DFT Computational Studies Research Articles

Novel Ball-Type Phthalocyanines with Eight Benzotriazole Groups: Synthesis, Computational DFT Studies, and Supercapacitor Properties

Abstract Novel four MBTOB-bridged ball-type metallophthalocyanines were obtained from 4, 4'-((methylenebis(6-(2H-benzo[d][1, 2, 3]triazol-2-yl)-4-(2, 4, 4-trimethylpentan-2-yl)-2, 1-phenylene))bis(oxy))diphthalonitrile by means of transition metal (II) acetate salts in 2-dimethylaminoethanol. The new starting bisphthalonitrile compound was accomplished from 2,2'-methylenebis[6-(benzotriazol-2-yl)-4-tert-octylphenol] and 4-nitrophthalonitrile in dimethylformamide under the catalysis of potassium carbonate at 50○C. The structural characterization of the compounds was accomplished by infrared, proton-nuclear magnetic resonance, matrix-assisted laser desorption/ionisation time-of-flight mass, and ultraviolet–visible spectroscopic methods. The supercapacitor performances of the electrodes were examined by cyclic voltammetry, galvanostatic charge discharge, and electrochemical impedance spectroscopy analyses. The specific capacitances obtained from the GCD measurements were calculated as 320.4 ± 15.1 F/g for ball-type zinc (II) phthalocyanine in three electrode systems. The highest specific capacitance value was found in the electrode containing ball-type nickel (II) phthalocyanine as 929.8 ± 32.8 F/g at a scan rate of 100 mV/s. In symmetric supercapacitor measurements, the capacitance retention value was 100.7% after 5000 cycles.

Effect of radical groups on the magnetic properties of [7]helicene derivatives: a DFT computational study

Effect of radical groups on the magnetic properties of [7]helicene derivatives: a DFT computational study

Naphthalene Diimide and Bis-Heteroleptic Ru(II) Complex-Based Hybrid Molecule with 3-in-1 Functionalities.

Multipurpose applications of a newly developed homobimetallic Ru(II) complex, Ru-NDI[PF6]4, which incorporates 1,10-phenanthroline and triazole-pyridine ligands and linked via a (-CH2-)3 spacer to the reputed anion-π interacting NDI system, are described. Solution-state studies of the bimetallic complex, including EPR, PL, UV-vis, and NMR experiments, reveal two sequential one-electron transfers to the NDI unit, generating NDI⋅- and NDI2- in the presence of F- selectively. This process inhibits the primary electron transfer from Ru(II) to the NDI unit, thereby allowing the 3MLCT-based emission of the complex to be recovered, resulting in a corresponding ten-fold increase in luminescence intensity. DFT and TD-DFT computational studies further elucidate the experimentally observed absorption spectra of the complex. Secondly, CT-DNA binding studies with the complex are performed using various spectroscopic analyses such as UV-vis, PL, and CD. Comparative DNA binding studies employing EB and molecular docking reveal that the binding with CT-DNA occurs through both intercalative and groove binding modalities. Thirdly, the photocatalytic activities of the complex towards C-C, C-N, and C-O bond formation in organic cross-coupling reactions, including the amidation of α-keto acids to amines and the oxidation of alcohol to aldehydes, are also demonstrated.

Synthesis, characterization, DFT computational studies and biological activity of transition metal complexes derived from 4-(((6-nitrobenzo[d]thiazol-2-yl)imino)methyl)benzene-1,3-diol

