Spectroscopic, conformational analysis, structural benchmarking, excited state dynamics, and the photovoltaic properties of Enalapril and Lisinopril

Investigation on the molecular, electronic and spectroscopic properties of rosmarinic acid: an intuition from an experimental and computational perspective

Various drugs such as corticosteroids, salbutamol, and β2 agonist are available for the treatment of asthma an inflammatory disease and its symptoms, although the ingredient and the mode of action of these drugs are not clearly elucidated. Hence this research aimed at carrying out improved scientific research with respect to the use of natural product rosmarinic acid which poses minima, side effects. Herein, we first carried out extraction, isolation, and spectroscopic (FT-IR, 1H-NMR and 13C-NMR) investigation, followed by molecular modeling analysis on the naturally occurring rosmarinic acid extracted from Rosmarinus officinalis. A detailed comparison of the experimental and theoretical vibrational analysis has been carried out using five DFT functionals: BHANDH, HSEH1PBE, M06-2X, MPW3PBE and THCTHHYB with the basis set 6-311++G (d, p) to investigate into the structural, reactivity, and stability of the isolated compound. Frontier molecular orbital analysis and appropriate quantum descriptors were calculated. Results showed that the compound was more stable at M06-2X and more reactive at HSEH1PBE with an energy gap of 6.43441 eV and 3.8047 eV, respectively, which was later affirmed by the global quantum reactivity parameters. From natural bond orbital analysis, π* → π* is the major contributor to electron transition with the summation perturbation energy of 889.57 kcal/mol, while π → π* had the perturbation energy totaling of 145.3 kcal/mol. Geometry analysis shows BHANDH to have lower bond length values and lesser deviation from 120° in carbon-carbon angle. The potency of the title molecule as an asthma drug was tested via a molecular docking approach and the binding score of -8.2 kcal/mol was observed against -7.0 of salbutamol standard drug, suggesting romarinic acid as a potential natural organic treatment for asthma.Communicated by Ramaswamy H. Sarma.

Anti-inflammatory biomolecular activity of chlorinated-phenyldiazenyl-naphthalene-2-sulfonic acid derivatives: perception from DFT, molecular docking, and molecular dynamic simulation

In this study, two novel derivatives of naphthalene-2-sulfonic acid: 6-(((1S,5R)-3,5-dichloro-2,4,6-triazabicyclo [z3.1.0]hex-3-en-1-yl)amino)-5-((E)-phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS1) and (E)-6-((4,6-dichloro-1,3,5-triazine2-yl)amino)-4-hydroxy-3-(phenyldiazenyl)naphthalene-2-sulfonic acid (DTPS2) have been synthesized and characterized using FT-IR, UV-vis, and NMR spectroscopic techniques. Applying density functional theory (DFT) at the B3LYP, APFD, PBEPBE, HCTH, TPSSTPSS, and ωB97XD/aug-cc-pVDZ level of theories for the electronic structural properties. In-vitro analysis, molecular docking, molecular dynamic (MD) simulation of the compounds was conducted to investigate the anti-inflammatory potential using COXs enzymes. Docking indicates binding affinity of -9.57, -9.60, -6.77 and -7.37 kcal/mol for DTPS1, DTPS2, Ibuprofen and Diclofenac which agrees with in-vitro assay. Results of MD simulation, indicates sulphonic group in DTPS1 has > 30% interaction with the hydroxyl and oxygen atoms in amino acid residues, but > 35% interaction with the DTPS2. It can be said that the DTPS1 and DTPS2 can induce inhibitory effect on COXs to halt biosynthesis of prostaglandins (PGs), a chief mediator of inflammation and pain in mammals.Communicated by Ramaswamy H. Sarma.

