Corrected Binding Energies Research Articles

A first-principles adsorption study of functionalized carbon, boron nitride, silicon carbon nanotubes with ifosfamide as vehicles for drug delivery: Thermal analysis

We investigated the adsorption of ifosfamide (IFS) on the outer surface of zigzag (10, 0) carbon nanotubes (CNT), boron nitride nanotubes (BNNT), and silicon carbon nanotubes (SiCNT), using density functional theory (DFT) calculations at the PBE-D3 level in a water solvent phase. Based on zero-point corrected binding energies (Ebin), IFS exhibits chemisorption through its O-head and Cl-head on CNT (−1.05 eV) compared to BNNT (−0.93 eV), characterized by covalent interaction. In contrast, IFS undergoes physisorption via its O-head on SiCNT with binding energy of −0.68 eV as the most stable model this interaction is driven by electrostatic forces. The formation of complexes between the drug and nanotubes is influenced by charge transfer dynamics. Our thermodynamic analysis demonstrates the Gibbs free energy (ΔG) and enthalpy energy (ΔH) for all models are exothermic and spontaneous. The observed decrease in binding energy for BNNT and CNT correlates with changes in their energy gap, dipole moment, and charge transfer upon IFS adsorption. Notably, SiCNT exhibits a different response with a significant energy gap change leading to an increase in dipole moment and charge transfer. These findings suggest that these nanotubes demonstrate promising sensitivity to the presence of IFS and could be explored as potential drug delivery systems for this drug.

Electrical contact property and control effects for stable T(H)-TaS2/C3B metal-semiconductor heterojunctions.

Metal-semiconductor heterojunctions are the basis for developing new electronic devices. Here, T(H)-TaS2/C3B metal-semiconductor heterostructures are constructed by different phase T- and H-TaS2 monolayers combined with the C3B monolayer. The calculated corrected binding energies, phonon band structures, elastic constants, and molecular dynamics simulations indicated that both heterojunctions are highly stable, meaning that T(H)-TaS2/C3B heterojunctions possibly exist in experiments. The electronic property calculations showed that the intrinsic T(H)-TaS2/C3B heterojunction is an n(p)-type Schottky contact with a low Schottky barrier height (SBH), which is very important for the design of high-performance field-effect transistors. The electronic properties of the T(H)-TaS2/C3B heterojunctions can be controlled by varying the vertical strain and external electric field; however, the strain only resulted in a small change in the heterojunction SBH. Nevertheless, under external electrical field control, the T-TaS2/C3B heterojunction could manage a transition from an n-type Schottky contact to an n-type Ohmic contact and the H-TaS2/C3B heterojunction could be altered from a p-type Schottky contact to a p-type Ohmic contact. These findings provide theoretical insights into the electronic and electrical contact properties of the T(H)-TaS2/C3B heterojunction, which could be beneficial for developing n-type MOS and p-type MOS transistors.

Core-Level 2s and 2p Binding Energies of Third-Period Elements (P, S, and Cl) Calculated by Hartree-Fock and Kohn-Sham ΔSCF Theory.

In the present study, we investigate the use of the ΔSCF method and Slater's transition state (STS) theory to calculate the binding energies of the 2s and 2p electrons of third-period elements (P, S, and Cl). Both the Hartree-Fock (HF) and Kohn-Sham (KS) approximations are examined. The STS approximation performs well in reproducing the ΔSCF values. However, for the ΔSCF method itself, while the binding energy of the 2p electrons is accurately predicted, the results for 2s are fairly sensitive to the functional, exhibiting significant variations due to self-interaction errors (SIE). Nonetheless, the variations in chemical shifts between different species remain relatively small, and the values agree with experiments due to the cancellation of SIE. A notable observation is that the chemical shifts of the 2s and 2p electrons are similar, indicating a perturbation caused by the valence electrons. The error in the absolute binding energy of KS ΔSCF against the experiment is nearly constant for the same element in different molecules, and it depends largely on the functional owing to SIE. A shifting scheme previously developed can be employed to reproduce the experimental 2s and 2p binding energies, with dependence on the functional and atom but not on the molecule even for 2s KS ΔSCF binding energies. Upon obtaining the corrected binding energies, we find that the gap between 2s and 2p binding energy is nearly independent of chemical environment for a given element: 57.5, 63.9, and 70.9 eV for the elements P, S, and Cl, respectively.