A series of Co(II), Ni(II), Cu(II), Zn(II) complexes have been synthesized with a benzothiazole azo dye containing tridentate (NNO) donor ligand 4-(((6-nitrobenzo[d]thiazol-2-yl)imino)methyl)benzene-1,3-diol derived from 2-amino-6-nitrobenzothiazole and 2,4-dihydroxybenzaldehyde. The structures of the novel ligand and metal complexes were identified and confirmed via various spectroscopic techniques (FT-IR,1H NMR,13C NMR, UV-Vis, mass spectrometry), TGA-DTA, powder X-ray diffraction, and DFT calculations. The optimal structural parameters and chemical reactivity of the ligand and metal complexes have been investigated using Density Functional Theory calculations (DFT/B3LYP,6-31G** and LanL2DZ basis sets) to provide insight about their frontier molecular orbitals (FMO) and molecular electrostatic potential (MESP). In vitro DPPH radical scavenging techniques have been used to assess the antioxidant activity of the ligand and complexes, indicating good antioxidant activity. The Ni(II) complex was the most potent with the lowest IC50 values. The in vitro antibacterial activities have been explored by screening against bacteria (Bacillus subtilis) and bacteria (E. coli) exhibiting significant activity against the tested strains of bacteria with Zn(II) complex as most potent with the lowest MIC value against E. coli and B. subtilis) and highest zone of inhibition against E. coli and B. subtilis at 1000 μg/mL concentration). The antifungal activity of complexes against Aspergillus niger and Candida albicans indicate that the Co(II) complex is most active for C. albicans and Zn(II) complex for A. niger .

Air-stable Palladium N-Heterocyclic Carbene based CCC-NHC Pincer Complexes: Synthesis, Characterization, Photophysical and Raman Vibrational Studies, and DFT Studies, Plus Observation of an Abnormal Carbene Pincer

A series of CCC-NHC pincer Pd(II)X complexes, where X = Cl, Br, or I, were synthesized by a metalation/transmetalation reaction sequence and characterized by NMR and Raman spectroscopy, photophysical studies, X-ray crystallography, and DFT computational studies. This is the first detailed report of the CCC-NHC pincer Pd complexes analogous the previously reported Pt analogs. Photophysical measurements show that by varying the X ligand, the emission wavelength can be tuned. The chloride complex is a water and air stable blue emitter with a quantum yield of 46% and all three complexes have photostabilities >90%. A combined DFT and TD-DFT study has been carried out to investigate ground state and excited state geometries as well as absorption and emission processes of CCC-NHC Pd complexes. Theoretical results were compared with the corresponding experimental results and showed good agreement. Raman spectroscopy (computational and experimental) was used to examine Pd-X vibrations which have been rarely reported in the literature. Several by-products of the metalation/transmetalation procedure were identified. A rare mixed normal/abnormal carbene pincer Pd(II)Cl complex was isolated and crystallographically characterized.

Synthesis, structural, DFT computation, and nonlinear absorption studies of DL-methioninium maleate

Synthesis, structural, DFT computation, and nonlinear absorption studies of DL-methioninium maleate

A Well-Defined Magnesium Complex of C70 6.

Controlling and understanding charge state and metal coordination in carbon nanomaterials is crucial to harnessing their unique properties. Here we describe the synthesis of the well-defined fulleride complex [{(Mesnacnac)Mg}6C70], 2, (Mesnacnac)=HC(MeCNMes)2, Mes=2,4,6-Me3C6H2, from the reaction of the β-diketiminate magnesium(I) complex [{(Mesnacnac)Mg}2] with C70 in aromatic solvents. The molecular structure of complex 2 was determined, providing the first high-quality structural study of a complex with the C70 6- ion. In combination with solution state NMR spectroscopic and DFT computational studies, the changes in geometry and charge distribution in the various atom and bond types of the fulleride unit were investigated. Additionally, the influence of the (Mesnacnac)Mg+ cations on the global and local fulleride coordination environment was examined.

MgTe for efficient adsorption of lithium-ion battery fault gases (H2, CO, and CO2) and failure risk index calculation: A DFT computational study

In recent years, lithium-ion batteries have been used in bulk for the development of new energy vehicles. Studying fault gas adsorption in lithium-ion batteries is crucial to their safe operation. This study constructs and optimizes the adsorption model for fault gases adsorbed on the MgTe monolayer. Analysis of the energy- and electron-related adsorption properties indicates that the MgTe monolayer has a strong adsorption effect on lithium-ion battery failure gases. Meanwhile, the value of Eads increases as the gas coverage expands, with CO showing the greatest increase at 144.79%. Secondly, the conductivity change response of CO adsorption on MgTe is obvious, and the Desorption Time is considerable, indicating its potential as a long-life adsorbent. Furthermore, the Risk Index is defined by the change of Eads (CO), and a strong correlation between the Risk Index and lithium-ion batteries is obtained. This study provides a new idea for lithium-ion battery failure warning and is of great value for the widespread application of new energy.

