LANL2DZ Basis Set Research Articles

Comprehensive Study on Synthesis, Quantum Chemical Calculations, Molecular Modeling Studies, and Cytotoxic Activities of Metal(II) Schiff Base Complexes

ABSTRACTIn this study, mononuclear Ni(II), Cu(II), Zn(II), and Pd(II) complexes of a diimine molecule (H2L) were synthesized, and their structures were elucidated by NMR, FT‐IR, UV–Vis, ICP‐OES, molar conductivity, magnetic susceptibility, and elemental analysis techniques. Stoichiometric and spectroscopic data revealed that the complexes have a metal:ligand ratio of 1:1 and the Schiff base coordinates with the metal(II) ion via nitrogen atoms of two imine groups and oxygen anions of two phenolate moieties and have a square planar geometry. The cytotoxic activity properties of the ligand and its metal complexes were screened in two distinct cancer cell lines: lung (A549) and colon (DLD‐1). The optimized molecular geometries, molecular electrostatic potential diagrams, total density of states plots, and frontier molecular orbitals of the H2L ligand and all metal(II) complexes at the ground level were calculated using density functional theory. The LANL2DZ basis set containing the effective core potentials for transition metals was used for quantum chemical calculations. The calculations supported the square planar geometry of the metal(II) ions in the complexes. The potential of all molecules to inhibit the MLK4 kinase domain (PDB ID: 4UYA) involved in cancer progression was examined by molecular docking study and the best inhibition activity belonged to the H2L molecule with a binding energy of −10.8 kcal/mol. The stability of the H2L–4UYA complex in physiological media was also confirmed by molecular dynamics simulation for 100 ns.

Structures, bonding aspects and spectroscopic parameters of morin, myricetin, and quercetin with copper/zinc complexes: DFT and TDDFT exploration.

In the present work, DFT/TDDFT techniques is used to analyze structure, bonding, reactivity and electronic transitions of quercetin, morin, myricetin with their metal (Cu and Zn) complexes. In order to comprehend metal complexes and ligands reactivity patterns, we calculated energy gaps between frontier molecular orbitals. Global reactivity characteristics, such as ionization potential, electronegativity (χ), hardness (η), softness (S), electrophilicity index (ω) electron affinity, and chemical potential (μ), were computed based on the FMO energies. Molecular electrostatic potential (MEP) maps were used to identify nucleophilic and electrophilic sites in complexes. Within the examined complexes, TDDFT and NBO analysis shed light on bonding, electronic transitions and stabilizing interactions. Ligands morin, myricetin, and quercetin exhibited higher HOMO-LUMO gap than their corresponding metal complexes, suggesting electron transfer may be faster in the metal complexes. The metal complexes displayed more negative electrostatic potentials. The absorption spectra of the ligands ranged from 258 to 360nm, whereas their complexes exhibited a broader range from 252 to 1035nm. These spectra provided important insights into charge transfer and electronic transitions, enhancing our knowledge of electronic and bonding characteristics of such compounds. G16 software is used to optimize all species. B3LYP functional was employed in combination with LanL2DZ basis set for Cu and Zn, and 6-311G(d,p) basis set for other atoms (C, H and O). Natural bond orbital examination was conducted in order to investigate interactions between the filled orbitals of one unit and empty orbitals of other unit. ORCA software was utilized to compute spectral features, incorporating ZORA method to account for relativistic effects. TDDFT studies is carried out using B3LYP functional to calculate excitation energies.

Theoretical study by DFT and TD-DFT of NLO-active push-pull molecules composed of conjugated bridges based on cyclic rings: Titanol, Ferrol, Nickelol and Zinkol.

This research is based on the theoretical study of seven push-pull molecules composed of conjugated bridges based on two different organometallic rings, these bridges are linked at their ends by acceptor groups (-NO2) and donor groups (-N(CH3)2) on the α position of the rings mentioned above. The location of the donor and acceptor groups revealed that the addition of the acceptor groups near the rings (Titanol, Ferrol and Nickelol) improves the NLO response in comparison with the grafting of these groups on the Zinkol ring and also influences the positioning of the π electrons at the level of the chromophores studied. The molecule 2B gave the highest values ​​of static first hyperpolarisabilitiy (βtot) and static second hyperpolarisabilitiy (γav), knowing that: βtot (2B) = 135.79 * 10-30 esu and γav (2B) = 135.79 * 10-35 esu. The highest values ​​of dynamic first and second hyperpolarisabilities are assigned to the molecule 1C with the following values: =1,218,310.00 * 10-30 esu and =1,324,520,000 * 10-35 esu. The metal Zn is considered as an acceptor group and the remaining metals (Ti, Fe and Ni) are considered as donor groups. The specific solvents for the seven molecules are water, ethanol and acetonitrile. The maximum wavelengths recorded for all molecules in combination with all solvents are in the range of 421.39 to 765.28nm. λ METHOD: The calculations were performed using Gaussian 16 software to perform DFT calculations with B3LYP functional. The LanL2DZ basis-set was used for transition metals, while the 6-31 + + G(d,p) basis-set was used for nonmetal atoms. The functionals used are: CAM-B3LYP, LC-wPBE, LC-BLYP, M11, wB97X, M08-HX, M06-2X, MN12SX, MN15, and M06HF. The basis-sets used are: 6-31G(d,p), 6-31 + + G(d,p), cc-pVDZ, aug-cc-pVDZ, 6-311G(d,p), 6-311 + + G(d,p), cc-pVTZ, and aug-cc-pVTZ. The Natural Bond Orbital (NBO) calculations are performed by the NBO program incorporated by default in the Gaussian 16 program. The solvation models studied are the CPCM model (conductor polarizable continuum model) and the SMD model (Solvation Model Density). Excited states calculations are calculated by the time-dependent DFT method (TD-DFT).