Halide‐Triel Bonds between R3SiX (X=F, Cl and Br) and TrY3 (Tr=Al, B and Ga)

AbstractHalide‐triel bonds between halosilane donors and alane/borane/gallane acceptors are investigated considering 24 model complexes using quantum chemical calculations. Nature and strength of Si−X….Tr interactions (X=F, Cl, Br and Tr=Al, B, Ga) binding these complexes has been studied using Electrostatic Potential (ESP), Quantum Theory of Atoms in Molecules (QTAIM), Natural Bond Orbital (NBO), and Energy Decomposition Analysis (EDA) techniques. Basis Set Superposition Error (BSSE) corrected binding energy of the complexes ranges from −3.19 to −29.40 kcal mol−1. QTAIM parameters Laplacian and the total electron density at the Bond Critical Points (BCPs) indicate that the halide‐triel bonds studied here are largely electrostatic in nature (closed‐shell interactions); this has also been revealed through ESP analysis and EDA scheme. In addition, role of charge transfer in these halide‐triel bonds has also been established through NBO analysis. Two charge transfer orbital interactions are responsible for the primary interaction Si−X….Tr: and σ(Si−X) . EDA analysis identifies electrostatic term as the biggest contributor towards the binding of the complexes followed by the polarisation and dispersion terms in most of the complexes. Results of this study have relevance in the Si−F bond activation methodology in organic synthesis.

Critical method evaluation refutes the Ar 2p signal of implanted Ar for referencing X-ray photoelectron spectra

Correct binding energy (BE) spectra referencing of insulating samples remains the major challenge in modern XPS analyses. Ar 2p signal of implanted Ar is sometimes used for this purpose. The method relies upon the assumption that chemically inert species such as noble gas atoms would be ideally suited as other factors affecting core level peak positions (such as chemical bonding) can be excluded. Here, we present a systematic study on the Ar 2p referencing method applied to a wide range of thin film sample materials of metals, nitrides, carbides, and borides. All specimens exhibit a well-defined Fermi edge, which serves as an independent internal reference for Ar 2p spectra of in-situ implanted Ar. Ar 2p3/2 binding energy is shown to vary by as much as 5.1 eV between samples. This is more than typical chemical shifts of interest, which obviously disqualifies Ar 2p referencing. The BE of the Ar 2p peaks shows a strong correlation to the number of valence electrons available for screening, implying that the polarization energy has a major role for the observed large spread of Ar 2p3/2 BE values. In several cases of single-phase films, an additional Ar 2p doublet is observed with the Ar 2p3/2 BE referenced to the vacuum level higher than the gas phase value of 248.6 eV, which is tentatively assigned to the formation of Ar-N and Ar-C complexes stabilized by Van der Waals forces. Ar implantation into two-phase samples, exemplified here by phase-segregated NiCrC/a-C:H and nanocomposite c-TiN/SiNx thin films, leads to complex Ar 2p spectra, which further demonstrates unreliability of the referencing method. The firm conclusion of the study is that the Ar 2p3/2 peak from implanted Ar is not a remedy for the charge referencing problem.

A unified secondary electron cut-off presentation and common mistakes in photoelectron spectroscopy

Photoelectron spectroscopy is a powerful surface analysis technique that can differentiate different bonding environments and directly determine the absolute work function of a sample. Despite its ever-easier accessibility—or perhaps precisely because of it—some common mistakes or bad habits are often found in the literature when it comes to the evaluation or presentation of photoelectron spectroscopy data. Here we address some of these issues and give suggestions for best practice, i.e., a proper presentation of the secondary electron cut-off used for work function determination, correct binding energy referencing and some tips for appropriate peak fitting, as well as valuable literature references to more detailed tutorials. Finally, we present a concise step-by-step guide on how to conduct a complete x-ray photoelectron spectroscopy analysis of an unknown sample.

Self‐Trapped Exciton States in Metal Halide Perovskites van der Waals Heterostructures

Self‐trapped excitons (STEs), proved to be the major source of white‐light emission in 2D metal halide perovskites (MHPs) van der Waals (vdW) heterostructures, have aroused intense interest in photovoltaic and photoelectric applications. Nevertheless, the intrinsic mechanisms of STEs in these vdW heterostructures are still ambiguous. Herein, the binding energy correction of a STE stemming from the exciton–phonon coupling in MHPs vdW heterostructures based on the Pollmann–Büttner model is studied. It is found that there are two types of STEs with and . The corresponding nuclear coordinate diagrams are given to explain the differences between them and why the STEs with are hard to be observed in experiments. The phase transition between two types of STEs can be achieved by regulating the structural parameters, such as the vertical distance between the encapsulation layers, the position of the monolayer MHP in the heterostructure as well as replacing the encapsulation materials. The theoretical results provide important insights into the analysis and modulation of STEs in 2D vdW heterostructures.

