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The detection of toxic molecules has gained imperial attention to protect living organisms and their environment. The broadly explored sensor behaviour of triazine-based C3N4 reveals their ultra-high sensitivity towards numerous toxic molecules e.g., chemical welfare agents. However, another potential analogue of C3N4 composed of heptazine exhibits remarkable electrical and optical properties but has not been much explored in sensor technology, especially for toxic pollutants. Keeping this in mind, the sensing performance of heptazine-based g-C3N4 is explored for the detection of toxic amides by using First Principles calculations. In this context, acryloyl amide (C2H3CONH2), acryloyl chloride (C2H3COCl), fluoroacetic acid (C2H3FCOOH), flouroaceta amide (C2H2FONH2), flouroacetyl chloride (C2H2FOCl) are selected as toxic pollutants; herein, for the ease of understanding, these molecules are represented as AAM, ACl, FAAc, FAA, & FACl, respectively. The electrochemical sensitivity of g-C3N4 is determined via geometric, energetic, and electronic properties analysis, whereas the photochemical sensitivity is explored by UV–Vis absorption analysis based on TD-DFT calculations. The interaction energies of studied molecules on C3N4 range between − 9.09 and - 23.39 kcal/mol depending upon the type of interactions e.g., hydrogen bonding or dispersion, which are explained on the basis of Symmetry Adopted Perturbation Theory, Non-Covalent Interaction Index, and Quantum Theory of Atoms in Molecules analyses. The density of State analysis, Frontier Molecular Orbitals and NBO charge transfer characterized that the electronic behaviour of g-C3N4 can be an effective sensor material with a semiconducting nature and significant charge transfer. Lastly, UV–Vis absorption analysis confirms the photosensitivity of g-C3N4 upon interaction with toxic molecules. [ABSTRACT FROM AUTHOR]

In this study, for the first time, boron oxide nanoflake is analyzed as drug carrier for favipiravir using computational studies. The thermodynamic stability of the boron oxide and favipiravir justifies the strong interaction between both species. Four orientations are investigated for the interaction between the favipiravir and the B3O3 nanoflake. The Eint of the most stable orientation is −26.98 kcal/mol, whereas the counterpoise-corrected energy is −22.59 kcal/mol. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses are performed to obtain insights about the behavior and the types of interactions that occur between B3O3 nanoflake and favipiravir. The results indicate the presence of hydrogen bonding between the hydrogen in the favipiravir and the oxygen in the B3O3 nanoflake in the most stable complex (FAV@B3O3-C1). The electronic properties are investigated through frontier molecular orbital analysis, dipole moments and chemical reactivity descriptors. These parameters showed the significant activity of B3O3 for favipiravir. NBO charge analysis transfer illustrated the charge transfer between the two species, and UV-VIS analysis confirmed the electronic excitation. Our work suggested a suitable drug carrier system for the antiviral drug favipiravir, which can be considered by the experimentalist for better drug delivery systems. [ABSTRACT FROM AUTHOR]

In this study, we explored the reversible hydrogen storage capacity of Ni functionalized C10 carbyne complex through density functional theory (DFT) and molecular dynamic (MD) calculations. ωB97X-D3/def2-TZVP and DLPNO-CCSD(T)/def2-TZVPP methods are used for the estimation of adsorption energies. NiC10 complex is observed to be more sensitive toward hydrogen adsorption compared to isolated C10 carbyne. The nH2-NiC10 complexes are stable when n ≤ 5, and adsorption energies are in the range of − 0.89 to − 0.22 eV/H2 molecule while the hydrogen storage capacity is about 1.11 to 5.33 wt% for hydrogen molecule. For desorption of H2, molecular dynamic calculations are performed at ωB97X-D3 with def2-TZVP O using RCA ABMD package in which the complexes showed stability to desorption up to 2000 steps. This study illustrates the potential of nickel-doped carbyne C10 complex for the storage of hydrogen and applications in fuel cells. [ABSTRACT FROM AUTHOR]

