A DFT study on electronic and optical properties of aspirin-functionalized B12N12 fullerene-like nanocluster

Exploring tiopronin adsorption on pristine and Al/Ga-doped boron nitride nanoclusters: A DFT approach for enhanced drug delivery

Tiopronin is a thiol-based medication recognized for its antioxidant properties, which may offer therapeutic benefits for various medical conditions. At present, it is utilized for the treatment of cystinuria and rheumatoid arthritis. However, its limited bioavailability poses a significant challenge for broader applications, necessitating high systemic doses to achieve localized therapeutic effects. The incorporation of a drug delivery system could help overcome this issue by allowing for controlled and targeted release. Functionalized B12N12 fullerenes present a promising platform with substantial potential for biomedical applications, particularly in drug delivery. In this study, the effect of loading the tiopronin drug on the structural and electronic properties of pure B12N12, AlB11N12 and GaB11N12 fullerenes nano agent were evaluated using density functional theory in both gas and aqueous environments. The adsorption energy of tiopronin over the fullerenes has been studied through its nucleophilic sites (COOH, NH2, CO, and SH). Based on our analysis, the adsorption energies are about -1.69, -3.38 and -1.96 eV for the most stable complexes of B12N12, AlB11N12 and GaB11N12, respectively. Electronic analysis showed that the HOMO-LUMO gaps decrease upon drug adsorption, resulting in significant changes in molecular orbital levels and quantum molecular descriptors. Additionally, quantum theory of atoms in molecules (QTAIM) analysis, electron localization function (ELF), and reduced density gradient (RDG) plots were explored to investigate interaction properties.

Understanding the adsorption performance of hetero-nanocages (C12-B6N6, C12-Al6N6, and B6N6-Al6N6) towards hydroxyurea anticancer drug: a comprehensive study using DFT

Cancer is a paramount health challenge to global health, which forms tumors that can invade nearby tissues and spread to neighboring cells. Recently, nanotechnology has been used to control the growth of cancer, in which anticancer drugs are delivered to cancerous cells via nanoparticles without damaging healthy tissues. In this study, DFT investigations were carried out to examine the adsorption behavior of C24, B12N12, and Al12N12 nanocages as well as their heterostructures C12-B6N6, C12-Al6N6, and B6N6-Al6N6 towards the hydroxyurea (HU) anticancer drug. In this regard, adsorption energy, interaction distance between the drug and nanocages, charge transfer, energy gap, dipole moment, quantum molecular descriptors, work function, and COSMO surface analysis were analyzed to understand their adsorption performance. Findings demonstrate that the adsorption energies of two hetero-nanocages on their hexagonal (SH) and tetragonal (ST) sites are favorable for the drug delivery process. The computed adsorption energy of B6N6-Al6N6 of the ST/AlN site is 183.59 kJ mol-1, which is higher than that of the C12-Al6N6 nanocage, including minimum adsorption distances. Negative adsorption energy with low adsorption distances implies an attractive interaction between the drug and nanocages. During the interaction, a significant amount of charge is transferred between the drug and nanocages. Furthermore, for both complexes, larger dipole moments were observed in water media compared to gas media. From DOS spectra, prominent peaks were found in the Fermi level after adsorption of HU on the nanocages, implying the reduction of the energy gap. Noticeable overlaps between the PDOS spectra of the nanocages and HU's close contact atom demonstrate the formation of chemical bonds between two specific atoms. Therefore, it can be concluded that among the nanocages, C12-Al6N6 and B6N6-Al6N6 may be suitable carriers for HU drug.

