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In this research, the density functional theory (DFT) calculations were carried out for investigation non-bonded interaction between the anticancer drug Fludarabine (Fludara) with sugar molecule (2S,3R,4S,5S)-2-(hydroxymethyl)-3,5-dimethyloxolane-3,4-diol (OXO) by using B3LYP/6-311+G* level of theory in the solvent water. The electronic spectra of the Fludara drug and Fludara/OXO complex in solvent water were calculated by time dependent density functional theory (TD-DFT) for the study of intermolecular interaction effect. The non-bonded interaction effects of the Fludara drug with OXO on the electronic properties, natural charges and chemical shift tensors have been also detected. The results display the change in title parameters after interaction process. According to the natural bond orbital (NBO) results, the Fludara molecule and OXO play as both electron donor and acceptor at the Fludara/OXO complex. On the other hand, the charge transfer is occurred between the bonding, antibonding or nonbonding orbitals in two molecules drug and OXO.

The aim of this work is a study of the encapsulation and intermolecular non-bonded interaction of an anticancer drug Talzenna into carbon nanotube [CNT(8,8-7)] and boron nitride nanotube [BNNT(8,8-7)]. The interaction effects of Talzenna with the CNT and BNNT on electronic and adsorption properties were theoretically investigated in the solvent phase at the M062X/6-311G* level of theory. With the encapsulation of Talzenna drug, the electronic properties of the CNT and BNNT nanotubes change significantly. The electronic spectra of the Talzenna drug, complexes CNT/Talzenna and BNNT/Talzenna in the solvent water were calculated by Time-Dependent Density Functional Theory (TD-DFT) for the study of adsorption effect. According to the natural bond orbital (NBO) results, all three molecules Talzenna, CNT and BNNT play as electrons donor and acceptors at the complexes CNT/Talzenna and BNNT/Talzenna. On the other hand, the charge transfer is occurred between the bonding, antibonding or nonbonding orbitals in molecules Talzenna, CNT and BNNT. Based on the results, CNT(8,8-7) and BNNT(8,8-7) can be used as a drug delivery system for the transportation of Talzenna as anticancer drug within the biological systems.

In the current study, the adsorption properties of the molecule (4E,6E)-4-(4-hydroxyphenyldiazenyl)-N-((furan-2-yl)methylene)benzenamine (AZO) on BN(6,6-8) nanotube was studied by density functional theory (DFT) in the gaseous phase for the first time. The non-bonded interaction effects of compounds AZO and BN(6,6-8) nanotube on the electronic properties, and natural charge were investigated and discussed. The electronic spectra of the compound AZO and the complex BN(6,6-8)/AZO were calculated by time dependent density functional theory (TD-DFT) for investigation of the maximum wavelength value of the AZO before and after the non-bonded interaction with the BN(6,6-8) nanotube and molecular orbitals involved in the formation of absorption spectrum of the complex AZO at maximum wavelength.

Non-covalent interactions have been investigated in several orientations of (4E,4E)-4-(4-hydroxyphenyldiazenyl)-N-((furan-2-yl)methylene)benzenamine/armchair single-wall boron nitride nanotube [EE-HPDFMB/SWBNNT] complexes at ωB97X-D/6-31G(d) level of theory. Global reactivity indexes show electrophile and nucleophile roles of EE-HPDFMB and SWBNNT, respectively. This result confirms molecular electrostatic potential maps and low HOMOSWBNNT–LUMOEE-HPDFMB gap. These interactions as weak forces can cause a physical adsorption and encapsulation of EE-HPDFMB with medicinal properties in the SWBNNT. More negative values (− 25.7 and − 47.2 kJ mol−1) of adsorption energy including zero point energy and basis set superposition error corrections ($$D_{\text{e}}^{0}$$) in the inside complexes show better adsorption strength, stable configuration and small red shift than outside. This issue mainly results from existence of the several π–π and CH–π stacking interactions in the inside complexes. More importantly, obtained electron density ρ(r) and Laplacian ∇2ρ(r) from QTAIM analysis reveal that the π–π stacking in the inside is stronger than outside complex. Low second-order stabilization energies in the in/outside complexes are confirmation for these non-covalent interactions in electron view point.

In the present work the adsorption properties of the molecule Resveratrol (RSV) (trans-3,5,4′-Trihydroxystilbene) on CNT(8,0-10) nanotube was investigated by Density Functional Theory (DFT) in the gaseous phase for the first time. The non-bonded interaction effects of compounds RSV and CNT(8,0-10) nanotube on the electronic properties, chemical shift tensors and natural charge were determined and discussed. The electronic spectra of the RSV and the complex CNT(8,0-10)/RSV in the gaseous phase were calculated by Time Dependent Density Functional Theory (TD-DFT) for investigation of the maximum wavelength value of the RSV before and after the non-bonded interaction with the CNT(8,0-10) nanotube and molecular orbitals involved in the formation of absorption spectrum of the complex RSV at maximum wavelength.