Exploring the potential of single-metals (Cu, Ni, Zn) decorated Al12N12 nanostructures as sensors for flutamide anticancer drug

In recent years, scientists have been actively exploring and expanding biosensor technologies and materials to meet the growing societal demands in healthcare and other fields. This study aims to revolutionize biosensors by using density functional theory (DFT) at the cutting-edge B3LYP-GD3BJ/def2tzsvp level to investigate the sensing capabilities of (Cu, Ni, and Zn) doped on Aluminum nitride (Al12N12) nanostructures. Specifically, we focus on their potential to detect, analyze, and sense the drug flutamide (FLU) efficiently. Through advanced computational techniques, we explore molecular interactions to pave the way for highly effective and versatile biosensors. The adsorption energy values of -38.76 kcal/mol, -39.39 kcal/mol, and -39.37 kcal/mol for FLU@Cu-Al12N12, FLU@Ni-Al12N12, and FLU@Zn-Al12N12, respectively, indicate that FLU chemically adsorbs on the studied nanostructures. The reactivity and conductivity of the system follow a decreasing pattern: FLU@Cu-Al12N12 > FLU@Ni-Al12N12 > FLU@Zn-Al12N12, with a band gap of 0.267 eV, 2.197 eV, and 2.932 eV, respectively. These results suggest that FLU preferably adsorbs on the Al12N12@Cu surface. Natural bond orbital analysis reveals significant transitions in the studied system. Quantum theory of atom in molecule (QTAIM) and Non-covalent interaction (NCI) analysis confirm the nature and strength of interactions. Overall, our findings indicate that the doped surfaces show promise as electronic and biosensor materials for detection of FLU in real-world applications. We encourage experimental researchers to explore the use of (Cu, Ni, and Zn) doped on Aluminum nitride (Al12N12), particularly Al12N12@Cu, for biosensor applications.

Effect of conjugation length on fluorescence characteristics of carbon dots

The influence of sp2- and sp3-hybridized carbon coexisting in carbon cores on fluorescence characteristics of carbon dots (CDs) was revealed by density functional theory calculations. Based on the constructed coronene-like structures, the fluorescence emission spectra, transition molecular orbital pairs and several physical quantities describing the distribution of electrons and holes were investigated. The results indicate that due to the interaction between sp2 and sp3 carbon atoms, two main factors including the hyperconjugative effect and the separation of sp2 domain by sp3 carbon atoms can regulate the fluorescence wavelength. By analyzing the transition molecular orbital pairs, it was found that the fluorescence wavelength has a close correlation with the conjugation length, suggesting that the conjugation length can predict the shift of the emission spectra of CDs. The theoretical results provide a comprehensive understanding of fluorescence mechanism and help to synthesize CDs with expected fluorescence wavelength.

Yttrium- and zirconium-decorated Mg12O12-X (X = Y, Zr) nanoclusters as sensors for diazomethane (CH2N2) gas

Diazomethane (CH2N2) presents a notable hazard as a respiratory irritant, resulting in various adverse effects upon exposure. Consequently, there has been increasing concern in the field of environmental research to develop a sensor material that exhibits heightened sensitivity and conductivity for the detection and adsorption of this gas. Therefore, this study aims to provide a comprehensive analysis of the geometric structure of three systems: CH2N2@MgO (C1), CH2N2@YMgO (CY1), and CH2N2@ZrMgO (CZ1), in addition to pristine MgO nanocages. The investigation involves a theoretical analysis employing the DFT/ωB97XD method at the GenECP/6-311++G(d,p)/SDD level of theory. Notably, the examination of bond lengths within the MgO cage yielded specific values, including Mg15-O4 (1.896 Å), Mg19-O4 (1.952 Å), and Mg23-O4 (1.952 Å), thereby offering valuable insights into the structural properties and interactions with CH2N2 gas. Intriguingly, after the interaction, bond length variations were observed, with CH2N2@MgO exhibiting shorter bonds and CH2N2@YMgO showcasing longer bonds. Meanwhile, CH2N2@ZrMgO displayed shorter bonds, except for a longer bond in Mg19-O4, suggesting increased stability due to shorter bond distances. The study further investigated the electronic properties, revealing changes in the energy gap that influenced electrical conductivity and sensitivity. The energy gap increased for Zr@MgO, CH2N2@MgO, CH2N2@YMgO, and CH2N2@ZrMgO, indicating weak interactions on the MgO surface. Conversely, Y@MgO showed a decrease in energy, suggesting a strong interaction. The pure MgO surface exhibited the ability to donate and accept electrons, resulting in an energy gap of 4.799 eV. Surfaces decorated with yttrium and zirconium exhibited decreased energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), as well as decreased energy gap, indicating increased conductivity and sensitivity. Notably, Zr@MgO had the highest energy gap before CH2N2 adsorption, but C1 exhibited a significantly higher energy gap after adsorption, implying increased conductivity and sensitivity. The study also examined the density of states, demonstrating significant variations in the electronic properties of MgO and its decorated surfaces due to CH2N2 adsorption. Moreover, various analysis techniques were employed, including natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), and noncovalent interaction (NCI) analysis, which provided insights into bonding, charge density, and intermolecular interactions. The findings contribute to a deeper understanding of the sensing mechanisms of CH2N2 gas on nanocage surfaces, shedding light on adsorption energy, conductivity, and recovery time. These results hold significance for gas-sensing applications and provide a basis for further exploration and development in this field.