Non-covalent bonds in group 1 and group 2 elements: the 'alkalene bond'.

The non-covalent bonds formed by group 1 and group 2 elements were systematically analysed by ab initio calculations at the MP2/aug-cc-pVDZ (for Ca, 6-311++G(2df,p) basis sets were used) level of theory to classify the weak bonds, followed by Atoms in Molecules (AIM) analysis of the ab initio wave functions. It has been established that there is a strong correlation between the electron density at the non-covalent bond critical point (BCP) and the binding energy for each homogeneous sample of complexes. The slopes of the electron density versus binding energy plot have been obtained for group 1 and group 2 donor molecules (Dn-X⋯A, for X = H, D = F/-OH/-SH, for X = Li, Na, D = F/Cl/Br and for X = Be, Mg, and Ca, D = F/Cl/H) with a set of acceptor molecules (A), which includes H2O, NH3, H2S, PH3, HCHO, C2H4, HCN, CO, CH3OH and CH3OCH3. The bonds formed by group 1 (except H-bonds) and group 2 belong to a high slope dominated by electrostatics, with several similarities, leading us to propose a common name, 'alkalene bond', for non-covalent bonding in alkali and alkaline earth metals.

Identifying chemical and physical changes in wide-gap semiconductors using real-time and near ambient-pressure XPS.

Photoelectron spectroscopy is a powerful characterisation tool for semiconductor surfaces and interfaces, providing in principle a correlation between the electronic band structure and surface chemistry along with quantitative parameters such as the electron affinity, interface potential, band bending and band offsets. However, measurements are often limited to ultrahigh vacuum and only the top few atomic layers are probed. The technique is seldom applied as an in situ probe of surface processing; information is usually provided before and after processing in a separate environment, leading to a reduction in reproducibility. Advances in instrumentation, in particular electron detection has enabled these limitations to be addressed, for example allowing measurement at near-ambient pressures and the in situ, real-time monitoring of surface processing and interface formation. A further limitation is the influence of the measurement method through irreversible chemical effects such as radiation damage during X-ray exposure and reversible physical effects such as the charging of low conductivity materials. For wide-gap semiconductors such as oxides and carbon-based materials, these effects can be compounded and severe. Here we show how real-time and near-ambient pressure photoelectron spectroscopy can be applied to identify and quantify these effects, using a gold alloy, gallium oxide and semiconducting diamond as examples. A small binding energy change due to thermal expansion is followed in real-time for the alloy while the two semiconductors show larger temperature-induced changes in binding energy that, although superficially similar, are identified as having different and multiple origins, related to surface oxygen bonding, surface band-bending and a room-temperature surface photovoltage. The latter affects the p-type diamond at temperatures up to 400 °C when exposed to X-ray, UV and synchrotron radiation and under UHV and 1 mbar of O2. Real-time monitoring and near-ambient pressure measurement with different excitation sources has been used to identify the mechanisms behind the observed changes in spectral parameters that are different for each of the three materials. Corrected binding energy values aid the completion of the energy band diagrams for these wide-gap semiconductors and provide protocols for surface processing to engineer key surface and interface parameters.

Novel microporous B6N6 covalent organic framework (COF) as an electrochemical sensor for the ultra-selective detection of nitroaniline isomers; a DFT outcome

The density functional theory (DFT) simulations are performed to study the sensitivity and selectivity of a novel (star shape) boron nitride two-dimensional covalent organic framework (B6N6) towards adsorption of toxic nitroaniline isomers. The binding energies of nitroaniline isomers onto the B6N6 material have been evaluated with hybrid B3LYP functional along with third order Grimme dispersion (D3) method in order to accurately account for dispersion effects. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) illustrate that weak van der Waals forces are the main contributor in stabilizing the reported complexes. The BSSE corrected binding energies of oNA, mNA and pNA on B6N6 are -15.42, -14.73 and -14.34 kcal/mol, respectively. These results reveal that the sensitivity and selectivity of B6N6 decreases in the order of oNA > mNA > pNA. The effect of aromaticity of nitro-aniline isomers in stabilizing the complexes is studied through the ring critical point (RCP) based on Bader atoms in molecule analysis. The sensitivity of B6N6 for nitroaniline isomers is further justified by the electronic properties. For example, the density of states (DOS) reveal that the new occupied energies states appear between original HOMO and LUMO orbitals of pristine B6N6 upon complexation with nitroaniline isomers. The newly generated occupied orbitals are closer to the Fermi energy level which increase the conductivity of B6N6, thus the significant amount of NBO charge transfer is noticed. The amounts of charge transfer in oNA@B6N6, mNA@B6N6 and pNA@B6N6complexes are 0.05, 0.09 and 0.05 e−, respectively. The percentage contribution of orbitals in charge transfer is estimated by the orbital composition analysis. Finally, the effect of increasing concentration of nitroaniline molecules on the sensing properties of B6N6 is also studied, which shows that the binding energies are less negative per molecule by increasing the number of nitroaniline units. The findings of this study reveal that the B6N6 star like COF material shows excellent sensing abilities for the toxic molecules. In summary, B6N6 material is a valuable addition with ultrahigh sensitivity as well as selectivity for future electrochemical sensor devices.