Adsorption of drugs on B12N12 and Al12N12 nanocages

The adsorption behavior of twelve drug molecules (5-fluorouracil, nitrosourea, pyrazinamide, sulfanilamide, ethionamide, 6-thioguanine, ciclopirox, 6-mercaptopurine, isoniazid, metformin, 4-aminopyridine, and cathinone) on B12N12 and Al12N12 nanocages was studied using density functional theory. In general, the drug molecules prefer to bind with the boron atom of the B12N12 nanocage and the aluminium atoms of the Al12N12 nanocage. However, a hydrogen atom is transferred from each of 5-fluorouracil, nitrosourea, 6-thioguanine, ciclopirox, and 6-mercaptopurine to the nitrogen atom of the Al12N12 nanocage. All the drug molecules are found to be chemisorbed on the B12N12 and Al12N12 nanocages. The adsorption energies of the drug/B12N12 system are linearly correlated with the molecular electrostatic potential minimum values of the drug molecules. The transfer of the hydrogen atom from the drug molecules to the nitrogen atom of the Al12N12 nanocage leads to relatively high adsorption energies. We observed significant changes in the reactivity parameters (e.g. electronic chemical potential) of the nanocages due to the chemisorption process. Overall, the QTAIM analysis indicates that the interactions between drug molecules and nanocages have a partial covalent character. Among the studied systems, the adsorption process was more spontaneous for the ciclopirox/Al12N12 system in water.

Exploring the promising application of Be12O12 nanocage for the abatement of paracetamol using DFT simulations

The removal of paracetamol from water is of prime concern because of its toxic nature in aquatic environment. In the present research, a detailed DFT study is carried out to remove paracetamol drug from water with the help of Be12O12 to eliminate the related issues. Three different geometries (CMP-1, CMP-2, CMP-3,) are obtained with the highest adsorption energies value (Eads) of - 31.2316 kcal/mol for CMP-3 without any prominent structural change. It is observed from the study that O atom from the carbonyl group (C=O) and H atom from O-H group successfully interact with O and Be atoms of the nanocage respectively. Natural bonding orbitals analysis reveals charge transfer to paracetamol drug from Be12O12 nanocage with maximum charge transfer of - 0.159 e for CMP-3 with bond angle of 1.65 Å confirming the stability of the CMP-3 among the optimized complexes. The quantum theory of atoms in molecule concludes that the interaction between paracetamol drug molecule and Be12O12 is purely closed-shell weak electrostatic in nature in CMP-1 and CMP-3 and shared interaction in CMP-2. The thermodynamics analysis witnesses that the process is exothermic and spontaneous. The regeneration study reveals the reversible nature of the adsorbent. The overall study presents Be12O12 nanocage as a potential adsorbent and may be used in future for the purification of water from a number of emerging pollutants.

Ibuprofen adsorption and detection of pristine, Fe-, Ni-, and Pt-doped boron nitride nanotubes: A DFT investigation

The main challenge has been focused on ibuprofen drug detection and adsorption of boron nitride nanotube (BNNT) doping with transition metal (TM = Fe, Ni, and Pt) atoms using the density functional theory calculation in gas and water phases. The geometrical structures, adsorption energies, solvation energies, and electronic properties were examined. The optimized geometries show that the ibuprofen molecule oriented itself at different bond distances and angles with respect to BNNT surface. The calculated results display exothermic adsorption processes for all ibuprofen/BNNT and ibuprofen/TM-doped BNNT complexes. Ibuprofen molecule can absorb on the Fe-, Ni-, and Pt-doped BNNTs via a stronger interaction than those of pristine BNNT in both gas and water phases in which the Fe doping on N site of BNNT shows the strongest interaction with ibuprofen molecule. The H (head) site of ibuprofen molecule to BNNT surface shows stronger interaction than M (middle) and T (tail) sites. The short of adsorption distance and the large of charge transfer correspond to the high adsorption strength of TM-doped BNNTs toward ibuprofen molecule. Charge analysis confirms the partial charge transfer occurring from the ibuprofen molecule to the BNNTs. The solvation energies in water solution reveal that the ibuprofen molecule adsorbed on TM-doped BNNTs is more soluble than pristine BNNT. The work functions of BNNTs are reduced by ibuprofen adsorption. A short recovery times and suitable desorption temperatures are observed for the ibuprofen desorption on pristine BNNT and TM-doped BNNT surfaces. After ibuprofen adsorption, the energy levels and energy gaps of Fe-, Ni-, and Pt-doped BNNTs are changed in which Ni doping on B atom of BNNT displays the largest change. The quantum molecular characteristics of BNNT will be changed after ibuprofen adsorption. The orbital distributions are occurred around the ibuprofen molecule and doping site. The alteration in the density of states for TM-doped BNNT is considerably more pronounced compared to the pristine BNNT. Drawing from the achieved outcomes, it can be inferred that when employed for the delivery of ibuprofen in biological media, Fe-, Ni-, and Pt-doped BNNTs exhibits the greater suitability for the adsorption and detection of the ibuprofen molecule compared to pristine BNNT.

