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Sunscreens, a primary defense against ultraviolet (UV) radiation, use UV filters to mitigate the harmful effects of UVA and UVB radiation, including DNA damage, skin aging, and cancer. However, organic UV filters like benzophenones, oxybenzone, sulisobenzone, and PABA are persistent pollutants, posing environmental risks due to their incomplete removal by conventional wastewater treatment. This study investigates the encapsulation of hazardous UV filters inside a stable belt[14]pyridine nanobelt to facilitate their removal through host-guest interactions. The higher values of interaction energies (E int ) of the designed host-guest complexes ranging from − 13.70 to −26.11 kcal/mol, ensure the stability of the complexes. Frontier molecular orbital (FMO) analysis reveal the significant role of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the host nanobelt towards the HOMO and LUMO of complexes, which is confirmed via density of states (DOS) analysis. Natural bond orbital (NBO) analysis determines the direction of charge transfer, i.e., from the host towards guest species in all complexes. The highest magnitude of NBO charge is observed for sulisobenzone@belt complex, i.e., 0.022|e|. Electron density difference (EDD) analysis visually illustrate the accumulation of charge density over the guest in all the complexes, i.e., a validation of the direction of charge transfer predicted via NBO analysis. The results of non-covalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses reveal that the host-guest complexes are stabilized via van der Waals interactions, and a greater number of bond critical points (BCPs) are found for sulisobenzone@belt i.e., 15. Moreover, the recovery time decreases with increasing temperature and is highest for the complex with greater E int i.e., 1.4 10 7 s (at 298 K) for oxybenzone@belt complex. Overall, the study aims to design stable host-guest complexes for effective encapsulation of harmful UV filters, in order to reduce their harmful effects.

Here, the encapsulation behavior of Cucurbit[7]uril (CB[7]) is studied for six organic UV filters, i.e., benzophenone, homosalate, oxybenzone, dioxybenzone, sulisobenzone, and para aminobenzoic acid (PABA) using density functional theory (DFT). The thermodynamic stability of the designed systems is ensured by the values of interaction energies ranging from − 11.78 to -20.42 kcal/mol, with the highest value observed for dioxybenzone@CB[7]. Non-covalent interaction (NCI) analysis highlights the prevalence of van der Waals interactions in host-guest complexes, supported by quantum theory of atoms in molecule (QTAIM) analysis. The values of interaction energies of individual bonds in QTAIM analysis fall below 3 kcal/mol confirming the van der Waals interactions between the host and guest species. Frontier molecular orbital (FMO) and density of states (DOS) analyses indicate decreased energy gaps in the complexes compared to bare species, while natural bond orbital (NBO) analysis reveals charge transfer from host to guests with the highest observed for oxybenzone@CB[7] (-0.019|e|). Recovery time and desorption energy analysis highlight dioxybenzone@CB[7] as the most strongly adsorbed complex, while benzophenone@CB[7] being the least. The analysis also suggest a decrease in recovery time with increasing temperature (i.e., least for benzophenone@belt complex, i.e., 2.7 10 −6  s at 400 K). These findings illustrate CB[7] as an efficient host for encapsulating organic UV filters, offering a promising approach for reducing their negative ecological consequences.

Carbon-based polynuclear clusters are designed and investigated for geometric, electronic, and nonlinear optical (NLO) properties at the CAM-B3LYP/6-311++G(d,p) level of theory. Significant binding energies per atom (ranging from −162.4 to −160.0 kcal mol−1) indicate excellent thermodynamic stabilities of these polynuclear clusters. The frontier molecular orbital (FMOs) analysis indicates excess electron nature of the clusters with low ionization potential, suggesting that they are alkali-like. The decreased energy gaps (EH-L) with increased alkali metals size revael the improved electrical conductivity (σ). The total density of state (TDOS) study reveals the alkali metals’ size-dependent electronic and conductive properties. The significant first and second hyperpolarizabilities are observed up to 5.78 × 103 and 5.55 × 106 au, respectively. The βo response shows dependence on the size of alkali metals. Furthermore, the absorption study shows transparency of these clusters in the deep-UV, and absorptions are observed at longer wavelengths (redshifted). The optical gaps from TD-DFT are considerably smaller than those of HOMO-LUMO gaps. The significant scattering hyperpolarizability (βHRS) value (1.62 × 104) is calculated for the C3 cluster, where octupolar contribution to βHRS is 92%. The dynamic first hyperpolarizability β(ω) is more pronounced for the EOPE effect at 532 nm, whereas SHG has notable values for second hyperpolarizability γ(ω).