XPS guide: Charge neutralization and binding energy referencing for insulating samples

This guide deals with methods to control surface charging during XPS analysis of insulating samples and approaches to extracting useful binding energy information. The guide summarizes the causes of surface charging, how to recognize when it occurs, approaches to minimize charge buildup, and methods used to adjust or correct XPS photoelectron binding energies when charge control systems are used. There are multiple ways to control surface charge buildup during XPS measurements, and examples of systems on advanced XPS instruments are described. There is no single, simple, and foolproof way to extract binding energies on insulating material, but advantages and limitations of several approaches are described. Because of the variety of approaches and limitations of each, it is critical for researchers to accurately describe the procedures that have been applied in research reports and publications.

Proton Transfer in Phosphoric Acid-Based Protic Ionic Liquids: Effects of the Base.

Electronic structure calculations were performed to understand highly decoupled conductivities recently reported in protic ionic liquids (PILs). To develop a molecular-level understanding of the mechanisms of proton conductivity in PILs, minimum-energy structures of trimethylamine, imidazole, lidocaine, and creatinine (CRT) with the addition of one to three phosphoric acid (PA) molecules were determined at the B3LYP/6-311G** level of theory with the inclusion of an implicit solvation model (SMD with ε = 61). The proton affinity of the bases and zero-point energy corrected binding energies were computed at a similar level of theory. Proton dissociation from PA occurs in all systems, resulting in the formation of ion pairs due to the relatively strong basicity of the bases (proton acceptors) and the effect of the high dielectric constant solvent in stabilizing the charge separation. The second and third PA molecules preferentially form "ring-like" hydrogen bonds with one another instead of forming hydrogen bonds at the donor and acceptor sites of the bases. Potential energy scans reveal that the bases with stronger proton affinity exert greater influence on the energetics of proton transfer between the individual PA molecules. However, the effects are minimal when shifted into a single-well from a double-well potential. Barrierless proton transfer was observed to occur in the CRT system with several PA molecules present, implying that the CRT may be a promising PA-based PIL.

Prediction of an exotic state around 4240 MeV with JPC=1−+ as the C -parity partner of Y(4260) in a molecular picture

The possibility of the Y(4260) being the molecular state of $D\bar D_1(2420)+\mathrm{c.c.}$ is investigated in the one boson exchange model. It turns out that the potential of $J^{PC}=1^{--}$ state formed by $D\bar D_1(2420)+\mathrm{c.c.}$ is attractive and strong enough to bind them together when the momentum cutoff $\Lambda \gtrsim 1.4$ GeV. To produce the Y(4260) with correct binding energy, we need $\Lambda\approx 2.1$ GeV. Besides, $D\bar D_1(2420)+\mathrm{c.c.}$ can also form a state with exotic quantum numbers, $J^{PC}=1^{-+}$, and its potential similar with that of the $J^{PC}=1^{--}$ state. Therefore, an exotic state with mass around 4240 MeV (called $\eta_{c1}(4240)$) is predicted to exist. Our estimation of the mass of the $J^{PC}=1^{-+}$ state in charmonium region is in agreement with those predicted by the chiral quark model and the lattice QCD. The possible decay modes and their relative widths are estimated and the results suggest that this exotic state can be searched for in $\eta\eta_c$ and $\eta\chi_{c1}$ channels.