N-(2-bromo-4-nitrophenyl)-3-methoxy-4-oxo-3,4-dihydro-2H-benzo[e][1,2]thiazine-3-carboxamide-1,1-dioxide was synthesized in three step process with 86 % overall yield. The final structure of compound was evaluated by using spectroscoanalytical methods (1H-NMR and FT-IR). Suitable crystals were obtained by slow evaporation method, and the final structure was confirmed unequivocally by performing single crystal X-ray diffraction (XRD) studies. Geometric parameters were calculated at B3LYP/6-31G (d, p) method with the help of Gaussian 09 software to validate spectrosopic and single crystal X-ray results. The computed data corroborated nicely with the experimental results (spectroscopic and X-ray). Frontier molecular orbitals (FMOs) and reactivity indices revealed the reactivity of benzothiazine derivative. Molecular electrostatic potential (MEP) was measured to understand the electro or nucleophilic nature of compound. Mulliken and natural population charge analysis (NBO) was carried out to prove inter and intramolecular hydrogen bonding. [ABSTRACT FROM AUTHOR]

Grignard reactions are of importance in organic chemistry for the synthesis β‐keto esters and diethyl malonate, alcohols, aldehydes or ketones, monocarboxylic acids, and other organometallic compounds. Generally, the heterolytic dissociation of C─Mg bond in Grignard reagent is the key step in these reactions. Recently, homolytic cleavage of the C─Mg bond in Grignard reagents has been reported in the preparation of stable radicals. These reactive species react with other compounds, which result in the formation of hydrocarbons and their derivatives. Therefore, the study of homolytic cleavage of C─Mg bonds is quite vital to better understand the kinetics and thermodynamics of these reactions. In the current study, a benchmark approach is adopted to find a cost‐effective and accurate density functional (DF) for bond dissociation energies measurement of the C─Mg bond of Grignard reagents. Twenty‐nine DFs from 13 density functional theory (DFT) classes with three types of basis sets (Pople' 6‐31G(d) and 6‐311G(d), Dunning's aug‐cc‐pVDZ, and Karlsruhe' def2‐SVP basis sets) are implemented for the measurement of dissociation energies of the C─Mg bond. Theoretical dissociation energy values are compared with experimental reported values of the C─Mg bond of selected Grignard reagents. TPSSTPSS of the meta‐GGA class with 6‐31G (d) basis set gave accurate results, and its Pearson's correlation is 0.95. SD, root mean square deviation, and mean unsigned error of this method are 2.36 kcal mol−1, 2.33 kcal mol−1, and −0.46 kcal mol−1, respectively. TPSSTPSS of the meta‐GGA class is a one‐electron, self‐interaction, error‐free Tao‐Perdew‐Staroverov‐Scuseria functional that performed better with the 6‐31G(d) basis set. [ABSTRACT FROM AUTHOR]

Ab initio calculations were performed to determine the sensing behavior of g-C 3 N 4 and Li metal-doped g-C 3 N 4 (Li/g-C 3 N 4 ) quantum dots toward toxic compounds acetamide (AA), benzamide (BA), and their thio-analogues, namely, thioacetamide (TAA) and thiobenzamide (TAA). For optimization and interaction energies, the ωB97XD/6-31G(d,p) level of theory was used. Interaction energies ( E int ) illustrate the high thermodynamic stabilities of the designed complexes due to the presence of the noncovalent interactions. The presence of electrostatic forces in some complexes is also observed. The observed trend of E int in g-C 3 N 4 complexes was BA > TAA > AA > TBA, while in Li/g-C 3 N 4 , the trend was BA > AA > TBA > TAA. The electronic properties were studied by frontier molecular orbital (FMO) and natural bond orbital analyses. According to FMO, lithium metal doping greatly enhanced the conductivity of the complexes by generating new HOMOs near the Fermi level. A significant amount of charge transfer was also observed in complexes, reflecting the increase in charge conductivity. NCI and QTAIM analyses evidenced the presence of significant noncovalent dispersion and electrostatic forces in Li/g-C 3 N 4 and respective complexes. Charge decomposition analysis gave an idea of the transfer of charge density between quantum dots and analytes. Finally, TD-DFT explained the optical behavior of the reported complexes. The findings of this study suggested that both bare g-C 3 N 4 and Li/g-C 3 N 4 can effectively be used as atmospheric sensors having excellent adsorbing properties toward toxic analytes., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