Numerous issues with pharmacokinetics and water solubility of current anticancer drugs have hindered the development of chemotherapy, resulting in significant side effects and patient resistance to multiple therapies. Nanomedicine revolutionized cancer treatment by introducing nanocarriers to enhance drug delivery. This study investigates the use of benzimidazolone capsules as nanocarrier for drug delivery of flutamide (FLT) and gemcitabine (GB) (FLT@Cap and GB@Cap). Numerous structural and electrical parameters demonstrate that both drugs interact well with nanocapsules and are easily transported to the targeted site. Using complexation energy analysis, quantum theory of atoms in molecules (QTAIM), non-covalent interactions (NCI), natural bond orbital (NBO), frontier molecular orbital (FMO), and density of states (DOS) analyses, the drug delivery of flutamide (FLT) and gemcitabine (GB) via benzimidazolone capsule is described. FLT@Cap and GB@Cap exhibit strong drug-capsule interaction, with adsorption energies of -42.18 and − 51.59 kcal/mol, respectively. QTAIM and NCI analysis validate the non-covalent interactions between FLT, GB, and capsule. To comprehend the shifting of electron density from drug to surface, NBO analysis is utilized. After complexation, (E H−L ) which describes the HOMO-LUMO energy gap is reduced, and the perturbations in the electronic parameters are estimated using FMO analysis. The results indicate a high degree of selectivity for FLT and GB on the surface of the benzimidazolone capsule.

The toxicity of transition metals, including copper(II), manganese(II), iron(II), zinc(II), hexavalent chromium, and cobalt(II), at elevated concentrations presents a significant threat to living organisms. Thus, the development of efficient sensors capable of detecting these metals is of utmost importance. This study explores the utilization of two-dimensional nitrogenated holey graphene (C2N) nanosheet as a sensor for toxic transition metals. The C2N nanosheet’s periodic shape and standard pore size render it well suited for adsorbing transition metals. The interaction energies between transition metals and C2N nanosheets were calculated in both gas and solvent phases and were found to primarily result from physisorption, except for manganese and iron which exhibited chemisorption. To assess the interactions, we employed NCI, SAPT0, and QTAIM analyses, as well as FMO and NBO analysis, to examine the electronic properties of the TM@C2N system. Our results indicated that the adsorption of copper and chromium significantly reduced the HOMO–LUMO energy gap of C2N and significantly increased its electrical conductivity, confirming the high sensitivity of C2N towards copper and chromium. The sensitivity test further confirmed the superior sensitivity and selectivity of C2N towards copper. These findings offer valuable insight into the design and development of sensors for the detection of toxic transition metals.

The corrosion inhibition effect of the three extracts from Harmal roots (HRE), leaves (HLE), and flowers (HFE) were studied for carbon steel corrosion inhibition in 0.25 M H2SO4 solution. The electrochemical impedance study indicated that the three types of extracts decreased corrosion effectively through a charge transfer mechanism. Harmal roots and leaf extracts showed inhibition values of 94.1% and 94.2%, while it was 88.7% for Harmal flower extract at the inhibitor concentration of 82.6 ppm. Potentiodynamic polarization data revealed that Harmal extracts acted through predominant cathodic type inhibition. Both the corrosion current density and corrosion rate decreased significantly in the presence of Harmal extracts compared to blank solution. The corrosion rate (mpy) value was 63.3, 86.1, and 180.7 for HRE, HLE, and HFE, respectively. The adsorption-free energy change ΔGads (kJ·mol−1) values calculated from the Langmuir adsorption isotherm plots were for HRE (−35.08), HLE (−33.17), and HFE (−33.12). Thus, corrosion inhibition occurred due to the adsorption of Harmal extract on the carbon steel surface via the chemisorption mechanism. Moreover, a computational investigation using B3LYP/6-311G++(d,p) basis set in both gaseous and aqueous phases was performed for the major alkaloids (1–8) present in the Harmal extract.