Interaction of Anagrelide drug molecule on pristine and doped boron nitride nanocages: a DFT, RDG, PCM and QTAIM investigation

Nowadays, a nanostructure-based drug delivery system is one of the most noticeable topics to be studied, and in this regard, boron nitride nanoclusters are promising drug carriers for targeted drug delivery systems. In this article, the interaction mechanism of Anagrelide (AG) drug with B12N12 and Al- and Ga-doped B12N12 nanocages have been investigated using DFT with B3LYP/6-31 G (d, p) method in both gas and water media. All our studied complexes are thermodynamically stable, and doped nanocage complexes have higher negative adsorption energy (EAd.) and negative solvation energy than AG/B12N12 complexes which correspond to the stability of these systems in both media. The negative highest EAd value is 64.98 kcal/mol (63.17 kcal/mol) and 65.69 kcal/mol (65.11 kcal/mol) in gas (water) media for complex F (AG/AlB11N12) and complex I (AG/GaB11N12) respectively, which refers to the highest stability of these systems. The enhanced values of dipole moment (from 12.40 (12.65) Debye to 17.21 (17.69) Debye in complex F (complex I)) also confirm their stability. The QTAIM and RDG analysis endorse the strong adsorption nature of the AG drug onto the AlB11N12, and GaB11N12 nanocages, which is consistent with the adsorption energy as chemisorption occurs for these complexes. According to the electronic properties, doped nanocages show high sensitivity that infers their promising nature for drug delivery purposes. Thus, complex F and complex I are promising drug delivery systems, and doped nanocages (AlB11N12 and GaB11N12) are better carriers than pristine nanocages for the AG drug delivery system.Communicated by Ramaswamy H. Sarma.

Investigation of the substituted-titanium nanocages using computational chemistry

We are investigated substitution effects of titanium heteroatoms on band gap, charge and local reactivity of C_20-nTi_n heterofullerenes (n = 1-5), at different levels and basis sets. The C₁₈Ti_2-2 nanocage is considered as the most kinetically stable species with the widest band gap of 2.86 eV, in which two carbon atoms are substituted by two Ti atoms in equatorial position, individually. The charges on carbon atoms of C₂₀ are roughly zero, while high positive charge (1.256) on the surface of C₁₉Ti₁ prompts this heteofullerene for hydrogen storage. The positive atomic charge on Ti atoms and negative atomic charge on their adjacent C atoms implies that these sites can be influenced more readily by nucleophilic and electrophilic regents, respectively. We examined the usefulness of local reactivity descriptors to predict the reactivity of Ti-C atomic sites on the external surface of the heterofullerenes. The properties determined include Fukui function (F.F.); f (k) and local softness s (k) on the surfaces of the investigated hollow cages. Geometry optimization results reveal that titanium atoms can be comfortably incorporated into the CC network of fullerene. It is most likely associated with the triple-coordination characteristic of titanium atoms, which can well match with the sp²-hybridized carbon bonding structure. According to the values of f (k) and s (k) for the C₁₅Ti₅ heterofullerene; the carbon atoms in the cap regions exhibit a different reactivity pattern than those in the equatorial portion of the heterofullerene. The titanium impurity can significantly improve the fullerene's surface reactivity and it allows controlling their surface properties. The band gap of C_20-nTi_n …..(H₂)_n structures is decreased with increasing n. Hence, C₁₅Ti₅ is found as the best hydrogen adsorbent.