An Investigation of Novel Series of 2-Thioxo-1,3-dithiol-carboxamides as Potential Antispasmodic Agents: Design, Synthesis via Coupling Reactions, Density Functional Theory Calculations, and Molecular Docking.

This study reports the synthesis of 2-thioxo-1,3-dithiol-carboxamides (TDTCAs) under mild conditions at room temperature using HBTU as a coupling agent, which significantly improved amide bond formation. The synthesized compounds were characterized using several analytical techniques, including 1H and 13C NMR spectroscopy, and HRMS, confirming their intended structures and structural integrity. A DFT computational study at the B3LYP/6-31G(d,p) level was conducted on the four synthesized compounds to compare their electronic properties and molecular structures. The results showed that these compounds demonstrated antispasmodic effects on jejunum contractions. Molecular docking revealed that compounds c and d displayed the highest docking scores on potassium and voltage-gated calcium channels and adrenergic receptors. In summary, compounds c and d exhibit antispasmodic effects, potentially blocking alpha-adrenergic receptors and calcium channels, thus providing a scientific basis for their potential use in treating gastrointestinal disorders.

Rigid Macrocycle Metal Complexes as CXCR4 Chemokine Receptor Antagonists: Influence of Ring Size.

Understanding the role of chemokine receptors in health and disease has been of increasing interest in recent years. Chemokine receptor CXCR4 has been extensively studied because of its defined role in immune cell trafficking, HIV infection, inflammatory diseases, and cancer progression. We have developed high affinity rigidified CXCR4 antagonists that incorporate metal ions to optimize the binding interactions with the aspartate side chains at the extracellular surface of the CXCR4 chemokine receptor and increase the residence time. Cross- and side-bridged tetraazamacrocylic complexes offer significant advantages over the non-bridged molecular structures in terms of receptor affinity, potential for radiolabelling, and use in therapeutic applications. Our investigation has been extended to the influence of the ring size on bridged tetraazamacrocyclic compounds with the addition of two novel chelators (bis-cross-bridged homocyclen and bis-cross-bridged cyclen) to compare to the bis-bridged cyclam, along with novel metal complexes formed with copper(II) or zinc(II). The in vitro biological assays showed that all of the zinc(II) complexes are high affinity antagonists with a marked increase in CXCR4 selectivity for the bis-cross-bridged cyclen complex, whereas the properties of the copper(II) complexes are highly dependent on metal ion geometry. X-ray crystal structural data and DFT computational studies allow for the rationalisation of the relative affinities and the aspartate residue interactions on the protein surface. Changing the ring size from 14-membered can increase the selectivity for the CXCR4 receptor whilst retaining potent inhibitory activity, improving the key pharmacological characteristics.

DFT computational and mass spectrometry studies of intermolecular interaction of β-cyclodextrin with nifedipine

A systematic investigation of intermolecular interactions of β- cyclodextrin(β-CD)and Nifedipine(Nif)in gas phase and in water were done by the mass spectrometry and DFT calculation method. The results obtained clearly indicated that the aromatic ring containing the nitro moiety of Nifedipine inverted into the wider rim of β cyclodextrin, the high collision induced dissociation (CID) energy in mass spectrometry experiments demonstrated the stability of the 1:1 Nif-β-CD complexes. Compared to the native β-CD, HP- β-CD and DM- β-CD are more easily to form complexes with Nif due to their approximately double lower binding energy, the thermodynamic parameters, HOMO, LUMO, the global reactivity descriptors of these complexes were calculated and interpreted. Furthermore, the study of natural bonding orbitals (NBO) and quantum theory of protons in molecules (QTAIM) supports the existence of various hydrogen bonds and van der Waals interactions in three complex structures, as predicted by chemical bonding principles. IGMH analysis give the visualized origin of weak attractive interactions between the CDs and the Nifedipine.

