NBO Charge Analysis Research Articles

Synthesis, characterization, in silico and in vitro assessment of 2-aminopyridine nicotinamide cocrystal as a new agent for breast cancer therapy

Breast cancer is the leading cause of cancer-related death among women globally, in spite of major advances in diagnosis and treatment. 2-Aminopyridine Nicotinamide (2APNA) cocrystal was synthesized and cocrystal formation was confirmed through powder XRD. Computational investigations in structural fields and spectroscopic parameters were conducted and compared with the experimental results. Comparing the optimized geometrical characteristics, it was observed that molecular properties of 2APNA closely match the previously reported experimental data. FT-IR and FT-Raman spectroscopic analysis revealed the theoretical wavenumbers agree better with recorded data and in UV–visible absorption a single peak was recorded at 247 nm showing n → π* transition. The 2APNA's stability, reactive nature, charge relocations were studied through quantum chemical calculation such as FMO, MEP, NBO, NLO and Mulliken charge analysis. The topological features of cocrystal 2APNA was examined through ELF, LOL and RDG studies. The anti-apoptotic protein BCL-2 was selected as a target in molecular docking analysis and the results expressed 2APNA's binding score as -8.2 kcal/mol. In vitro studies confirmed that 2APNA has 2APNA demonstrated an enhanced cell death in MCF-7 cells with the IC50 concentration of 56.58 µg/mL and decreased the expression of BCL-2, thus resulting in apoptotic cell death. These results indicated that 2APNA possess a potent anticancer property for the treatment of breast cancer.

Analysis of electronic properties and sensing applications in Graphene/BC3 heterostructures

Many research studies have been conducted into the applications of the heterostructures of graphene (Gr) and boron carbide (BC3) in real-world devices after they were synthesized successfully by researchers. Thanks to their unique electronic attributes and high surface-to-volume ratio, the above-mentioned two-dimensional nanosheets (NSs) such as have enjoyed the interest of many research groups and scientists. Within this piece of research, the electronic and structural attributes of pure Gr (PGr), pure BC3 (PBC3) and their in-plane heterostructures were investigated by employing the DFT along with the density functionals B3LYP and WB97XD. The results demonstrated that by increasing the concentration of the B-C, there was a gradual increase in the bandgap. Also, the structural stability of the NSs was good and the cohesive energy was favourable. In addition, the adhesion attributes of these NSs were investigated towards two toxic gasses, namely CO and SO2. Amongst the heterostructures, after exposure to CO and SO2, the adhesion energy of GBC3I was greater, which was approximately −0.487 eV and −0.229 eV, respectively. Following the adhesion of SO2 onto the surface of the NSs, apart from the PGr, there was a significant change in their electronic attributes such as conductance, workfunction, Fermi level, the LUMO, the HOMO and the bandgap. However, following the adhesion of CO, the above-mentioned attributed remained almost the same. Based on the NBO and Mulliken charge analysis, there was a charge transport from the gasses to the NSs. Despite the fact that the adhesion energies for CO were relative higher than the adhesion energies for SO2for the NSs, the analysis of the MEP maps, the charge transport and the electronic attributes demonstrated that the NSs can be used as promising nanosensors for the detection of SO2 rather than CO.

Study on the electronic structures and NLO properties of C6H6F6 doped superalkalis X3M (X=Li, na, K; M=O, S, Se)

To explore novel high-performance nonlinear optical (NLO) materials, this paper focuses on studying and discussing the geometric, electrical, and NLO properties of superalkali-doped C6H6F6. Geometrical and thermodynamic properties have been calculated by density-functional theory (DFT) calculations at the ωB97XD/6-31 + G (d,p) level of theory. Electronic properties related to charge transfer between the superalkali and C6H6F6 were obtained through calculations such as NBO charge analysis and frontier molecular orbitals (FMO). The electronic properties are rationalized by the density of states analysis, and in this paper, using the two-energy level model to analyzed the factors that affect the first hyperpolarizability. The frequency-dependent hyperpolarisation coefficients are analyzed to understand the dynamic NLO response. To obtain the NLO response of these new complexes experimentally, the Hyper-Rayleigh scattering (βHRS) coefficients of the complexes were also investigated. The dynamic and static hyperpolarizability properties of these complexes show good NLO response. It is also hoped that this work may provide theoretical help for the future synthesis of new efficient NLO materials.