The use of nanomaterials as drug delivery systems is an area of interest for various anticancer drugs, aiming to minimize their side effects while ensuring they reach the target site effectively. In the current study, Benzotriazole capsule as drug delivery system for cyclophosphamide (CP) and gemcitabine (GB) drugs adsorption is explored. Various electronic and structural parameters shows that both drugs have good interaction with nanocapsule and can be carried to the target site easily. The calculated binding energies of drug@Capsule complexes are in the range of −43.34 and − 56.64 kcal/mol, which shows stronger interaction of drug molecules with nanocapsule. The noncovalent interactions between CP, GB and capsule are confirmed through QTAIM and NCI analyses. NBO analysis is used to understand the shifting of electron density, which shifts from drug to surface. FMO analysis is performed to estimate the perturbations in the electronic parameters upon complexation, which reveals reduction in the E H−L gap. Moreover, pH effect and dipole moment analysis are performed to get insight into the drug release mechanism. Dipole moment values indicate that nanocapsule can effectively release CP drug on a target site. The findings suggest that benzotriazole capsule surface is highly selective toward CP and GB.

In this work it is demonstrated that enantiomerically enriched N-alkyl 2-oxazolinylazetidines undergo exclusive α-lithiation, and that the resulting lithiated intermediate is chemically stable but configurationally labile under the given experimental conditions that afford enantioenriched N-alkyl-2,2-disubstituted azetidines. Although this study reveals the configurational instability of the diastereomeric lithiated azetidines, it points out an interesting stereoconvergence of such lithiated intermediates towards the thermodynamically stable species, making the overall process highly stereoselective (er > 95:5, dr > 85:15) after trapping with electrophiles. This peculiar behavior has been rationalized by considering the dynamics at the azetidine nitrogen atom, the inversion at the C-Li center supported by in situ FT-IR experiments, and DFT calculations that suggested the presence of η3-coordinated species for diastereomeric lithiated azetidines. The described situation contrasted with the demonstrated stability of the smaller lithiated aziridine analogue. The capability of oxazolinylazetidines to undergo different reaction patterns with organolithium bases supports the model termed “dynamic control of reactivity” of relevance in organolithium chemistry. It has been demonstrated that only 2,2-substituted oxazolinylazetidines with suitable stereochemical requirements could undergo C=N addition of organolithiums in non-coordinating solvents, leading to useful precursors of chiral (er > 95:5) ketoazetidines.

V-series nerve agents are very lethal to health and cause the inactivation of acetylcholinesterase which leads to neuromuscular paralysis and, finally, death. Therefore, rapid detection and elimination of V-series nerve agents are very important. Herein, we have carried out a theoretical investigation of carbon nitride quantum dots (C2N) as an electrochemical sensor for the detection of V-series nerve agents, including VX, VS, VE, VG, and VM. Adsorption of V-series nerve agents on C2N quantum dots is explored at M05-2X/6-31++G(d,p) level of theory. The level of theory chosen is quite adequate in systems describing non-bonding interactions. The adsorption behavior of nerve agents is characterized by interaction energy, non-covalent interaction (NCI), Bader’s quantum theory of atoms in molecules (QTAIM), frontier molecular orbital (FMO), electron density difference (EDD), and charge transfer analysis. The computed adsorption energies of the studied complexes are in the range of −12.93 to −17.81 kcal/mol, which indicates the nerve agents are physiosorbed onto C2N surface through non-covalent interactions. The non-covalent interactions between V-series and C2N are confirmed through NCI and QTAIM analysis. EDD analysis is carried out to understand electron density shifting, which is further validated by natural bond orbital (NBO) analysis. FMO analysis is used to estimate the changes in energy gap of C2N on complexation through HOMO-LUMO energies. These findings suggest that C2N surface is highly selective toward VX, and it might be a promising candidate for the detection of V-series nerve agents.

Currently, hydrogen is recognized as the best alternative for fossil fuels because of its sustainable nature and environmentally friendly processing. In this study, hydrogen dissociation reaction is studied theoretically on the transition metal doped carbon nitride (C2N) surface through single atom catalysis. Each TMs@C2N complex is evaluated to obtain the most stable spin state for catalytic reaction. In addition, electronic properties (natural bond orbital NBO & frontier molecular orbital FMO) of the most stable spin state complex are further explored. During dissociation, hydrogen is primarily adsorbed on metal doped C2N surface and then dissociated heterolytically between metal and nitrogen atom of C2N surface. Results revealed that theFe@C2N surface is the most suitable catalyst for H2 dissociation reaction with activation barrier of 0.36 eV compared with Ni@C2N (0.40 eV) and Co@C2N (0.45 eV) complexes. The activation barrier for H2 dissociation reaction is quite low in case of Fe@C2N surface, which is comparatively better than already reported noble metal catalysts.