C-PCM study on the electronic and optical properties of Fe(CO)4B12N12 complexes

We explored solvent effect on the stability, dipole moment, polarizability and first hyperpolarizability of Fe(CO)4B12N12 complexes at MPW1PW91/6-311G(d,p) level of theory. These complexes were considered in the low spin states. The self-consistent reaction field theory (SCRF) based on conductor-like polarizable continuum model (PCM) was employed to illustration of the solvent influences. The relations between the parameters with solvent polarity functions (McRae and Suppan functions) were given. Also, relations of the wavenumbers values of the stretching of carbonyl ligands with the Kirkwood–Bauer–Magat equation (KBM) were provided.

Potential sensing of toxic chemical warfare agents (CWAs) by twisted nanographenes: A first principle approach

The toxic chemical warfare agents (CWAs) are extremely harmful to the living organisms. Their efficient detection and removal in a limited time span are essential for the human health and environmental security. Twisted nanographenes have great applications in the fields of energy storage and optoelectronics, but their use as sensors is rarely described. Therefore, we have explored the sensitivity and selectivity of twisted nanographene analogues (C₃₂H₁₆, C₆₄H₃₂) towards selected toxic CWAs, including phosgene, thiophosgene and formaldehyde. The interaction between CWAs and twisted nanographenes is mainly interpreted by considering the optimized geometries, adsorption energies, natural bond orbital (NBO), frontier molecular orbital (FMO), non-covalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analyses. The structural geometries show that the central octagon of twisted nanographenes is the most favorable site of interaction. The interaction energies reveal the physisorption of selected CWAs on tNGs surface. The average energy gap change (%E_H-L^a) and % sensitivity are quantitatively determined to evaluate the sensing capability of the twisted nanographenes. Among the selected CWAs molecules, the sensitivity of tNG analogues (C₃₂H₁₆ and C₆₄H₃₂) is superior towards thiophosgene (ThP), which is revealed by the high interaction energies of -8.19 and - 12.17 kcal/mol, respectively. This theoretical study will help experimentalists to devise novel sensors based on twisted nanographenes for the detection of toxic CWAs which may also work efficiently under the humid conditions.

DFT investigation on the application of pure and doped X12N12 (X = B and Al) fullerene-like nano-cages toward the adsorption of temozolomide

The sensitivity of pure and doped X₁₂N₁₂ (X = B and Al) fullerene-like nano-cages (FLNs) toward the anti-cancer drug temozolomide (TMZ) is probed herein at DFT/M06-2X-D3/6-311G(d,p) theoretical level in both gas phase and water. A noticeable affinity of the FLNs toward TMZ was observed along with the negative gas-phase adsorption energies -1.37 and -2.09 eV for the most stable configurations of pure B₁₂N₁₂ and Al₁₂N₁₂ pristines, respectively. Considerable charge transfer from TMZ to the FLNs was also revealed via NBO analysis and the Hirshfeld atomic charges, making the dipole moment vector of the molecular complexes to be oriented from the nano-cages to the TMZ moiety. Furthermore, a percentage decrease in the HOMO-LUMO energy gap (ΔE _g) of 38.09 and 17.72% was obtained for the B₁₂N₁₂ and Al₁₂N₁₂ nano-cages, respectively. The percentage change in ΔE _g was found to be reduced upon doping and solvation of the FLNs. Finally, a recovery time in vacuum ultraviolet light of 1.06 s is found for the complex with pure B₁₂N₁₂, which in addition to the above-mentioned parameters make this boron nitride cage the best sensor for TMZ, among the FLNs considered in the present work.