Sustainable biodiesel production via castor oil transesterification using organotin(IV) compounds as catalysts

The rapid reduction in fossil fuel reserves and their environmental effects has caused a serious threat to humanity. Meanwhile, the exponential increase in the usage of fossil fuels demands the exploration of new energy sources. Therefore, this work was designed keeping in view the today need of the World for renewable energy source. The 4-(4-chloro-2-fluorophenylamino)-4-oxobut-2-enoic acid based organotin(IV) carboxylates were prepared and characterized by FT-IR, NMR and single crystal XRD analysis. Due to the Lewis acid character of Sn(IV) centre confirmed by DFT computational study, the synthesized compounds were used as catalysts for the transesterification of castor oil for biodiesel production. Under the optimized experimental conditions, the catalytic performance of the tested compounds was found as follow: 1 > 3 > 2 > 4 > 6 > 5 > 7. The obtained biodiesel was confirmed by FT-IR, NMR and GC–MS. The fuel properties of the obtained biodiesel were also determined and compared with American Standard (ASTM D-6751). Based on their catalytic performance, these compounds might be the potential future candidates for the expansion of catalyst systems for efficient biodiesel production from the various feedstocks.

Oxidative and Extractive Desulfurization of Fuel Oils Catalyzed by N-Carboxymethyl Pyridinium Acetate and N-Carboxyethyl Pyridinium Acetate Acidic Ionic Liquids: Experimental and Computational DFT Study

Oxidative and Extractive Desulfurization of Fuel Oils Catalyzed by <i>N</i>-Carboxymethyl Pyridinium Acetate and <i>N</i>-Carboxyethyl Pyridinium Acetate Acidic Ionic Liquids: Experimental and Computational DFT Study

Comparative Vibrational analysis, Electronic Properties, and molecular docking of Lantadene A and B (Potential anticancer agents) - A Computational DFT Study

Abstract. We conducted a comprehensive analysis of Lantadene A and B using FTIR spectroscopy, beginning with geometry optimization. Subsequently, we calculated their fundamental vibrational frequencies and intensities using the B3LYP/6-311G (d, p) method. To provide a thorough vibrational assignment, we utilized potential energy distribution (PED). The results from our calculated spectra closely matched the experimental data, demonstrating the accuracy of our calculations. Furthermore, we assessed the electronic properties of Lantadene A and B. We computed the HOMO-LUMO gap and visualized the frontier orbital HOMO-LUMO surfaces, as well as Molecular Electrostatic Potential (MEP) surfaces. These analyses shed light on the reactive nature of these compounds, highlighting their potential applications. Moreover, our investigation explored the hyper-polarizability values, suggesting that Lantadene A and B hold promise for electro-optical applications due to their unique properties. Additionally, we conducted docking studies of Lantadene A and Lantadene B with BCL2L1 (BCL2 like 1) and IKBKB (inhibitor of nuclear factor kappa B kinase subunit beta) proteins, as provided by HGNC. These analyses revealed promising interactions, supporting the potential use of Lantadene A and B as agents with anti-cancer and anti-inflammatory properties. In summary, our research indicates that Lantadene A and B possess properties that make them strong candidates for use in the development of anticancer and anti-inflammatory agents, while also showing promise for electro-optical applications. Resumen. Utilizando la espectroscopía de FTIR realizamos un análisis integral de lantadeno A y B, empezando con la optimización de sus geometrías. Después, calculamos las frecuencias e intensidades de vibración utilizando el método B3LYP/6-311G (d, p). Para realizar una asignación vibracional exhaustiva, utilizamos la distribución de energía potencial (PED). Los espectros calculados están en buen acuerdo con los experimentales, lo cual demuestra la precisión de nuestros cálculos. Además, evaluamos las propiedades electrónicas de lantadeno A y B. Calculamos la brecha (gap) HOMO-LUMO, visualizamos las isosuperficies de los orbitales frontera, y también las isosuperficies del potencial electrostático molecular (MEP). Estos análisis ayudan a esclarecer la reactividad de estas moléculas, destacando sus aplicaciones potenciales. Se exploraron los valores de las hiperpolizabilidades las cuales sugieren que el lantadeno A y B son compuestos prometedores para aplicaciones electroópticas. Adicionalmente, se realizaron estudios de acoplamiento molecular de lantadeno A y B con las proteínas BCL2L1 (BCL2 como 1) y IKBKB (inhibidor del factor kappa B de la subunidad beta quinasa), que se obtuvieron del HGNC. Estos análisis mostraron interacciones prometedoras, que apoyan el uso potencial de lantadeno A y B como agentes anticancerígenos y con propiedades antinflamatorias. En síntesis, nuestra investigación indica que las propiedades del lantadeno A y lantadeno B las hacen buenos candidatos para su uso en el desarrollo de agentes anticancerígenos y antinflamatorios, además de también mostrar potencial en aplicaciones electroópticas.