Intramolecular hydrogen bonding, π-π stacking interactions, and substituent effects of 8-hydroxyquinoline derivative supermolecular structures: a theoretical study

Quantum chemical calculations have been performed to gauge intramolecular hydrogen bonding and π-π stacking interactions of 8-hydroxyquinoline (8-HQ) derivatives (substituents X = OH, CH3, H, F, Cl, CF3, CN, NO2) supermolecular structures. The effects of substituents on 8-HQ derivatives have also been studied with the M06-2X method and 6-311++G** basis set. The basis set superposition error (BSSE)-corrected binding energies (ΔE), hydrogen bonding distances (rH···N), and intermolecular distance (d┻) were calculated with corresponding Hammett electronic parameters (σ). The topological parameters (ρ, ∇ρ2) and energy of intramolecular hydrogen bonding interaction (EH···N) of these π-π stacking 8-HQ derivatives have been studied by using atoms in molecules (AIM) theory. The electrostatic potential (ESP) analysis has been applied to gain the most negative and the most positive electrostatic potential V(r) values (Vs,min and Vs,max). It can be found that there are good relationships between the Hammett constants and the Vs,min values.

Impact of Size and Electronegativity of Halide Anions on Hydrogen Bonds and Properties of 1-Ethyl-3-methylimidazolium-Based Ionic Liquids.

The effect of the anion size and electronegativity of halide-based anions (Cl-, Br-, I-, and BF4-) on the interionic interaction in 1-ethyl-3-methylimidazolium-based ionic liquids (ILs) C2mim X (X = Cl, Br, I, and BF4) is studied by a combined approach of experiments (Raman, IR, UV-vis spectroscopy) and quantum chemical calculations. The fingerprint region of the Raman spectra of these C2mim X ion-pairs provides evidence of the presence of the conformational isomerism in the alkyl chain of the C2mim+ cation. The Raman and IR bands of the imidazolium C2-H stretch vibration for C2mim X (X = Cl, Br, I, and BF4) were noticeably blue-shifted with the systematic change in size of anions and the electronegativity. The observed blue shift in the C2-H stretch vibration follows the order C2mim BF4 > C2mim I > C2mim Br > C2mim Cl, which essentially indicates the strong hydrogen bonding in the C2mim Cl ion-pair. DFT calculations predict at least four configurations for the cation-anion interaction. On the basis of relative optimized energies and basis-set-superposition-error (BSSE) corrected binding energies for all ion-pair configurations, the most active site for the anion interaction was found at the C2H position of the cation. Besides information about the C2H position, our DFT results give insights into the anion interaction with the ethyl and methyl chain of the cation, which was also confirmed experimentally [ Chem. Commun. 2015 , 51 , 3193 ]. The anion interaction at the C2H site of the cation favors a planar geometry in C2mim X for X = Cl, Br, and I; however, for BF4, the system prefers a nonplanar geometry where the anion is located over the imidazolium ring. TD-DFT results were used to analyze the observed UV-vis absorption spectra in a more adequate way giving insights into the electronic structure of the ILs. Overall, a reasonable correlation between the observed and the DFT-predicted results is established.

Tuning the physicochemical properties of the single-walled boron nitride nanotube by covalent grafting of triazolium-based [MTZ][X1–3] (X1–3 = NTf2−, TfO− and BF4−) ionic liquids in the gas phase and solvent media: A quantum chemical approach

Covalent grafting of boron nitride nanotubes (BNNTs) using ionic liquids can effectively adjust their electronic structures, magnetic properties and solubility, and leads to the development of applications of the boron nitride nanotubes. Because of the localization features of the BNNT π electron system, the empty p orbitals of boron sites can be filled by excess electrons, which encourage covalent bonding with an unpaired electron. In the present work, physicochemical characteristics of the (8,0) zigzag boron nitride nanotubes (BNNTs) functionalized by methyl 1,2,4 triazolium [MTZ] [X1–3] (X1–3=NTf2−, TfO−, and BF4−) based ionic liquids (ILs) were explored at the M06-2X/6–31+G(d,p) level of theory. Three different functionalized-NTs (NTMTZ-X1–3) were found on the potential energy surface. Comparison of the corrected binding energies showed that the stability of the complexes decreases in the order of NTMTZ-X2≈NTMTZ-X1>NTMTZ-X3. From the solvation Gibbs free energies, it was predicted that the solubility in water increases upon surface functionalization of the BNNT. A remarkable reduction in the HOMO-LUMO gap was predicted from 7.30eV in BNNT to 2.91eV in [NTMTZ]+, and 3.18, 3.26 and 4.46eV in NTMTZ−X1–3 complexes, respectively. The density of states (DOS) analysis revealed that the covalent functionalization of BNNT with ILs results in the spin polarization and induces spontaneous magnetization. In addition, the charge transfer values, electron density properties, dipole moment, electrochemical windows (ECW), non-covalent interactions (NCI) index, anodic and cathodic stability were also evaluated. The results also showed that complexes formed from the [BF4]− anion have a wider ECW.