Density functional theory studies on C20 with substitutional TinNn impurities

In this paper, we have performed systematic theoretical surveys of C₂₀ and its C_20-2nTi_nN_n nanocages with n = 1-8 at DFT. Full optimization indicates none of the structures collapse to open deformed as segregated heterofullerene. Also, in order to avoid the resulted strain of fused five-pentagon configuration, some of them deform their cage at the Ti-N bonds and appear cubic-like. Binding energy (E_b) increases, and the absolute heat of atomization │ΔH_at│ of the designed C_20-2nTi_nN_n structures decreases, respectively, as the number of substituting Ti-N units increases. The calculated E_b of 57.05 eV/atom and │ΔH_at│ of 2437.40 kcal/mol display C₄Ti₈N₈ as the most thermodynamic stable heterofullerene where including eight separated Ti-N units through two double C═C bonds. In contrast, the calculated band gap of 2.06 eV shows C₁₈Ti₁N₁ as the best-insulated heterofullerene. Here isolable or extractable open-shell C₁₈Ti₁N₁ heterofullerene must be kinetic stable species, and closed-shell C₄Ti₈N₈ should be thermodynamic stable species. Compared to the suggested Ti-decorated B₃₈ fullerene as a high capacity hydrogen storage material with large E_b (5.67 eV/atom), our studied C_20-2nTi_nN_n heterofullerenes show the higher E_b with a range of 13.78 to 57.05 eV/atom, the higher stability, and the higher capacity hydrogen storage. Each Ti-N unit can bind up to two hydrogen molecules with an average adsorption energy of 0.073 eV/H₂. While the C₄Ti₈N₈ fullerene substituted with 8 Ti-N units can store 16 H₂ molecules, the hydrogen gravimetric density (the hydrogen storage capacity) reaches up to 5.61 wt% with an average adsorption energy of 0.587 eV/H₂. Based on these results, we infer that C₄Ti₈N₈ fullerene is a potential material for hydrogen storage with high capacity and might motivate active experimental efforts in designing hydrogen storage media.

N/OB dative bond supplemented by N-HN/HC Hydrogen Bonds make BN-cages an attractive candidate for DNA-nucleobase adsorption – An MP2 prediction

The response of B12N12-nanocage towards DNA-nucleobases (adenine, guanine, cytosine, and thymine) is investigated using MP2 and DFT (M06-2X) levels of theory with 6-311+G** basis set. Multiple BN-cage-nucleobase structures for each...

Investigation of the adsorption properties of gemcitabine anticancer drug with metal-doped boron nitride fullerenes as a drug-delivery carrier: a DFT study

Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects. Hence in this work, the applications of nanostructures as anticancer drug-delivery carriers were widely investigated to target cancerous tissues. Based on DFT calculations, we investigated the transition metal-doped boron nitride nanostructure as a drug-delivery agent for the gemcitabine drug utilizing the B3LYP/6-31G (d, p) level of theory. In this research, the adsorption energy and electronic parameters of gemcitabine on the interaction with the metal-doped BN nanostructures were studied. It has been observed that metal doping significantly enhances the drug-delivery properties of BN nanostructures. Among the investigated nanostructures, Ni–BN has been found to be the most prominent nanostructure to transport gemcitabine with an elevated value of adsorption energy in both the gas phase (−45.79) and water media (−32.46). The interaction between gemcitabine and BN nanostructures was confirmed through frontier molecular orbitals and stabilization energy analysis. The fractional charge transfer, MEP, NCI, and NBO analyses exposed the charge transfer from drug molecule to the BN nanostructures. Transition density maps and UV-VIS spectra were also plotted to investigate the excited-state properties of the designed complexes. Thus, the present study provides an in-depth interaction mechanism of the gemcitabine drug with BN, which reveals that metal-doped BN nanostructures can be a favorable drug-delivery vehicle for the gemcitabine anticancer drug.

Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects.

Computational investigation of interaction between titanocene dichloride and nanoclusters (B12N12, B12P12, Al12N12 and Al12P12)

This study investigated the interactions between B12N12, B12P12, Al12N12 and Al12P12 nanoclusters and titanocene dichloride anticancer drug complex using B3P86 functional. The bonding interaction between the nano-clusters and anticancer drug were examined through energy decomposition analysis (EDA). A good quadratic equation between interaction energy and molar volume (Vm) were provided. Charge transfer between fragments were illustrated with electrophilicity-based charge transfer (ECT). According to calculations, the values of heat of formation of the studied systems were negative (exothermic), which shows that these molecules are thermodynamically stable. The relationship between molar refractivity (MR) and Vm presented linear correlation.

