1,2,3-triazole and chiral Schiff base hybrids as potential anticancer agents: DFT, molecular docking and ADME studies

A series of novel 1,2,3-triazole and chiral Schiff base hybrids 2-6 were synthesized by Schiff base condensation reaction from pre-prepared parent component of the hybrids (1,2,3-triazole 1) and series of primary chiral amines and their chemical structure were confirmed using NMR and FTIR spectroscopies, and CHN elemental analysis. Compounds 1-6 were evaluated for their anticancer activity against two cancer PC3 (prostate) and A375 (skin) and MRC-5 (healthy) cell lines by Almar Blue assay method. The compounds exhibited significant cytotoxicity against the tested cancer cell lines. Among the tested compounds 3 and 6 showed very good activity for the inhibition of the cancer cell lines and low toxicity for the healthy cell lines. All the compounds exhibited high binding affinity for Androgen receptor modulators (PDB ID: 5t8e) and Human MIA (PDB ID: 1i1j) inhibitors compared to the reference anticancer drug (cisplatin). Structure activity relationships (SARs) of the tested compounds is in good agreement with DFT and molecular docking studies. The compounds exhibited desirable physicochemical properties for drug likeness.

Adsorption and sensor performance of transition metal-decorated zirconium-doped silicon carbide nanotubes for NO2 gas application: a computational insight

Owing to the fact that the detection limit of already existing sensor-devices is below 100% efficiency, the use of 3D nanomaterials as detectors and sensors for various pollutants has attracted interest from researchers in this field. Therefore, the sensing potentials of bare and the impact of Cu-group transition metal (Cu, Ag, Au)-functionalized silicon carbide nanotube (SiCNT) nanostructured surfaces were examined towards the efficient detection of NO2 gas in the atmosphere. All computational calculations were carried out using the density functional theory (DFT) electronic structure method at the B3LYP-D3(BJ)/def2svp level of theory. The mechanistic results showed that the Cu-functionalized silicon carbide nanotube surface possesses the greatest adsorption energies of -3.780 and -2.925 eV, corresponding to the adsorption at the o-site and n-site, respectively. Furthermore, the lowest energy gap of 2.095 eV for the Cu-functionalized surface indicates that adsorption at the o-site is the most stable. The stability of both adsorption sites on the Cu-functionalized surface was attributed to the small ellipticity (ε) values obtained. Sensor mechanisms confirmed that among the surfaces, the Cu-functionalized surface exhibited the best sensing properties, including sensitivity, conductivity, and enhanced adsorption capacity. Hence, the Cu-functionalized SiCNT can be considered a promising choice as a gas sensor material.

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

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

Impact of Polythiophene ((C4H4S)n; n = 3, 5, 7, 9) Units on the Adsorption, Reactivity, and Photodegradation Mechanism of Tetracycline by Ti-Doped Graphene/Boron Nitride (Ti@GP_BN) Nanocomposite Materials: Insights from Computational Study

This study addresses the formidable persistence of tetracycline (TC) in the environment and its adverse impact on soil, water, and microbial ecosystems. To combat this issue, an innovative approach by varying polythiophene ((C4H4S)n; n = 3, 5, 7, 9) units and the subsequent interaction with Ti-doped graphene/boron nitride (Ti@GP_BN) nanocomposites was applied as catalysts for investigating the molecular structure, adsorption, excitation analysis, and photodegradation mechanism of tetracycline within the framework of density functional theory (DFT) at the B3LYP-gd3bj/def2svp method. This study reveals a compelling correlation between the adsorption potential of the nanocomposites and their corresponding excitation behaviors, particularly notable in the fifth and seventh units of the polythiophene configuration. These units exhibit distinct excitation patterns, characterized by energy levels of 1.3406 and 924.81 nm wavelengths for the fifth unit and 1.3391 and 925.88 nm wavelengths for the seventh unit. Through exploring deeper, the examination of the exciton binding energy emerges as a pivotal factor, bolstering the outcomes derived from both UV-vis transition analysis and adsorption exploration. Notably, the calculated exciton binding energies of 0.120 and 0.103 eV for polythiophene units containing 5 and 7 segments, respectively, provide compelling confirmation of our findings. This convergence of data reinforces the integrity of our earlier analyses, enhancing our understanding of the intricate electronic and energetic interplay within these intricate systems. This study sheds light on the promising potential of the polythiophene/Ti-doped graphene/boron nitride nanocomposite as an efficient candidate for TC photodegradation, contributing to the advancement of sustainable environmental remediation strategies. This study was conducted theoretically; hence, experimental studies are needed to authenticate the use of the studied nanocomposites for degrading TC.