In the present work, Density Functional Theory (DFT) was first time employed to investigate the interaction between new drug (6aR,10aR)-6,6,9-trimethyl-3-pentyl-6a,7,8,10a-tetrahydrobenzo[c]chromen-1-ol (Syndros) and the CNT(6,6-6) Nanotube in the gaseous phase. The interaction effects of compounds Syndros and CNT (6,6-6) nanotube on the electronic properties, chemical shift tensors and natural charge was also determined and discussed. The electronic spectra of the Syndros and the complex CNT(6,6-6)/Syndros in the gas phase were calculated by Time Dependent Density Functional Theory (TD-DFT) for the formation of adsorption effect on maximum wavelength of the Syndros. Nucleus-Independent Chemical Shifts (NICS) calculations have also been carried out for the compound Syndors and the complex CNT(6,6-6)/Syndros and the aromaticity of the compound Syndors before and after interaction with the CNT(6,6-6) Nanotube was investigated.

In the present work, the quantum theoretical calculations of the molecular structures of the four new synthesized azomethine dyes such as: 1. ( E )- N -(4-butoxybenzylidene)-4-(( E )-phenyldiazenyl)aniline (PAZB-6), 2. ( E )- N -(4-(benzyloxy)benzylidene)-4-(( E ))-phenyldiazenyl)aniline (PAZB-7), 3. 4-(( E )-4-(( E )-phenyldiazenyl)phenyl)imino)methyl)phenol (PAZB-8), 4. ( E )- N -(4-methoxybenzylidene)-4-(( E ))-phenyldiazenyl)aniline (PAZB-9) have been predicted using Density Functional Theory in the solvent Dimethylformamide. The geometries of the azomethine dyes were optimized by PBE1PBE/6-31+G* level of theory. The electronic spectra of the title compounds in the solvent DMF was carried out by TDPBE1PBE/6-31+G* method. FT-IR spectra of the title compounds are recorded and discussed. Frontier molecular orbitals, molecular electrostatic potential, electronic properties, natural charges and Natural Bond Orbital (NBO) analysis of the mentioned compounds were investigated and discussed by theoretical calculations. The azomethine dyes were synthesized after quantum chemical modeling for optical applications. A new study of anisotropy of thermal and electrical conductivity of the colored stretched PVA-films have been undertaken.

In this present work, first time interaction between new synthesized derivative of the 4-((E)-((4-((E)-phenyldiazenyl)phenyl)imino)methyl)benzoic acid (E-PABA) and the BN(6,6-7) Nanotube for medical applications were studied. The geometries of the compounds E-PABA, the BN(6,6-7) Nanotube and the Complex BN(6,6-7)/E-PABA were optimized by Density Functional Theory (DFT) in the gas phase. The adsorption effect of the compound E-PABA on the electronic properties, chemical shift tensors and natural charge of the BN(6,6-7) Nanotube was investigated and discussed. The electronic spectra of the E-PABA and the Complex BN(6,6-7)/E-PABA in the gas phase carried out by Time Dependent Density Functional Theory (TD-DFT) for the foundation adsorption effect on maximum wavelength of the E-PABA.

In the current work, density functional theory calculations were carried out to evaluate the potential ability of apomorphine, dopamine, hinokitiol and deferiprone chelating agents to coordinate Mn2+, Fe3+ and Zn2+ metal ions with a 1:1 ratio in water solution. The binding energy values reveal that Zn2+/chelating agent complexes are more stable compared to Mn2+/chelating agent and Fe3+/chelating agent complexes. In order to evaluate the parameters that describe the affinity between the metal ions and chelating agents, the metal ion/chelating agent interactions were analyzed by CDA, NBO, QTAIM, FMO analyses. Interestingly, it was found that the Fe O interactions in all complexes and Mn O interactions in [Mn-DFP]+ complex are mainly electrostatic, whereas other interactions have a covalent character. Moreover, TD-DFT studies showed n → π* and π → π* transitions in the absorption spectra of the complexes.

Background: In the present study, the interaction between new drug Rubraca and CNT(4,4-8) nanotube by Density Functional Theory (DFT) calculations in an aqueous medium for first time have been investigated. Method and Results: According to calculations, the intermolecular hydrogen bonds take place between active positions of the molecule Rubraca and hydrogen atoms of the nanotube that plays an important role in the stability of the complex CNT(4,4- 8)/Rubraca. The non-bonded interaction effects of the molecule Rubraca with CNT(4,4- 8) nanotube on the electronic properties, chemical shift tensors and natural charge have been also detected. The natural bond orbital (NBO) analysis suggested that the molecule Rubraca as an electron donor and the CNT(4,4-8) nanotube plays the role an electron acceptor at the complex CNT(4,4-8)/Rubraca. The electronic spectra of the Rubraca drug and the complex CNT(4,4-8)/Rubraca were also calculated by Time Dependent Density Functional Theory (TD-DFT) for the investigation of adsorption effect of the Rubraca drug over nanotube. Conclusion: The use of CNT(4,4-8) nanotube for Rubraca delivery to the diseased cells have been established.