Identification of 3, 4-dihydroxy complexes as potential antiviral via DFT, molecular docking, molecular dynamics and MM/PBSA against rabies and dengue receptors

The quest to identify antiviral drug candidates for dengue and rabies viral diseases is a great challenge for the researchers. While different research is being conducted on the repurposed drugs against these two viruses, no drug compound has gained success in treating them. Therefore, in this study, 3, 4-dihydroxy complexes have been virtually designed to investigate their antiviral properties and analyze their efficiency in interaction with the concerned viral diseases. DFT calculations are carried out to study the electronic and thermodynamic properties to understand the stability and reactivity of the reported compounds. These compounds were subjected to molecular docking studies to understand the binding interactions with NS5 Dengue virus mRNA 2'-O-methyltransferase and phosphoprotein C-terminal domain of Rabies virus. MD simulation, hydrogen bond analysis, and MM/PBSA were performed at 100 ns to support the obtained docking results.Communicated by Ramaswamy H. Sarma.

Adsorption of air pollutants onto silver and gold atomic clusters: DFT and PNO-LCCSD-F12 calculations

We provide a comprehensive investigation of intermolecular interactions between atmospheric gaseous pollutants, including CH₄, CO, CO₂, NO, NO₂, SO₂, as well as H₂O and Ag_n (n = 1-22) or Au_n (n = 1-20) atomic clusters. The optimized geometries of all the systems investigated in our study were determined using density functional theory (DFT) with M06-2X functional and SDD basis set. The PNO-LCCSD-F12/SDD method was used for more accurate single-point energy calculations. Compared to their isolated states, the structures of the Ag_n and Au_n clusters undergo severe deformations upon adsorption of the gaseous species, which become more significant as the size of the clusters decreases. Considering that, in addition to adsorption energy, we have determined the interaction and deformation energy of all the systems. All our calculations consistently show that among the gaseous species examined, SO₂ and NO₂ exhibit a higher preference for adsorption on both types of clusters, with a slightly higher preference for the Ag clusters compared to the Au clusters, with the SO₂/Ag₁₆ system exhibiting the lowest adsorption energy. The type of intermolecular interactions was investigated through wave function analyses, including natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM), showing that NO₂ and SO₂ are chemisorbed on the Ag_n and Au_n atomic clusters, whereas the other gas molecules exhibit a much weaker interaction with them. The reported data can be used as input parameters for molecular dynamics simulations to study the selectivity of atomic clusters towards specific gases under ambient conditions, as well as to design materials that take advantage of the studied intermolecular interactions.

High-performance non-fullerene acceptor-analogues designed from dithienothiophen [3,2-b]-pyrrolobenzothiadiazole (TPBT) donor materials