Substitution effects via aromaticity, polarizability, APT, AIM, IR analysis, and hydrogen adsorption in C20-nTin nanostructures: a DFT survey

In this paper, the substitution effects of titanium heteroatom(s) on aromaticity, the average isotropic polarizability (< α >), the atomic polar tensor (APT) charge, the electrostatic potential (ESP) map, and the atoms in molecule (AIM) analysis along with infrared (IR) spectroscopy of C₂₀ fullerene and its C_20-nTi_n derivatives (n = 1-5) are probed via density functional theory (DFT). The nucleus-independent chemical shifts (NICS) specify that substitution effect causes more aromaticity character of the optimized heterofullerenes than benzene molecule and higher APT charge distribution upon surfaces of them than pure cage. The highest negative and positive APT charge distribution on carbons of C₁₅Ti₅ and titanium substitutions of C₁₆Ti_4-2 implies that these sites can be attacked more readily by electrophilic and nucleophilic regents, respectively. We are very pleased to state that isolating the Ti-Ti single bonds by intermediacy of one or two C atoms is an applicable strategy for attaining the highest APT charge distribution on Ti atoms of C₁₆Ti_4-2 as suitable hydrogen storage. AIM analysis of the studied C_20-nAl_n derivatives signifies the highest electron density (ρ (r)) of 0.294 a.u. and the highest positive Laplacian of electron density (∇²ρ (r)) of 0.190 a.u., at bond critical points (BCPs) of C-Ti bond in the most stable C₁₉Ti₁ species. This heterofullerene shows the lowest < α > between the studied structures. IR spectroscopy shows that exclusive of C₁₆Ti_4-1 (as transition state), the other optimized hollow cages (as global minima) have no imaginary frequency.

The interaction between carboplatin anticancer drug and B12N12 nano-cluster: A computational investigation

This study investigated the interaction between B12N12 nano-cluster and carboplatin complex using B3P86 functional. Two interaction modes between B12N12 nano-cluster and carboplatin complex were considered. The bonding interaction between the B12N12 nano-cluster and carboplatin complex was examined through energy decomposition analysis (EDA). Also, Shubin Liu’s energy decomposition analysis (EDA-SBL) is used to study the source of energy differences between various isomers of B12N12 ...  carboplatin complex. Charge transfer between fragments were illustrated with electrophilicity-based charge transfer (ECT) and extended charge decomposition analysis (ECDA). The quantum theory of atoms in molecules (QTAIM) analysis was applied to assess the Pt-B and Pt-N bonds within B12N12 ...  carboplatin complex.

Adsorption behavior of mercaptopurine and 6-thioguanine drugs on the B12N12, AlB11N12 and GaB11N12 nanoclusters, a comparative DFT study

Lately, drug delivery systems established on nanostructures have become the most proficient to be studied. There are different studies suggested that the BN nanoclusters can be used as drug carriers and transport drugs in the target cell. Therefore, the interactions and adsorption behavior of Mercaptopurine (MC) and 6-thioguanine (TG) as anti-cancer drugs on the B₁₂N₁₂ (BN), AlB₁₁N₁₂ (AlBN) and GaB₁₁N₁₂ (GaBN) nanoclusters were studied by density functional theory (DFT) and quantum mechanics atoms in molecules (QMAIM) methods to find a new drug delivery system. Our results showed strong adsorption obtained in BN-MC/TG and AlBN-MC/TG complexes can be decomposed by the BN and AlBN indicating that these nanostructures are not suitable in drug efficiency of MC and TG drugs. Unlike the BN and AlBN nanoclusters, GaBN significantly makes the MC and TG drugs adsorption energetically favorable. The high solvation energy of GaBN when interacting with MC and TG drugs led it to applicability as nanocarriers for these drugs in the drug delivery systems. Furthermore, GaBN has a short recovery time for MC, and TG drugs desorption compared to BN and AlBN nanoclusters. It is predicted that the MC, and TG drugs over GaBN can be used as a drug delivery system.Communicated by Ramaswamy H. Sarma.