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

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

High throughput computations of the effective removal of liquified gases by novel perchlorate hybrid material

The utilization of hybrid materials in separation technology, sorbents, direct air capture (DAC) technology, sensors, adsorbents, and chiral material recognition has increased in the past decade due to the recognized impact of atmospheric pollutants and hazardous industrial gases on climate change. A novel hybrid material, perchlorate hybrid (PClH), has been proposed in this study for the effective sensory detection and trapping of atmospheric pollutants and industrial hazardous gases. The study evaluated the structural properties, adsorption mechanism, electronic sensitivity, and topological analysis of PClH using highly accurate computational methods (M062X-D3BJ/def2-ccpVTZ and DSDPBEP86/def2-ccpVTZ). The computational analysis demonstrated that PClH has considerable adsorption energies and favorable interaction with CO2, NO2, SO2, COCl2, and H2S. PClH is more suitable for detecting liquefiable gases such as COCl2, CO2, and SO2, and can be easily recovered under ambient conditions. Developing such materials can contribute to reducing hazardous gases and pollutants in the atmosphere, leading to a cleaner and safer environment.

First-principle study of Cu-, Ag-, and Au-decorated Si-doped carbon quantum dots (Si@CQD) for CO2 gas sensing efficacies

CONTEXT

Nanosensor materials for the trapping and sensing of CO₂ gas in the ecosystem were investigated herein to elucidate the adsorption, sensibility, selectivity, conductivity, and reactivity of silicon-doped carbon quantum dot (Si@CQD) decorated with Ag, Au, and Cu metals. The gas was studied in two configurations on its O and C sites. When the metal-decorated Si@CQD interacted with the CO₂ gas on the C adsorption site of the gas, there was a decrease in all the interactions with the lowest energy gap of 1.084 eV observed in CO₂_C_Cu_Si@CQD followed by CO₂_C_Au_Si@CQD which recorded a slightly higher energy gap of 1.094 eV, while CO₂_C_Ag_Si@CQD had an energy gap of 2.109 eV. On the O adsorption sites, a decrease was observed in CO₂_O_Au_Si@CQD which had the least energy gap of 1.140 eV, whereas there was a significant increase after adsorption in CO₂_O_Ag_Si@CQD and CO₂_O_Cu_Si@CQD with calculated ∆E values of 2.942 eV and 3.015 eV respectively. The adsorption energy alongside the basis set supposition error (BSSE) estimation reveals that CO₂_C_Au_Si@CQD, CO₂_C_Ag_Si@CQD, and CO₂_C_Cu_Si@CQD were weakly adsorbed, while chemisorption was present in the CO₂_O_Ag_Si@CQD, CO₂_O_Cu_Si@CQD, and CO₂_O_Au_Si@CQD interactions. Indeed, the adsorption of CO₂ on the different metal-decorated quantum dots affects the Fermi level (E_f) and the work function (Φ) of each of the decorated carbon quantum dots owed to their low E_f values and high ∆Φ% which shows that they can be a prospective work function-based sensor material.

METHODS

Electronic structure theory method based on first-principle density functional theory (DFT) computation at the B3LYP-GD3(BJ)/Def2-SVP level of theory was utilized through the use of the Gaussian 16 and GaussView 6.0.16 software packages. Post-processing computational code such as multi-wavefunction was employed for result analysis and visualization.

Metals (Ga, In) decorated fullerenes as nanosensors for the adsorption of 2,2-dichlorovinyldimethylphosphate agrochemical based pollutant