CONTEXT

Density functional theory (DFT) method was employed to investigate the electronic structure properties, excited state dynamics, charge transfer, and photovoltaic potential of benzo [1,2,5] thiadiazole fused to 3,7-dimethyl-3a,6,7,7b-tetrahydro-5H-thieno[2',3':4,5]thieno[3,2-b]pyrrole to form 3,9,12,13-tetramethyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4,5]pyrrolo[3.2-g]thieno[2',3':4,5]thieno[3,2-b]indole as the acceptor (A), bridge with thiophene as π-spacer to the donor moieties (D) which are 2,3-dihydrobenzo [b]thiophene-6-carboxylic acid (M4) and functionalized R, M1, M2, M3, and M5 to give a D-π-A-π-D. Here is the reverse combination for our molecules: the A-π-D-π-A type of chromophore configuration. It is also observed that tuning the dono-bridge configuration significantly increases the ease of charge transfer as the energy gap decreases in the order of 1.29 eV in M4 < 1.59 eV in M3 < 1.67 eV < 1.99 in M2 and 2.06 eV. The reorganization energy (RE) of M3 (0.0031) and M5 (0.0031) indicates an increase in the order of M3 > M5 > R > M2 > M4 > M1. The HOMO-LUMO indicates that the reactivity decreased, while the stability increased for the reference R at 0.990 eV, compared to the designed molecules M1-M5, with M1 being the least stable at 0.970 eV, while M4 exhibited the highest stability at 1.550 eV. The stability of the designed molecule decreased in the order of M4:1.550 > M3:1.257 > M5:1.197 > M2:1.010 > M1:0.970. Therefore, all results point to the electron-deficient core as an effective end-capped electron acceptor in M1-M5 compounds. As the ideal pair for successfully optimizing optoelectronic properties by reducing the HOMO-LUMO energy levels, reorganization energy, and binding energy and enhancing the absorption maximum and open-circuit voltage values in these designed molecules.

METHODS

DFT and TDDFT calculations were performed with Gaussian 16 program. The modelled compounds were optimized fully using the CAM-B3LYP, WB97XD, B3LYP, and MPW1PW91 functionals with the 6-31 G (d,p) basis set. The graphs for the density of states were plotted using the PyMOlyze software. Other molecular properties like the transition density matrix (TDM) and electron density difference maps (EDD) were rendered via the Multiwfn software.

Assessing the Performance of Al12N12 and Al12P12 Nanostructured Materials for Alkali Metal Ion (Li, Na, K) Batteries

This study focused on the potential of aluminum nitride (Al₁₂N₁₂) and aluminum phosphide (Al₁₂P₁₂) nanomaterials as anode electrodes of lithium-ion (Li-ion), sodium-ion (Na-ion), and potassium-ion (K-ion) batteries as investigated via density functional theory (DFT) calculations at PBE0-D3, M062X-D3, and DSDPBEP86 as the reference method. The results show that the Li-ion battery has a higher cell voltage with a binding energy of -1.210 eV and higher reduction potential of -6.791 kcal/mol compared to the sodium and potassium ion batteries with binding energies of -0.749 and -0.935 eV and reduction potentials of -6.414 and -6.513 kcal/mol, respectively, using Al₁₂N₁₂ material. However, in Al₁₂P₁₂, increases in the binding energy and reduction potential were observed in the K-ion battery with values -1.485 eV and -7.535 kcal/mol higher than the Li and Na ion batteries with binding energy and reduction potential -1.483, -1.311 eV and -7.071, -7.184 eV, respectively. Finally, Al₁₂N₁₂ and Al₁₂P₁₂ were both proposed as novel anode electrodes in Li-ion and K-ion batteries with the highest performances.

First theoretical probe for efficient enhancement of optical nonlinearity via structural modifications into phenylene based D-π-A configured molecules

The design of nonlinear optical (NLO) materials using conjugated molecules via different techniques is reported in the literature to boost the use of these systems in NLO. Therefore, in the current study, designed phenylene based non-fullerene organic compounds with a D-π-A framework were selected for NLO investigation. The initial compound (PMD-1) was taken as a reference and its seven derivatives (PMDC2-PMDC8) were made by introducing different acceptor moieties into the chemical structure of PMD-1. To explain the NLO findings, frontier molecular orbital (FMO), transition density matrix (TDM), density of states (DOS), natural bond orbital (NBO) and UV-Vis study of the title compounds was executed by applying the PBE1PBE functional with the 6-311G(d,p) basis set. The descending order of band gaps (E gap) was reported as PMDC7 (2.656) > PMDC8 (2.485) > PMD-1 (2.131) > PMDC3 (2.103) > PMDC2 (2.079) > PMDC4 (2.065) > PMDC5 (2.059) > PMDC6 (2.004), in eV. Global reactivity parameters (GRPs) were associated with E gap values as PMDC6 with the lowest band gap showed less hardness (0.0368 E h) and high softness (13.5785 E h). The UV-Vis investigation revealed that the maximum λ max (739.542 nm) was exhibited by PMDC6 in dichloromethane (DCM) as compared to other derivatives. Additionally, natural bond orbital (NBO) based findings revealed that PMDC6 exhibited the highest stability value (34.98 kcal mol-1) because of prolonged hyper-conjugation. The dipole moment (μ), average linear polarizability 〈α〉, first hyperpolarizability (β tot) and second hyperpolarizability (γ tot) were evaluated for the reference and its derivatives. Consequently, among the designed compounds, the highest β tot (4.469 × 10-27 esu) and γ tot (5.600 × 10-32 esu) values were shown by PMDC6. Hence, it's concluded from said results that these structural modifications proved PMDC6 as the best second and third order NLO candidate for various applications like fiber optics, signal processing and data storage.