Sensing potential of C6N8 for ammonia (NH3) and nitrogen triflouride (NF3): A DFT study

The detection of toxic gases (NH3 and NF3) in regulating and monitoring air quality in the atmosphere has drawn a lot of attention. Herein, we explored a novel material (C6N8) for the detection of the important but toxic gases (NH3 and NF3). We investigated the interactions of the NH3 and NF3 with C6N8 through DFT at B3LYP, ωB97XD, and non-DFT M06-2X. Counterpoise interaction energy values (Eint. cp.) of NH3@C6N8 and NF3@C6N8 are −0.45 eV and −3.51 eV (for B3LYP), −0.42 eV and 2.11 eV (for ωB97XD) and −0.44 eV and −3.41eV (for M06-2X), respectively. Complexes having the most stable configurations were then subjected to further analyses including frontier molecular orbitals, H-L gap, and conductivity of complexes. An increase in the H-L gap in complexes (NH3@C6N8 and NF3@C6N8) is observed. The conductivity of NH3@C6N8 and NF3@C6N8 decreases as compared to C6N8. A considerable change in dipole moment was seen in C6N8 before and after complex formation. This is because of the shifting of charge between C6N8 and gases (NH3 and NF3). CHELPG and NBO charge analysis were used to evaluate the amount of charge transfer between C6N8 and gases. These analyses demonstrate that NH3 and NF3 withdraw electron density from C6N8. It was found that NH3 tends to be physically adsorbed on C6N8 while NF3 adsorbs chemically on C6N8. NCI and QTAIM analyses were performed to investigate the kind of interactions between the surface (C6N8) and gases (NH3 and NF3). Furthermore, the recovery time of NH3@C6N8 and NF3@C6N8 shows that C6N8 can be a better choice for sensing NH3 and NF3 gases.

Unveiling the Potential of B3O3 Nanoflake as Effective Transporter for the Antiviral Drug Favipiravir: Density Functional Theory Analysis.

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.

The conversion mechanism of syngas CO and H2 under Au and Au-CCo-doping catalysts

The relative stability, reaction potential energy surface, NBO charge analysis and kinetic properties of Au, Au-C co-doping catalysts in CO and H2 syngas catalytic reactions were studied by density functional theory calculation. The calculation results indicate that the reaction energy barrier and reaction rate showed a consistent pattern of change. NBO charge analysis indicates the feasibility of the catalytic reaction of syngas. We also calculated the rate constant which indicates that the rate constant has a positive temperature dependence. Our calculations show that the reaction is an exothermic reaction catalyzed by Au and Au-C co-doping.

Combined FTIR/Raman spectroscopic studies and ab initio electronic structure calculations of Dithiothreitol

A total of seven minimum energy geometries were obtained on exploring the conformational landscape of dithiothreitol (DTT) by varying the prominent dihedral angles in the molecule through a relaxed scan with a step size of 5° at B3LYP/cc-pVTZ with further geometry optimization at CCSD/cc-pVDZ level of theory. Single point energies were calculated for all the conformers at CCSD(T)/CBS limit with cc-pVNZ (N = T, Q) level of theory and revealed the similar energy pattern. The two conformers, namely G′TG′1 and G′TT, were found iso-energic even though they differed in their structure significantly and were of the lowest energy compared to others. Energies corresponding to the cyclic as well as other configurational counterpart of the global minimum were found much higher in energy compared to the global minimum structure. Intramolecular sulfur centered hydrogen bond was seen to stabilize the global minimum structure of DTT as revealed by AIM, NBO, FMO and ESP charge analysis. Computed NMR of DTT matched well with the experimental data gleaned from the literature. Vibrational spectra (Raman and IR) were measured and compared with computed normal modes of DTT, which were found in good agreement

Giant NLO response and ultraviolet transparency of superalakalis decorated C6O6Li6 complexes; a DFT perspective