Owing to the fact that the use of 2,2-dichlorovinyldimethylphosphate (DDVP) as an agrochemical has become a matter of concern due to its persistence and potential harm to the environment and human health. Detecting and addressing DDVP contamination is crucial to protect human health and mitigate ecological impacts. Hence, this study focuses on harnessing the properties of fullerene (C60) carbon materials, known for their biological activities and high importance, to develop an efficient sensor for DDVP. Additionally, the sensor's performance is enhanced by doping it with gallium (Ga) and indium (In) metals to investigate the sensing and trapping capabilities of DDVP molecules. The detection of DDVP is carefully examined using first-principles density functional theory (DFT) at the Def2svp/B3LYP-GD3(BJ) level of theory, specifically analyzing the adsorption of DDVP at the chlorine (Cl) and oxygen (O) sites. The adsorption energies at the Cl site were determined as - 57.894 kJ/mol, - 78.107 kJ/mol, and - 99.901 kJ/mol for Cl_DDVP@C60, Cl_DDVP@Ga@C60, and Cl_DDVP@In@C60 interactions, respectively. At the O site, the adsorption energies were found to be - 54.400 kJ/mol, - 114.060 kJ/mol, and - 114.056 kJ/mol for O_DDVP@C60, O_DDVP@Ga@C60, and O_DDVP@In@C60, respectively. The adsorption energy analysis highlights the chemisorption strength between the surfaces and the DDVP molecule at the Cl and O sites of adsorption, indicating that the O adsorption site exhibits higher adsorption energy, which is more favorable according to the thermodynamics analysis. Thermodynamic parameters (∆H and ∆G) obtained from this adsorption site suggest considerable stability and indicate a spontaneous reaction in the order O_DDVP@Ga@C60 > O_DDVP@In@C60 > O_DDVP@C60. These findings demonstrate that the metal-decorated surfaces adsorbed on the oxygen (O) site of the biomolecule offer high sensitivity for detecting the organophosphate molecule DDVP.

Molecular Simulation of the Interaction of Diclofenac with Halogen (F, Cl, Br)-Encapsulated Ga12As12 Nanoclusters

Diclofenac is one of the most frequently consumed over-the-counter anti-inflammatory agents globally, and several reports have confirmed its global ubiquity in several environmental compartments. Therefore, the need to develop more efficient monitoring/sensing devices with high detection limits is still needed. Herein, quantum mechanical simulations using density functional theory (DFT) computations have been utilized to evaluate the nanosensing efficacy and probe the applicability of Ga₁₂As₁₂ nanostructure and its engineered derivatives (halogen encapsulation F, Br, Cl) as efficient adsorbent/sensor materials for diclofenac. Based on the DFT computations, it was observed that diclofenac preferred to interact with the adsorbent material by assuming a flat orientation on the surface while interacting via its hydrogen atoms with the As atoms at the corner of the GaAs cage forming a polar covalent As-H bond. The adsorption energies were observed to be in the range of -17.26 to -24.79 kcal/mol and therefore suggested favorable adsorption with the surface. Nonetheless, considerable deformation was observed for the Br-encapsulated derivative, and therefore, its adsorption energy was observed to be positive. Additionally, encapsulation of the GaAs nanoclusters with halogens (F and Cl) enhanced the sensing attributes by causing a decrease in the energy gap of the nanocluster. And therefore, this suggests the feasibility of the studied materials as potentiometric sensor materials. These findings could offer some implications for the potential application of GaAs and their halogen-encapsulated derivatives for electronic technological applications.

Modeling of magnesium-decorated graphene quantum dot nanostructure for trapping AsH3, PH3 and NH3 gases

A magnesium-decorated graphene quantum dot (C₂₄H₁₂-Mg) surface has been examined theoretically using density functional theory (DFT) computations at the ωB97XD/6-311++G(2p,2d) level of theory to determine its sensing capability toward XH₃ gases, where X = As, N and P, in four different phases: gas, benzene solvent, ethanol solvent and water. This research was carried out in different phases in order to predict the best possible phase for the adsorption of the toxic gases. Analysis of the electronic properties shows that in the different phases the energy gap follows the order NH₃@C₂₄H₁₂-Mg < PH₃@C₂₄H₁₂-Mg < AsH₃@C₂₄H₁₂-Mg. The results obtained from the adsorption studies show that all the calculated adsorption energies are negative, indicating that the nature of the adsorption is chemisorption. The adsorption energies can be arranged in an increasing trend of NH₃@C₂₄H₁₂-Mg < PH₃@C₂₄H₁₂-Mg < AsH₃@C₂₄H₁₂-Mg. The best adsorption performance was noted in the gas phase compared to the other studied counterparts. The interaction between the adsorbed gases and the surfaces shows a non-covalent interaction nature, as confirmed by the quantum theory of atoms-in-molecules (QTAIM) and non-covalent interactions (NCI) analysis. The overall results suggest that we can infer that the surface of the magnesium-decorated graphene quantum dot C₂₄H₁₂-Mg is more efficient for sensing the gas AsH₃ than PH₃ and NH₃.