Combined DFT and ionic model computational study of the effect of alkali metal cations on the structure, bonding and properties of molten cryolites, M3AlF6 (M = li, Na, K, Rb, and Cs)

ABSTRACT Ionic melts, in the form of ionic liquids and molten salts, are important in many technological aspects such as metal production and energy applications. Cryolite melts constitute an important family especially for the industrial production of Al. The present computational study aims to analyse the effect of different cations on the structure and properties of Al (III) fluorocomplexes in cryolite melts. Cation effects are discussed as the ion pair interactions due to alkali metal cations of cryolite compounds M3AlF6 with M= Li, Na, K, Rb, or Cs for various microclusters using ionic interaction model (IM) and DFT calculations. DFT results for different ion complexes are compared with the energy calculations using a pseudoclassical model for isolated clusters. QTAIM and ELF analyses were performed to understand the nature of interactions in detail. A link between open-shell interactions and decreased ionic conductivity is proposed within the series of K, Rb, and Cs. Environmental effects, such as temperature and presence of other ions, are investigated in detail by DFT analysis.

Reaction of Pyrrolobenzothiazines with Schiff Bases and Carbodiimides: Approach to Angular 6/5/5/5-Tetracyclic Spiroheterocycles.

1H-Pyrrole-2,3-diones, fused at [e]-side with a heterocycle, are suitable platforms for the synthesis of various angular polycyclic alkaloid-like spiroheterocycles. Recently discovered sulfur-containing [e]-fused 1H-pyrrole-2,3-diones (aroylpyrrolobenzothiazinetriones) tend to exhibit unusual reactivity. Based on these peculiar representatives of [e]-fused 1H-pyrrole-2,3-diones, we have developed an approach to an unprecedented 6/5/5/5-tetracyclic alkaloid-like spiroheterocyclic system of benzo[d]pyrrolo[3',4':2,3]pyrrolo[2,1-b]thiazole via their reaction with Schiff bases and carbodiimides. The experimental results have been supplemented with DFT computational studies. The synthesized alkaloid-like 6/5/5/5-tetracyclic compounds have been tested for their biotechnological potential as growth stimulants in the green algae Chlorella vulgaris.

Mechanistic Insights of the Ir‐bipyridonate Catalyzed Aqueous Methanol Dehydrogenation and Transfer Dehydrogenation to Acetophenone: Experimental and DFT Study

AbstractThe mechanisms of the Cp*IrIII(bpyOO)‐catalyzed (bpyOO=bidentate (NN) doubly deprotonated 2,2′‐bipyridine‐6,6′‐diol) acceptorless methanol dehydrogenation and acetophenone transfer hydrogenation by methanol under basic conditions have been explored by the combination of 1H NMR, kinetics, and DFT computational studies. During dehydrogenation of methanol and of its dehydrogenated derivatives, the presence of two iridium hydride species (anionic [Cp*Ir(bpyOO)H]−, C* and neutral [Cp*Ir(bpyOOH)H], D*), which interconvert depending on pH, was detected. The DFT studies on a Cp model system highlighted three interrelated catalytic cycles of methanol, formaldehyde and formic acid dehydrogenation, all leading to the same hydride intermediates C and D. The dehydrogenation of methanol prefers a direct β‐hydride transfer pathway from the methoxide ion to Ir, rather than the classical β‐hydride elimination pathway from a coordinated methoxide ligand, but an alternative bifunctional H+/H− transfer with involvement of a ligand O atom may become competitive at lower pH. The transfer hydrogenation of acetophenone using methanol as hydrogen source features species C* as resting state, with the acetophenone reduction being rate‐determining and following the reverse pathway of methanol oxidation, with a first‐order acetophenone decay and a kinetic isotope effect of 2.36±0.09.