Detection of Carbon, Sulfur, and Nitrogen Dioxide Pollutants with a 2D Ca12O12 Nanostructured Material

In recent times, nanomaterials have been applied for the detection and sensing of toxic gases in the environment owing to their large surface-to-volume ratio and efficiency. CO₂ is a toxic gas that is associated with causing global warming, while SO₂ and NO₂ are also characterized as nonbenign gases in the sense that when inhaled, they increase the rate of respiratory infections. Therefore, there is an explicit reason to develop efficient nanosensors for monitoring and sensing of these gases in the environment. Herein, we performed quantum chemical simulation on a Ca₁₂O₁₂ nanocage as an efficient nanosensor for sensing and monitoring of these gases (CO₂, SO₂, NO₂) by employing high-level density functional theory modeling at the B3LYP-GD3(BJ)/6-311+G(d,p) level of theory. The results obtained from our studies revealed that the adsorption of CO₂ and SO₂ on the Ca₁₂O₁₂ nanocage with adsorption energies of -2.01 and -5.85 eV, respectively, is chemisorption in nature, while that of NO₂ possessing an adsorption energy of -0.69 eV is related to physisorption. Moreover, frontier molecular orbital (FMO), global reactivity descriptors, and noncovalent interaction (NCI) analysis revealed that the adsorption of CO₂ and SO₂ on the Ca₁₂O₁₂ nanocage is stable adsorption, while that of NO₂ is unstable adsorption. Thus, we can infer that the Ca₁₂O₁₂ nanocage is more efficient as a nanosensor in sensing CO₂ and SO₂ gases than in sensing NO₂ gas.

Heteroatoms (Si, B, N, and P) doped 2D monolayer MoS2 for NH3 gas detection

2D transition metal dichalcogenide MoS₂ monolayer quantum dots (MoS₂-QD) and their doped boron (B@MoS₂-QD), nitrogen (N@MoS₂-QD), phosphorus (P@MoS₂-QD), and silicon (Si@MoS₂-QD) surfaces have been theoretically investigated using density functional theory (DFT) computation to understand their mechanistic sensing ability, such as conductivity, selectivity, and sensitivity toward NH₃ gas. The results from electronic properties showed that P@MoS₂-QD had the lowest energy gap, which indicated an increase in electrical conductivity and better adsorption behavior. By carrying out comparative adsorption studies using m062-X, ωB97XD, B3LYP, and PBE0 methods at the 6-311G++(d,p) level of theory, the most negative values were observed from ωB97XD for the P@MoS₂-QD surface, signifying the preferred chemisorption surface for NH₃ detection. The mechanistic studies provided in this study also indicate that the P@MoS₂-QD dopant is a promising sensing material for monitoring ammonia gas in the real world. We hope this research work will provide informative knowledge for experimental researchers to realize the potential of MoS₂ dopants, specifically the P@MoS₂-QD surface, as a promising candidate for sensors to detect gas.

2D transition metal dichalcogenide MoS₂ monolayer quantum dots (MoS₂-QD) and their doped boron (B@MoS₂-QD), nitrogen (N@MoS₂-QD), phosphorus (P@MoS₂-QD), and silicon (Si@MoS₂-QD) counterparts are proposed as selective sensors for NH₃ gas.