Materials having nonlinear optical (NLO) properties are the demand of optics and optoelectronics fields because of their widespread applications. Keeping in view the applications of NLO materials, some new superalkalis doped C6O6Li6 complexes are introduced in this study having remarkable NLO response. Thermodynamic stability of nonlinear optical materials (NLO) is prime requirement of experimentalists for practical applications. All the considered complexes have high thermodynamic stability. Furthermore, these superalkali doped complexes reveal fabulous electronic properties. Superalkalis shift their outer shell electrons towards the C6O6Li6 nanocluster, which act as diffuse excess electrons. The HOMO-LUMO gaps (H-L Egap) of superalkali doped complexes are effectively reduced due to shifting of electrons that reveals their conducting properties. NBO charge analysis confirmed electron charge transfer from superalkalis to C6O6Li6 surface. Linear and NLO properties of these complexes are estimated from first order polarizability (α o) and hyperpolarizability (β o) parameters. Among all complexes, C6O6Li6.K3O has the highest first hyperpolarizability (β o = 6.02 × 105 au). TD-DFT analysis confirmed the ultraviolet transparency of doped complexes. Two level model is used to rationalize the trend of first hyperpolarizability and the internal factors responsible for the enhancement of NLO response.

A DFT study on effective detection of ClCN gas by functionalized, decorated, and doped nanocone strategies.

Density Functional Theory (DFT) was employed to investigate the interaction between cyanogen chloride (ClCN) and the surface of a carbon nanocone (CNC). The findings of this research revealed that pristine CNC is not an ideal material to detect ClCN gas due to its minimal alterations in electronic properties. In order to enhance the properties of carbon nanocones, multiple methods were implemented. These included functionalizing the nanocones with pyridinol (Pyr) and pyridinol oxide (PyrO) as well as decorating them with metals such as boron (B), aluminium (Al) and gallium (Ga). Additionally, the nanocones were also doped with the same third-group metal (B, Al and Ga). The simulation results indicated that doping it with aluminium and gallium atoms yielded promising results. After a comprehensive optimization process, two stable configurations were obtained between the ClCN gas and the CNC-Al, and CNC-Ga structures (configurations S21, and S22) with E ads values of -29.11, and -23.70 kcal mol-1 respectively, using M06-2X/6-311G(d) level. The adsorption of ClCN on CNC-Al and CNC-Ga surfaces leads to a marked alteration in the electrical properties of these structures. Calculations reveal that the energy gap between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) levels (E g) of these configurations increased in the range of 9.03% and 12.54%, respectively, thereby giving off a chemical signal. An analysis conducted by the NCI confirms that there is a strong interaction between ClCN and Al and Ga atoms in CNC-Al and CNC-Ga structures, which is represented by the red color in the RDG isosurfaces. Additionally, the NBO charge analysis reveals that significant charge transfer is present in S21 and S22 configurations (190 and 191 |me|, respectively). These findings suggest that the adsorption of ClCN on these surfaces impacts the electron-hole interaction, which subsequently alters the electrical properties of the structures. Based on the DFT results, the CNC-Al and CNC-Ga structures, which have been doped with aluminium and gallium atoms, respectively, have the potential to serve as good candidates for detecting ClCN gas. Among these two structures, the CNC-Ga structure emerged as the most desirable one for this purpose.

Adsorption, sensing and catalytic properties of the pristine C24N24 nanocage to small gas molecules: A DFT-D3 investigation

Adsorption of small gases (H2, N2, O2, CO, NO, CO2, N2O, NO2, H2S, H2O, SO2, NH3, CH4, C2H4, and C2H2) on the C24N24 (noted by CNNC) was studied using the B3LYP-D3/6-31G(d,p) method. Adsorption energies and thermodynamics of all the studied gases adsorbed onto the CNNC and NBO charge analysis of their adsorption structures were obtained. Adsorption ability of the CNNC on gases was in order: H2O (ΔEads = −25.06 kcal/mol) > SO2 (ΔEads = −11.84 kcal/mol) > NH3 > C2H2 > H2S > N2O > CO2 > NO2 > O2 > NO > C2H4 > CH4 > SO2 > CO > H2 > N2. The high adsorption strength The CNNC was suggested to be a storage material for all studied gases and a potential to be a sensing material for NO. On the CNNC surface, co-adsorption of H2O and SO2 conversion to H2CO3 assumed as Langmuir-Hinshelwood mechanism and co-adsorption of H2O and CO2 co-adsorbed on the CNNC surface was assumed as Langmuir-Rideal mechanism were found. The H2O physisorption over C–N bond of the CNNC to form dissociative chemisorption on C–N bond via transition-state barrier was found.