Phenanthrothiophene-Triazine Star-Shaped Discotic Liquid Crystals: Synthesis, Self-Assembly, and Stimuli-Responsive Fluorescence Properties.

Lipophilic biphenylthiophene- and phenanthrothiophene-triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki-Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli-responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON-OFF switch). DFT computational studies show that intramolecular charge transfer (ICT) phenomena occurs for both molecules, and reveal that protonation enhances the electron-withdrawing ability of the triazine core and reduces the band gap. This acidochromic behavior was applied to a prototype fluorescent anti-counterfeiting device. They also specifically recognize Fe3+ through coordination, and the recognition mechanism is closely related to the photoinduced electron transfer between Fe3+ and BPTT10/CPTT10. CPTTn self-assemble into columnar rectangular (Colrec) mesophase, which can be modulated by oleic acid via the formation of a hydrogen-bonded supramolecular liquid crystal hexagonal Colhex mesophase. Finally, CPTTn also form organic gels in alkanes at low critical gel concentration (3.0 mg/mL). Therefore, these star-shaped triazine molecules possess many interesting features and thus hold great promises for information processing, liquid crystal semiconductors and organogelators.

Mechanistic insights on 1-butene polymerization catalyzed by homogeneous single-site catalysts: a DFT computational study.

Isotactic poly (1-butene) (iPB) is an interesting semi-crystalline thermoplastic material characterized by notable physical and mechanical attributes encompassing superior creep and stress resistance, elevated toughness, stiffness, and thermal endurance. These distinctive features position iPB as a viable candidate for specific applications; however, its widespread utilization is hindered by certain inherent limitations. Indeed, iPB manifests an intricate polymorphic behavior, and the gradual and spontaneous transition of the kinetically favored form II to the thermodynamically favored form I during aging introduces alterations to the material's properties. Despite its potential, the attainment of iPB with an exceedingly high molecular mass remains elusive, particularly when employing homogeneous catalysts renowned for their efficacy in propene polymerization. In this study we analyze the mechanistic aspects governing 1-butene polymerization by using DFT calculations modelling the regioselectivity of 1-butene insertions and the termination reactions occurring after primary (1,2) and secondary (2,1) insertions. Finally, the isomerization pathways leading to the formation of 4,1 units in iPB samples synthesized by homogenous catalysts is also discussed. All these aspects, furnish a mechanistic picture of the main drawbacks of an "old" but still interesting material.

Theoretical Study on the Regioselectivity of Leapfrog B18 and B30 Boron Sheets in Electrophilic and Nucleophilic Reactions Using DFT-Based Reactivity Indices.

A combined computational and interpretational DFT study is performed to investigate the regioselectivity of B18 and B30 leapfrog boron sheets upon reaction with XH3-type electrophiles and nucleophiles (X = N, P, As, B, Al). The M062X, B3LYP, and B3LYP-D3 functionals are used combined with the 6-31+G(d,p) basis. The molecular electrostatic potential (MEP), Fukui functions, and the dual descriptor are employed to predict the local reactivity of B18 and B30. Our results reveal that both clusters are hard and prefer to react with hard bases and acids, such as NH3 and BH3. Further, these leapfrog B6n clusters can play the role of catalysts as they break B-H and Al-H bonds of BH3 and AlH3 in s-BH3-B6n and s-AlH3-B6n complexes, respectively. Leapfrog B6n-XH3 complexes (X = B and Al) can be considered as an interaction between two electron-deficient systems. Therefore, the chemical reactivity between these systems cannot be interpreted in terms of the Hard-Soft-Acid-Base principle.