ (d,p) level of theory. All six designed compounds exhibited a bathochromic sift in their λ max as compared to the R molecule. All designed molecules also have reduced band gap and smaller excitation energy than R. Among all, N6 exhibited highest λ max and lowest bandgap as compared to reference molecule indicating its promising photovoltaic properties. Decreased hole and electron reorganization energy in several of the suggested compounds is indicative of greater charge mobility in them. PTB7-Th donor was employed to calculate open circuit voltage of all investigated molecules. N1–N5 molecules had improved optoelectronic properties, significant probable power conversion efficiency as evident from their absorption aspects, high values of V oc , and fill factor, compared to R molecule. Designed A-D-A type NF based molecules make OSCs ideal for use in wearable devices, building-integrated photovoltaics and smart fabrics. [ABSTRACT FROM AUTHOR]

Despite the substantial advancements in organic solar cells (OSCs), the best devices still have quite low efficiencies due to less focus on donor molecules. With the intention to present efficient donor materials, seven small donor molecules (T1 - T7) were devised from DRTB-T molecule by using end-capped modeling. Newly designed molecules exhibited remarkable improved optoelectronic properties such as less band gap (from 2.00 to 2.23 eV) than DRTB-T having band gap of 2.57 eV. Similarly, a significant improvement in λ max values was noticed in designed molecules in gaseous medium (666 nm–738 nm) and solvent medium (691 nm–776 nm) than DRTB-T having λ max values at 568 nm and 588 nm in gas and solvent phase respectively. Among all molecules, T1 and T3 exhibited significant improvement in optoelectronic properties such as narrow band gap, lower excitation energy, higher λ max values and lower electron reorganization energy as compared to pre-existed DRTB-T molecule. The better functional ability of T1 - T7 is also suggested by an improvement in open circuit voltage (Voc) of designed structures (1.62 eV–1.77 eV) as compared to R (1.49 eV) when PC 61 BM is used as an acceptor. So, all our newly derived donors can be employed in the active layer of organic solar cells to manufacture efficient OSCs. [ABSTRACT FROM AUTHOR]