NLO properties and electride characteristics of superalkalis doped all-cis-1,2,3,4,5,6-hexafluorocyclohexane complexes

The designing and synthesis of efficient NLO materials is the demand of the century because of their importance in the development of photo-electronic devices. Herein, we studied the geometric, electronic, and nonlinear properties of superalkalis doped all-cis-1,2,3,4,5,6-hexafluorocyclohexane, Janus type complexes. These complexes have an unprecedented involvement of respective superalkalis as source of excess electrons, which resulted in the enhancement of nonlinear optical properties and electride characteristics. The interaction energies (−13.57 to −16.54 kcal mol−1) indicated the physisorption of superalkalis on C6H6F6. NBO charge analysis is used to predict the charge transfer during the complexation. The highest NLO response (1.68 ×106 au) is observed for Na2F@C6F6H6 complex. The enhancement in second hyperpolarizability (γo) values is seen at various frequencies. Further, to obtain NLO response from an experimental point of view, hyper Rayleigh scattering (βHRS) is also investigated. These complexes, in addition to being a new entry into excess electron compounds, will pave the way for the designing and synthesis of additional NLO materials. The remarkable static first hyperpolarizability (βo) and second hyperpolarizability (γo) responses make them ideal for future NLO materials.

Computational study of Pd–Cd bimetallic crystals: Spectroscopic properties, hirshfeld surface analysis, non-covalent interaction, and sensor activity

In this current study, we have studied Pd-Cd crystals by using theoretical simulations to investigate their structural properties and sensor activities. The intermolecular interactions in all proposed crystals were analyzed by considering the intermolecular contacts using Hirshfeld surface methods. Density functional theory (DFT) and time depended density functional theory (TD-DFT) calculations were used to predict the desired crystal structures and their electronic and spectroscopic properties. Mulliken and NBO charge analysis was used to predict/explore the charge transfer and distribution. Additionally, molecular docking studies were used to investigate the drugability of hypothesized crystals against PDB file 6JKV.

Hazardous molecules and VOCs sensing properties of Ti functionalized benzene: An ab initio study

Adsorption of volatile organic compounds (VOCs) viz. HCHO, CH4, CHF3 and CH3OH and hazardous gas molecules (NH3, HCN and Cl2) on Titanium-benzene (BTi) complex is investigated by first principle calculations at MP2/6–311 + +G* * level of theory. Interaction between the molecules and BTi complex is analysed with the help of change in structural parameters, vibrational frequencies, density of state plot and NBO charge analysis. The change in HOMO-LUMO gap and electron density state confirms the adsorption of hazardous gas molecules/VOCs on BTi complex. VOCs as well as hazardous gas molecules are chemisorbed on the BTi complex with adsorption energy in the range of 0.5–3.4 eV. ADMP-MD simulations performed at 300 K and 500 K have shown that all the molecules remain adsorbed on BTi complex during the simulations at 300 K as well as 500 K. Ab initio calculations as well as ADMP-MD simulations show that BTi complex shows excellent VOCs and hazardous gas molecule adsorption properties not only at ambient conditions but also for a wide range of temperature and pressure. The BTi complex can be used to design the hazardous gas molecule and VOCs sensor for different temperature and pressure.

Static, dynamic nonlinear optical (NLO) response and electride characteristics of superalkalis doped star like C6S6Li6

In search of excellent nonlinear optical (NLO) materials, new type of M3O@C6S6Li6 (M = K, Na, Li) electrides are set forth herein. The geometric, electronic and nonlinear optical properties of these electrides are evaluated by using density functional theory calculations. All the considered complexes have interaction energies in the range of -42.86 to -45.56 kcal/mol that validate their thermodynamically stability. The NBO charge analysis is performed to confirm the charge transfer between M3O and C6S6Li6. The highest amount of electronic charge transfer (0.92 |e|) is seen in K3O@C6S6Li6 electride. The frontier molecular orbitals (FMOs) and density of states (DoS) analyses are implemented to further rationalize the electronic properties. The remarkable polarizability (αo) and static first hyperpolarizability (βo) observed for these complexes validate their excellent nonlinear optical response. The highest βo (2.98×105 au) is obtained for Li3O@C6S6Li6 electride. The frequency-dependent first and second hyperpolarizability coefficients along with dipole dependent hyperpolarizability are also analyzed to get insight of NLO response under variational frequencies. Furthermore, the Hyper-Rayleigh Scattering coefficient (βHRS) of these complexes is investigated to provide information required for experimental point of view of NLO response. This study will contribute towards the development of more stable superalkalis doped electrides having pronounced NLO response.