Characterization of titanium influences on structure and thermodynamic stability of novel C20-nTin nanofullerenes (n=1-5): a density functional perspective

In this survey, effects of titanium heteroatom(s) on structural parameters and thermodynamic stability of C₂₀ fullerene and its C_20-nTi_n derivatives (n = 1-5) are compared and contrasted, at DFT levels of theory. The results show that in going from C₁₉Ti₁ to C₁₅Ti₅, binding energy increases while absolute value heat of atomization decreases. According to vibrational frequency analysis, excepting C₁₆Ti_4-1, the other optimized structures give no imaginary frequency as true minima. The calculated binding energy of 887.12 kcal mol^-1/atom displays C₁₅Ti₅ as the most thermodynamically stable heterofullerene. It has C_s symmetry and contains five titanium atoms alternatively in equatorial position. The substitutional doping of C₂₀ fullerene leads to high Mülliken charge distribution upon the surfaces of the resulted heterofullerenes especially C₁₉Ti₁ as suitable hydrogen storage. The contour plots indicate the most negative electrostatic potential by red color for C atoms, whereas the most positive electrostatic potential by yellow color for Ti heteroatoms. The contour plots and multiwfn analysis exhibit charge transfer from titanium heteroatoms to the neighboring carbon atoms. Furthermore, the resulted electron density maps from multiwfn qualitatively confirm the contour plot's findings. The hydrogen adsorption is an endothermic process for C₂₀ fullerene and exothermic process for C_20-nTi_n heterofullerenes. Major criteria examined for thermodynamic stability; from C₁₉Ti₁ to C₁₅Ti₅, binding energy and hydrogen adsorption increase while heat of atomization decreases.

Thermodynamic stability, structural and electronic properties for the C20-nAln heterofullerenes (n = 1-5): a DFT study

DFT calculations are utilized to compare and contrast the substituted aluminum-heterofullerenes, C_20-nAl_n (with n = 1-5) from thermodynamically view point, at density functional theory (DFT). Vibrational frequency analysis confirms that apart from C₁₅Al₅, all studied species are true minima. Considering the optimized geometries shows that all heterofullerenes are isolated-pentagon cage and none collapse to open deformed as segregated structure. The highest binding energy (5.56 eV/atom) and absolute heat of atomization (3323.68 kcal mol^-1) reveals open-shell C₁₉Al₁ as the most stable thermodynamic heterofullerene. The most NICS (0) (isotropic and anisotropic parameters, -49.58 and - 46.47 ppm, respectively) introduces closed-shell C₁₈Al_2-2 as the most aromatic structure. Also, closed-shell C₁₆Al_4-1 heterofullerene emerges with the most polarizability (307.71 a.u.) and hence activity to interact with the surrounding polar species. The lowest and the highest charge transfer on the surfaces of C₂₀ and C₁₆Al_4-2 without weak Al-Al bond, as the worst and the best candidate, respectively, provokes further investigation on impossible and possible application for hydrogen storage, respectively. We wish that the present survey will stimulate new experiments.

Theoretical Study on the Nonlinear Optical Property of Boron Nitride Nanoclusters Functionalized by Electron Donating and Electron Accepting Groups