Theoretical Prediction of Size-Dependent Structures and Properties for the Asymmetric Clusters (HBrInN3)n (n = 1–6)

In order to search single-source precursors (SSP) for InN material, the structures, relative stabilities, and electronic properties of small asymmetric clusters (HBrInN3)n (n = 1–6) are systematically investigated at the B3LYP level. The optimized clusters all contain cyclic structures (InNα)n and prefer 3-dimensional configurations for n = 2–6. The uncorrected binding energies (Eb), corrected binding energies (Eb-c) and average corrected binding energies (Eb-c-ave) all reveal that all asymmetric clusters (HBrInN3)n (n = 1–6) can continue to gain energy with the cluster size n increasing. The relative stabilities of clusters (HBrInN3 )n (n= 1–6) are analysed based on the second-order difference of energy (Δ2E) and HOMO–LUMO energy gap (Egap). It is found that the Δ2E exhibits a pronounced even–odd alternation phenomenon with variation of the cluster size n. Compared with monomer HBrInN3, the N–N asymmetric stretching of N3 groups for asymmetric clusters (HBrInN3)n (n = 2–6) shows blue-shifted, however, the N–N symmetric stretching of N3 groups and In–H stretching vibration exhibit red-shifted, respectively. Thermodynamic properties increase linearly with the cluster size n as well as the temperature. The transformations of the clusters (HBrInN3)n (n = 2–6) from the monomer are thermodynamically favorable at 298.2 K judged by Gibbs free energies.

Magneto-optical Transitions of GaAs/AlGaAs Multiple Quantum Wells

Photoluminescence (PL) transitions of an undoped GaAs/Al0.33Ga0.67As multiple quantum well structure composed of four different well widths (3, 5, 7 and 10 nm) were investigated under pulsed magnetic fields to 50 T. At B = 0 T, four corresponding PL peaks were detected, which exhibit PL line broadening for narrow quantum wells (3 and 5 nm) due to the interface roughness. By comparing the PL peak transition energies with the calculated transition energies including the binding energy corrections, the exact quantum well widths can be determined. In the presence of a magnetic field, PL transitions undergo a diamagnetic shift. By fitting the diamagnetic shift, we were able to estimate the dimensionality parameters, diamagnetic coefficient and magnetic-to-Coulomb energy ratio.

DFT Calculations of Structure and Properties of Asymmetric Clusters (HClInN3)n (n = 1–6)

In order to find single-source precursors of InN material, the structures and properties of small asymmetric clusters (HClInN3)n (n = 1–6) are studied by means of the density functional theory. The frameworks of clusters (HClInN3)n (n = 2–6) prefer to be 2n-membered ring with alternating indium and α-nitrogen atoms. The uncorrected binding energies (Eb), corrected binding energies (Eb-c) and average corrected binding energies (Eb-c-ave) all reveal that all of asymmetric clusters (HClInN3)n (n = 1–6) can continue to gain energy upon increasing the cluster size n. The relationship between HOMO–LUMO energy gap (Egap) and cluster size n is discussed. Thermodynamic properties are linearly correlated with the cluster size n as well as with the temperature. According to the calculated Gibbs free energies, the formation of the clusters (HClInN3)n (n = 2–6) from the monomer is thermodynamically favorable below 700 K.

A DFT study of inclusion complexes of substituted calix[n]arenes with dasatinib and lapatinib

Herein, we have presented the results of Density Functional Theory (DFT) based calculations of inclusion complexes of lapatinib and dasatinib with calix[n]arene macrocycles. A total of 48 calix [n]arene complexes were modeled via considering varied ring sizes (n = 4,5,6,8) and upper-rim functionalization viz. SO3H, tert-Butyl, iso-Propyl, COOH, C2H5OH, and C2H5NH2. From the results of multilevel molecular docking, DFT energetics, and reactivity descriptors; it has been demonstrated that dasatinib form optimal complexes with calix 4f, 3f (−35 to −40 kcal/mol). Moreover, for lapatinib, hosts 3f, 4a, 1f, 3d have the capability to generate promising complexes (>35 kcal/mol). Based on counterpoise corrected binding energies (Ebind) and global reactivity descriptors, we anticipate that the proposed complexes can vitally be used as analogous to carrier-mediated-drug-delivery.