In the pursuit of sustainable clean energy sources, the hydrogen evolution reaction (HER) has attained significant interest from the scientific community. Single-atom catalysts (SACs) are among the most promising candidates for future electrocatalysis because they possess high thermal stability, effective electrical conductivity, and excellent percentage atom utilization. In the present study, the applicability of late first-row transition metals (Fe-Zn) decorated on the magnesium oxide nanocage (TM@Mg 12 O 12 ) as SACs for the HER has been studied, via density functional theory. The late first-row transition metals have been chosen as they have high abundance and are relatively low-cost. Among the studied systems, results show that the Fe@Mg 12 O 12 SAC is the best candidate for catalyzing the HER reaction as it exhibits the lowest activation barrier for HER. Moreover, Fe@Mg 12 O 12 shows high stability ( E int = -1.64 eV), which is essential in designing SACs to prevent aggregation of the metal. Furthermore, the results of the electronic properties' analysis showed that the HOMO-LUMO gap of the nanocage is decreased significantly upon doping of Fe (from 4.81 to 2.28 eV), indicating an increase in the conductivity of the system. This study highlights the potential application of the TM@nanocage SAC systems as effective HER catalysts., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

A very fascinating aspect in quantum chemical research is to determine the accurate and cost-effective methods for the calculation of electronic and structural properties through a benchmark study. The current study focuses on the performance evaluation of density functional theory methods for the accurate measurement of bond dissociation energies (BDEs) of chemically important M-O 2 bonds in water splitting reactions. The BDE measurement has got noteworthy attention due to its importance in all areas of chemistry. For BDE measurements of M-O 2 bonds in five metal complexes with oxygen molecules, 14 density functionals (DFs) are chosen from seven classes of DFs with two series of mixed basis sets. A combination of pseudopotential and Pople basis sets [LANL2DZ & 6-31G(d) and SDD & 6-31+G(d)] are used as a series of mixed basis sets. The B3LYP-GD3BJ functional with LANL2DZ & 6-31G(d) gives outstanding results due to low deviations, error, and the best Pearson's correlation ( R ) between the experimental and theoretical data. Our study suggested an efficient, low-cost, precise, and accurate B3LYP-GD3BJ/LANL2DZ & 6-31G(d) level of theory for BDE of the M-O 2 bond, which may be useful for chemists working in the field of energy generation and utilization., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

In this report, the geometric and electronic properties and static and dynamic hyperpolarizabilities of alkali metal-doped C 6 O 6 Li 6 organometallics are analyzed via density functional theory methods. The thermal stability of the considered complexes is examined through interaction energy ( E int ) calculations. Doping of alkali metal derives diffuse excess electrons, which generate the electride characteristics in the respective systems (electrons@complexant, e - @M@C 6 O 6 Li 6, M = Li, Na, and K). The electronic density shifting is also supported by natural bond orbital charge analysis. These electrides are further investigated for their nonlinear optical (NLO) responses through static and dynamic hyperpolarizability analyses. The potassium-doped C 6 O 6 Li 6 (K@C 6 O 6 Li 6 ) complex has high values of second- (β tot = 2.9 × 10 5 au) and third-order NLO responses (γ tot = 1.6 × 10 8 au) along with a high refractive index at 1064 nm, indicating that the NLO response of the corresponding complex increases at a higher wavelength. UV-vis absorption analysis is used to confirm the electronic excitations, which occur from the metal toward C 6 O 6 Li 6 . We assume that these newly designed organometallic electrides can be used in optical and optoelectronic fields for achieving better second-harmonic-generation-based NLO materials., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)