Superalkali-based alkalides Li3O@[12-crown-4]M (where M= Li, Na, and K) with remarkable static and dynamic NLO properties; A DFT study

Exploring new nonlinear optical materials with excess electron character is extremely important for promoting the application of excess electron compounds in nonlinear optics. Herein, by using density functional theory (DFT) computations, new superalkali-based alkalides Li3O@[12-crown-4]M− are designed as excess electron compounds. QTAIM studies suggest that the complexant interacts with alkali and superalkali clusters through non-covalent interactions. These complexes are thermodynamically stable and their interaction energies range from −33.40 ∼ −44.23 kcal mol-1. The alkalide nature of these compounds is guaranteed by their HOMOs values and NBO charge analysis. Being excess electron compounds, these alkalides shows potential electronic properties. Their HOMO-LUMO gaps ranging from 0.17–0.27 eV. With excellent properties, these complexes show remarkable total hyperpolarizability (βo) response (9.30×104–5.26×106au). Interestingly, the hyperpolarizability response is dependent on the size of alkali metals. The βvec values are quite comparable to total hyperpolarizability at the same level of theory. Furthermore, the hyperpolarizability calculated through two-level model (βtl) values show a trend similar to hyperpolarizability. Additionally, the dynamic hyperpolarizability response for EOPE effects is much pronounced at the dispersion frequency of 532 nm. The second hyperpolarizability response for the dc-Kerr constant is increased up to 2.75 × 1012 au which is much higher than those of previously reported alkalides. Strikingly, the frequency-dependent NLO response shows dependence on alkalide character rather than the size of alkali metal (M). Moreover, the βHRS value is recorded up to 2.16 × 106 au. The significant dipolar contribution to hyperpolarizabilities Φβ(J = 1) are observed for these complexes.

Crystal growth, spectroscopic and theoretical investigation of nonlinear optical 2‑bromo-4-nitroaniline single crystals for NLO and optoelectronic applications

The non-centrosymmetric space group, organic NLO single crystal of 2‑bromo-4-nitroaniline (2B4NA) was prosperously developed by slow evaporation method at 40 °C. Grown 2B4NA was orthorhombic structure with Pna21 space group was recognised by single crystal XRD analysis. An intermolecular contact of 2B4NA was visually analysed by Hirshfeld surface analysis. Active functional groups were confirmed by vibrational FT-IR, FT-Raman spectral analysis. An electron delocalization, hydrogen bond interactions and charge transfer during the chemical reactions of 2B4NA molecule were theoretically studied by NBO and Natural population charge analysis. Electronic transition and optical property were evaluated by UV-Visible spectral analysis and the theoretical spectrum was computed by TD-DFT level with CAM B3LYP approach. HOMO-LUMO and MESP analysis was visualised the chemical reactivity of the molecule. Thermal TG/DTA and mechanical micro hardness analyses were revealed the thermal and mechanical properties of the 2B4NA crystal. Laser beam irradiated LDT analysis was expressed the laser utility limitation of the 2B4NA crystal. The NLO second harmonic generation efficiency was tested by Kurtz Perry powder method.

Zintl based superatom P7M2 (M=Li, Na, K & Be, Mg, Ca) clusters with excellent second and third-order nonlinear optical response

We report geometric, electronic, and NLO properties of designed zintl superatom P7M2 (M = Li, Na, K & Be, Mg, Ca) clusters in which zintl core P7 is substituted with alkali and alkaline earth metals. The studied superatom clusters show excellent thermal and electronic stabilities and their binding energies pe atom range from −21.54 to −95.93 kcal mol−1. The NBO charge analysis reveals excellent charge separation within the clusters, where the charge is transferred from metals to phosphorus atoms. Furthermore, HOMO-LUMO gaps are significantly reduced which illustrates better electronic properties. The calculated first static hyperpolarizability (βo) and second hyperpolarizability (γo) values are up to 282176 × 10−33 and 30869568 × 10−40 esu, respectively. The variational trend and controlling factors for hyperpolarizability (βo) are also estimated by the two-level model study and the values nicely correlate with each other. The highest βtl value of 185423 × 10−33 esu is obtained for P7Mg2 cluster. The obtained significant NLO response for P7Mg2 and P7Ca2 superatom clusters may be attributed to excess electron character. Moreover, to investigate the nonlinearity from the experimental point of view, we carried out hyper Rayleigh scattering (βHRS) measurement where the highest value of 81340.0 × 10−33 esu, is observed for the P7Ca2 superatom cluster. The excellent NLO responses of these zintl superatoms will pave path for further design and synthesis of even better NLO materials.