The influence of donor-acceptor (D-A) groups on the nonlinear optical (NLO) property of B₁₂N₁₂ functionalized nanocluster has been investigated by density functional theory. We study the effect of bonding of three electron acceptor ligands (CN, COOH, and NO₂) and three donor ligands (NH₂, N(CH₃)₂, and PhNH₂) positioned at opposite ends of B₁₂N₁₂ nanocluster in the gas phase. The result reveals that the complexation of D-A groups on the B₁₂N₁₂ nanocluster is energetically favorable and significantly narrowed the HOMO-LUMO gaps. The functionalization of D-A groups lead to an extremely large first hyperpolarizability value. Our survey reports the strongest NLO responses found in PhNH₂-B₁₂N₁₂-PhCN cluster (1882.47 × 10^-30 esu), whereas centrosymmetric B₁₂N₁₂ cluster yields a zero hyperpolarizability value. Designed systems are analyzed through the HOMO-LUMO gap, frontier molecular orbital, hyperpolarizability, Δr index, transition dipole moment density, density of states (DOS), and molecular electrostatic potential. The obtained results are well correlated with the computed absorption spectra of the molecule. The results demonstrate that phenyl ring incorporated D-A groups amplify the NLO response to a larger extent. The significant first hyperpolarizability arises due to charge transfer from the donor to the acceptor moiety. As a whole, this theoretical work provides a direction to researchers that the right choice of substitution can considerably impact the nonlinear optical property of BN nanoclusters.

Efficient Cu Decorated Inorganic B12P12 Nanoclusters for Sensing Toxic COCl2 Gas: A Detailed DFT Study

Gas sensing materials have been widely explored recently owing to their versatile environmental and agriculture monitoring applications. Phosgene (COCl2) is a toxic and harmful gas, therefore, a reliable and sensitive technique is required for monitoring its quantity in the atmosphere. In this study, pure as well as copper decorated B[Formula: see text]P[Formula: see text](Cu-BP) nanoclusters were analyzed using DFT method to investigate their specific potential for phosgene gas adsorption. Cu interaction resulted in three optimized geometries S1, S2 and S3 with interaction energies of [Formula: see text]234.52[Formula: see text]kJ/mol, [Formula: see text]214.59[Formula: see text]kJ/mol and [Formula: see text]266.45[Formula: see text]kJ/mol, respectively. In all these three cases, the COCl2 prefers to interact at the top of the cage. The phosgene molecule (COCl2) interacts with bare nanocage at a distance of 3.22[Formula: see text]Å with interaction energy of [Formula: see text]6.22[Formula: see text]kJ/mol, while the observed interaction energies of phosgene at Cu decorated B[Formula: see text]P[Formula: see text] are [Formula: see text]76.90[Formula: see text]kJ/mol, [Formula: see text]119.03[Formula: see text]kJ/mol and [Formula: see text]29.60[Formula: see text]kJ/mol, respectively. To observe the variations in electronic structure, fermi level, molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs), natural bonding orbital ([Formula: see text]), softness, hardness, chemical potential and electrophilicity are calculated before and after phosgene adsorption. Energy gap reduce significantly after phosgene adsorption from 2.31[Formula: see text]eV, 2.05[Formula: see text]eV and 2.46[Formula: see text]eV to 1.54[Formula: see text]eV, 1.57[Formula: see text]eV and 2.45[Formula: see text]eV, respectively. Results of all analysis suggested that decoration of Cu significantly enhanced the adsorption power of B[Formula: see text]P[Formula: see text] nan-cluster for COCl2 molecule. Therefore, the Cu-decorated B[Formula: see text]P[Formula: see text] nanocages are considered as potential candidates for application in COCl2 sensors.

Adsorption of Celecoxib on B12N12 fullerene: Spectroscopic and DFT/TD-DFT study

In this study, we evaluated the effect of the Celecoxib (CXB) adsorption on the electronic and optical properties of B₁₂N₁₂ fullerene by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations with the M06-2X functional and the 6-311+G** basis set. The calculated adsorption energies of CXB with the B₁₂N₁₂ fullerene was evaluated at T = 298.15 K in the vacuum and solvent (water) environments with the M06-2X functional. UV absorption and IR spectra were calculated and studied in order to identify the most important changes happening as a consequence of interactions between CXB and B₁₂N₁₂ fullerene. The results revealed that the adsorption of the CXB molecule from its NH₂ head on the B₁₂N₁₂ is more favorable than those of the SO₂ and NH groups in the gas and solvent environments. It is anticipated that the applied B₁₂N₁₂ fullerene could be suitable as a biomedical carrier for the delivery of CXB drug.