Interaction of 5-Fluorouracil on the Surfaces of Pristine and Functionalized Ca12O12 Nanocages: An Intuition from DFT

The utilization of nanostructured materials for several biomedical applications has tremendously increased over the last few decades owing to their nanosizes, porosity, large surface area, sensitivity, and efficiency as drug delivery systems. Thus, the incorporation of functionalized and pristine nanostructures for cancer therapy offers substantial prospects to curb the persistent problems of ineffective drug administration and delivery to target sites. The potential of pristine (Ca₁₂O₁₂) and formyl (-CHO)- and amino (-NH₂)-functionalized (Ca₁₂O₁₂-CHO and Ca₁₂O₁₂-NH₂) derivatives as efficient nanocarriers for 5-fluorouracil (5FU) was studied at the B3LYP-GD3(BJ)/6-311++G(d,p) theoretical level in two electronic media (gas and solvent). To effectively account for all adsorption interactions of the drug on the investigated surfaces, electronic studies as well as topological analysis based on the quantum theory of atoms in molecules (QTAIM) and noncovalent interactions were exhaustively utilized. Interestingly, the obtained results divulged that the 5FU drug interacted favorably with both Ca₁₂O₁₂ and its functionalized derivatives. The adsorption energies of pristine and functionalized nanostructures were calculated to be -133.4, -96.9, and -175.6 kcal/mol, respectively, for Ca₁₂O₁₂, Ca₁₂O₁₂-CHO, and Ca₁₂O₁₂-NH2. Also, both topological analysis and NBO stabilization analysis revealed the presence of interactions among O₃-H₃₂, O₂₇-C₂₄, O₁₀-C₂₇, and N₂₄-H₃₂ atoms of the drug and the surface. However, 5FU@Ca₁₂O₁₂-CHO molecules portrayed the least adsorption energy due to considerable destabilization of the molecular complex as revealed by the computed deformation energy. Therefore, 5FU@Ca₁₂O₁₂ and 5FU@Ca₁₂O₁₂-NH₂ acted as better nanovehicles for 5FU.

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

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

Probing the Reactions of Thiourea (CH4N2S) with Metals (X = Au, Hf, Hg, Ir, Os, W, Pt, and Re) Anchored on Fullerene Surfaces (C59X)

Upon various investigations conducted in search for a nanosensor material with the best sensing performance, the need to explore these materials cannot be overemphasized as materials associated with best sensing attributes are of vast interest to researchers. Hence, there is a need to investigate the adsorption performances of various metal-doped fullerene surfaces: C₅₉Au, C₅₉Hf, C₅₉Hg, C₅₉Ir, C₅₉Os, C₅₉Pt, C₅₉Re, and C₅₉W on thiourea [SC(NH₂)₂] molecule using first-principles density functional theory computation. Comparative adsorption study has been carried out on various adsorption models of four functionals, M06-2X, M062X-D3, PBE0-D3, and ωB97XD, and two double-hybrid (DH) functionals, DSDPBEP86 and PBE0DH, as reference at Gen/def2svp/LanL2DZ. The visual study of weak interactions such as quantum theory of atoms in molecule analysis and noncovalent interaction analysis has been invoked to ascertain these results, and hence we arrived at a conclusive scientific report. In all cases, the weak adsorption observed is best described as physisorption phenomena, and CH₄N₂S@C₅₉Pt complex exhibits better sensing attributes than its studied counterparts in the interactions between thiourea molecule and transition metal-doped fullerene surfaces. Also, in the comparative adsorption study, DH density functionals show better performance in estimating the adsorption energies due to their reduced mean absolute deviation (MAD) and root-mean-square deviation (RMSD) values of (MAD = 1.0305, RMSD = 1.6277) and (MAD = 0.9965, RMSD = 1.6101) in DSDPBEP86 and PBE0DH, respectively.