First-principles study of the adsorption of chlormethine anticancer drug on C24, B12N12 and B12C6N6 nanocages

The chlormethine (CM) drug adsorption on C24, B12C6N6 and B12N12 nanocages has been investigated by using density functional theory at B3LYP/6-31G(d,p) method. Also, the adsorption energy (EAd) investigation of the CM adsorbed complexes has been done by using wB97XD functional to understand the non-local dispersion interactions. Our study reveals that C24 and B12C6N6 nanocages are unfavorable (very low value of EAd) for CM drug adsorption but B12N12 is a promising adsorbent for this drug as EAd of CM/B12N12 complex is −101.70 kJ/mol (−84.77 BSSE corrected) at B3LYP method and −139.70 kJ/mol (−123.43 BSSE corrected) at wB97XD method. NBO and Mulliken charge analysis predicts that large charge transfer occurs from CM to B12N12 about 0.324|e| and 0.259|e| respectively. Also, the spontaneous and favorable interaction between CM drug and B12N12 nanocage is also confirmed by the investigation of solvation Gibbs free energy and quantum theory of atoms in molecules analysis.

Silver cluster (Ag6) decorated coronene as non-enzymatic sensor for glucose and H2O2

Silver-graphene quantum dots are promising electrochemical sensors due to their unique electronic properties. Herein, we report the comprehensive DFT study to explore the electronic properties of silver cluster (Ag6) decorated coronene as model for silver graphene quantum dots. The current study aims to investigate the sensing ability of silver-coronene complex for non-enzymatic electrochemical detection of glucose & H2O2. The stability of the complexes of analytes with silver decorated coronene is supported by their greater interaction energies (−36.7 to −44.9 kcal mol−1). NBO charge analysis and charge decomposition analysis (CDA) reveal donor-acceptor charge transfer interactions in the complexes. Frontier molecular orbital analysis illustrates that charge is transferred from analytes to silver decorated coronene during excitation from HOMO to LUMO. The Uv–visible results show that λmax is red shifted during interactions of analytes with silver decorated coronene. The NCI analysis illustrates the strong non-covalent (M … O) and unusual M … H–O interactions in the complexes. The precedent sensing performance of Ag6-coronene might be attributed to the synergistic effect of both silver clusters and coronene in the composite. The evaluated results validate the excellent sensing ability of silver-graphene quantum dots for the detection of glucose & H2O2. The outcome of the current study and its prospects will open the avenue for the rational development of smart sensors.

Permeation of second row neutral elements through Al12P12 and B12P12 nanocages; a first-principles study

Both exohedral and endohedral complexes of second row elements doped X12Y12 (X = B, Al and Y = P) nano-cages are evaluated for thermodynamic stabilities, electronic properties and kinetic barriers. Interaction energies are calculated to deeply perceive the stability of these complexes. Further, interconversion of exohedral and endohedral complexes is explored through an unprecedented approach, where 2nd row elements translate into nano-cages through boundary crossing. Subsequently, the kinetic barriers for encapsulation and decapsulation are also investigated through PES scanning of all elements by passing through hexagon of nano-cages. Systematic investigations revealed that due to larger diameter, AlP nanocage exhibits low encapsulation barriers in comparison to BP nano-cage. Such as; the encapsulation barrier of F@AlP (7.57 kcal mol−1) is lower than that of F@BP (129.78 kcal mol−1). Moreover, distortion of nano-cages due to translation of elements is also estimated by distortion energies. Large distortion energies of 113.81/118.39 kcal mol−1 are noticed for exo-B@AlP/exo-C@BP complexes. In addition, the electronic properties for all the complexes are probed and depicted that the endohedral doping have remarkable influence on the electronic properties of the nanocage in comparison to exohedral doping. NBO charge analysis shows that Be metal delivers charges of 0.08 |e|/0.03 |e| to the AlP/BP nanocage, causing the later more electron rich. Contrary to Be, all other doped atoms show negative charges.