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

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

Computational study on the interactions of functionalized C24NC (NC = C, -OH, -NH2, –COOH, and B) with chloroethylphenylbutanoic acid

Computational chemistry approach based on density functional theory (DFT) was utilized to investigate the interaction, adsorption behaviour, electronic and structural properties of nanostructured complexes formed by4-(4-(bis(2-chloroethyl) amino) phenyl) butanoic acid (CPB) and all carbon fullerene nanocage, (C24NC), Boron functionalized carbon nanocage (C24NC@B@CPB), Carboxylate functionalized (C24NC@COOH@CPB), amino functionalized (C24NC@NH2@CPB) and hydroxy functionalized (C24NC@OH@CPB) nanostructured materials. To understand effectively the interaction of the drug and surface, topological analysis was conducted via the atoms in molecule (QTAIM) and NCI approach. Electronic properties such as quantum chemical descriptors, NBO and NLO are equally considered and reported. All computations were achieved at the B3LYP-D3 and ωB97XD levels of theory with the 6-311++G(d,p) basis set. The results indicate that the adsorption energy of CPB on C24NC and its functionalized derivatives are in the range of -0.52 to 2.89 eV indicating that physisorption and chemisorption mechanism are prevalent mechanisms of adsorption. C23B@CPB, C24OH@CPB, and C24NH2@CPB were observed to possess the best characteristics to be considered as transport vehicles for CPB due to their strong adsorption nature (chemisorption) and solubility in solution.

Metal-Doped Al12N12X (X = Na, Mg, K) Nanoclusters as Nanosensors for Carboplatin: Insight from First-Principles Computation

This theoretical study focuses on the adsorption, reactivity, topological analysis, and sensing behavior of metal-doped (K, Na, and Mg) aluminum nitride (Al12N12) nanoclusters using the first-principle density functional theory (DFT). All quantum chemical reactivity, natural bond orbital (NBO), free energies (ΔG, ΔH), and sensor parameters were investigated using the ωB97XD functional with the 6-311++G(d,p) basis set. The trapping of carboplatin (cbp) onto the surfaces of doped Al12N12 was studied using four functionals PBE0-D3, M062X-D3, ωB97XD, and B3LYP-D3 at the 6-311++G(d,p) basis set. Overall, the substantial change in the energy gap of the surfaces after the adsorption process affects the work function, field emission, and the electrical conductivity of the doped clusters, hence making the studied surfaces a better sensor material for detecting carboplatin. Higher free energies of solvation were obtained in polar solvents compared to nonpolar solvents. Moreover, negative solvation energies and adsorption energies were obtained, which therefore shows that the engineered surfaces are highly efficient in trapping carboplatin. The relatively strong adsorption energies show that the mechanism of adsorption is by chemisorption, and K- and Na-doped metal clusters acted as better sensors for carboplatin. Also, the topological analysis in comparison to previous studies shows that the nanoclusters exhibited very high stability with regard to their relevant binding energies and hydrogen bond interactions.

Meta-Hybrid Density Functional Theory Prediction of the Reactivity, Stability, and IGM of Azepane, Oxepane, Thiepane, and Halogenated Cycloheptane

The application of plain cycloalkanes and heterocyclic derivatives in the synthesis of valuable natural products and pharmacologically active intermediates has increased tremendously in recent times with much attention being paid to the lower cycloalkane members. The structural and molecular properties of higher seven-membered and nonaromatic heterocyclic derivatives are less known despite their stable nature and vast application; thus, an insight into their structural and electronic properties is still needed. Appropriate quantum chemical calculations utilizing the ab initio (MP2) method, meta-hybrid (M06-2X) functional, and long-range-separated functionals (ωB97XD) have been utilized in this work to investigate the structural reactivity, stability, and behavior of substituents on cycloheptane (CHP) and its derivatives: azepane, oxepane, thiepane, fluorocycloheptane (FCHP), bromocycloheptane (BrCHP), and chlorocycloheptane (ClCHP). Molecular global reactivity descriptors such as Fukui function, frontier molecular orbitals (FMOs), and molecular electrostatic potential were computed and compared with lower members. The results of two population methods CHELPG and Atomic Dipole Corrected Hirshfeld Charges (ADCH) were equally compared to scrutinize the charge distribution in the molecules. The susceptibility of intramolecular interactions between the substituents and cycloalkane ring is revealed by natural bond orbital analysis and intramolecular weak interactions by the independent gradient model (IGM). Other properties such as atomic density of states, intrinsic bond strength index (IBSI), and dipole moments are considered. It is acclaimed that the strain effect is a major determinant effect in the energy balance of cyclic molecules; thus, the ring strain energies and validation of spectroscopic specificities with reference to the X-ray crystallographic data are also considered.

Exploring steric and electronic parameters of biaryl phosphacycles

Steric and electronic parameters of the newly developed biaryl phosphacycles derived from the phobane[3.3.1] (Phob) and phosphatrioxa-adamantane (Cg) moieties were quantified from various experimental and theoretical methods.

Structural-topological preferences and protonation sequence of aliphatic polyamines: a theoretical case study of tetramine trien

A large set of lowest and medium energy conformers of aliphatic tetramine trien was used to uncover structural-topological preferences of poliamines. Numerous common structural features among HL and H 2 L tautomers were identified, e.g., H-atoms of protonated functional groups are always involved in intramolecular NH•••N interactions and they result in as large and as many as possible rings in lowest energy conformers. Largest, 11-membered, molecular rings stabilize a molecule most and they appeared to be strain free whereas 5-memebred intramolecular rings were most strained (all formed due to NH•••N interactions). The CH•••HC interactions with QTAIM-defined atomic interaction lines were also found but, surprisingly, mainly in the lowest energy conformers of HL tautomers. According to the non-covalent interaction-based (NCI) analysis, 5-memebered rings formed by CH•••HC interactions are not strained and, in general, 3D NCI isosurfaces mimic those obtained for weaker NH•••N interactions. Also, 3D NCI isosurfaces found for NH•••N and CH•••HC interactions, regardless whether linked or not by an atomic interaction line, appeared to be indistinguishable. Using lowest energy conformers, theoretically predicted mixture of primary (HL p ) and secondary (HL s ) forms of trien was found to be in accord with the literature reports; using linear conformers resulted in predicting HL s as the only tautomer formed. In contrast to HF, the overall performance of B3LYP was found satisfactory for the purpose of the study.

2,2'-(Piperazine-1,4-di-yl)diethanaminium bis-(2-hy-droxy-benzoate)

The asymmetric unit of the title salt, C₈H₂₂N₄²⁺·2C₇H₅O₃⁻, comprises half a 2,2′-(piperazine-1,4-di­yl)diethan­aminium dication plus a 2-hy­droxy­benzoate anion. In the crystal, the anions and cations are linked by N—H⋯O and O—H⋯O hydrogen bonds to form infinite two-dimensional networks parallel with the a unit-cell face. The conformation adopted by the cation in the crystal is very similar to that adopted by the same cation in the structures of the nitrate and tetra­hydrogen penta­borate salts.

3,6-Diaza-octane-1,8-diaminium diiodide

The asymmetric unit of the title salt, C₆H₂₀N₄²⁺·2I⁻, comprises half a 3,6-diaza­octane-1,8-diaminium dication plus an I⁻ anion. The dications are symmetrical and lie across crystallographic centres of inversion. In the crystal, the ions form a network involving mainly weak N—H⋯I inter­molecular inter­actions: two H atoms of the ammonium group form inter­actions with two I⁻ anions and the H atom of the secondary amine forms a weak inter­action with a third I⁻ cation. The third ammonium H atom is hydrogen bonded to a secondary amine of an adjacent cation. The backbone of the cation does not form a uniformly trans chain, but is ‘kinked’ [C—N—C—C torsion angle = 71.5 (2)°], probably to accommodate the direct hydrogen bond between the ammonium group and the secondary amine in an adjacent cation.

2,2'-(Piperazine-1,4-di-yl)diethanaminium dibenzoate

The asymmetric unit of the title salt C(8)H(22)N(4) (2+)·2C(7)H(5)O(2) (-), comprises two independent pairs of half a 2,2'-(piperazine-1,4-di-yl)diethanaminium dication plus a benzoate anion. The dications are symmetrical and lie across crystallographic centres of inversion. The crystal structure was refined as a two-component pseudo-merohedral twin using the twin law 001 0-10 100 [he domain fractions are 0.8645 (8) and 0.1355 (8)]. The anions and cations are linked by N-H⋯O hydrogen bonds and weak N-H⋯O inter-molecular inter-actions to form infinite two-dimensional networks parallel to [101]. The conformation adopted by the cation in the crystal structure is very similar to that adopted by the same cation in the structures of the 2-hy-droxy-benzoate [Cukrowski et al. (2012 ▶). Acta Cryst, E68, o2387], the nitrate and the tetra-hydrogen penta-borate salts.