Design, Preparation, Characterization, Density Functional Theory, and HOMO‐LUMO Perspective of Fe3O4@SiO2‐Pr‐NH‐IC as a New Nanomagnetic Chemosensor

ABSTRACTIn this research, the Fe3O4@SiO2‐Pr‐NH‐IC magnetic nanoparticles (MNPs) were synthesized based on Fe3O4 nanoparticles. Initially, Fe3O4 was coated with tetraethylorthosilicate (TEOS) to produce Fe3O4@SiO2, which was functionalized by the reaction with 3‐aminopropyl three‐methoxy silane (APTMS) to yield Fe3O4@SiO2‐Pr‐NH2, followed by the treatment with indole‐3‐carbaldehyde (IC) to obtain Fe3O4@SiO2‐Pr‐NH‐IC as target hybrid organic and inorganic material. The Fe3O4@SiO2‐Pr‐NH‐IC was analyzed using photoluminescence spectroscopy. It was shown that this compound can selectively detect Al3+ ions in aqueous media among various cations, with a limit of detection (LOD) of 2.47 × 10−6 M. Comprehensive DFT calculations were carried out utilizing the B3LYP functional in conjunction with the 6‐311g (d,p) and LANL2DZ basis sets to analyze the ground state of the system. To elucidate the interaction mechanism, the MEP map was generated, and a full geometry optimization was performed. Additionally, the electronic properties and chemical reactivity were examined through a HOMO‐LUMO analysis at the same computational level. The findings revealed that the incorporation of the Al3+ ion significantly enhances the reactivity of the Pr‐NH‐IC + Al3+ complex in comparison to the free Pr‐NH‐IC structure. These findings suggest that Fe3O4@SiO2‐Pr‐NH‐IC has significant potential for the development of advanced sensor systems for the selective detection of Al3+ ions in aqueous environments. Future research could focus on the modification of the nanostructure to enhance its sensitivity and selectivity toward other environmentally and biologically relevant metal ions. Additionally, the integration of this material into portable sensing devices or the development of a real‐time detection system could pave the way for practical applications in environmental monitoring and water quality assessment.

Electronic, structural and nonlinear optical investigation of manganese carbonyl complexes of isatin derivatives by DFT.

Isatin-Schiff bases have wide applications in chemistry. The π conjugated electronic system and heterocylic structure of these materials make them valuable for use as photosensitized materials. The delocalization of π-electrons throughout the structure causes the UV-vis absorption spectra to shift to longer wavelengths. In this study, the isatin manganese carbonyl complex shifted the UV-vis absorption wavelength to a longer wavelength (vis. 400-700nm) compared with our previous studies. The isatin derivatives (ISE (3[4-ethyl(phenyl)imino][indoline-2-one]), ISB (3[4-butly(phenyl)imino][indoline-2-one])) and their Mn carbonyl complexes MnISE ((ISE)Mn(CO)3), and, MnISB ((ISB)Mn(CO)3) were investigated via density functional theory (DFT) in different solvent media. The most stable complexes were found in medium polarity THF. The calculated HOMO-LUMO energy gap shows that the charge transfer occurs within the molecule. The HOMO-LUMO energy gap was increased with increasing solvent polarity for all investigated compounds. The smaller energy gap indicates that charge transfer occurs within the Mn(II) complex, in contrast to ISE and ISB, which exhibit larger energy gaps. As a result, the maximum absorption of Mn complexes shifts to the visible region. MnISB has the smallest HOMO-LUMO energy gap in THF. Additionally, the global reactivity parameters indicated that the MnISE complex has the highest electrophilicity index. DFT calculations have also been performed to investigate polarizability and first-order hyperpolarizability of these compounds. In water, the ISE had higher NLO values than the other structures did. These results indicate that all the studied molecules in different solvents could be good candidates for use in photosensitized and nonlinear optical materials. Geometries were determined at the DFT level via the LANL2DZ basis set for Mn and cc-PVTZ for other atoms in the molecules with the B3LYP functional. The UV-vis absorption spectra and HOMO-LUMO energies of ISE, ISB, and their Mn complexes were calculated by Time-dependent DFT (TDDFT) with CAM-B3LYP using the same basis sets. The UV-vis absorption spectra of ISE were also measured in acetonitrile and compared with the calculated spectra, which were consistent with the experimental results. All calculations were repeated in different solvents with the polarizable continuum model (PCM).

Crystal structure, DFT and Hirshfeld surface analysis of acylpyrazolone based square pyramidal Cu(II) complex: In-vitro anticancer activity

This study reports the synthesis and comprehensive characterization of a novel Cu(II) complex, [Cu(HL)2(DMSO)], featuring an acylpyrazolone ligand known for its strong σ-donating capability. Extensive structural and spectroscopic analyses were conducted to elucidate the complex’s properties and potential applications. Single-crystal X-ray diffraction revealed that the complex adopts a square pyramidal geometry, with the central copper ion coordinated by four oxygen atoms from the acylpyrazolone ligand in a bischelating arrangement, involving both carbonyl and benzoyl carbonyl oxygen atoms. An oxygen atom from a DMSO molecule occupies the apical position, providing additional stabilization. The complex crystallizes in the monoclinic crystal system with the P21/c space group, offering insights into the ligand arrangement around the copper centre and the electronic environment of the complex. To further support and validate experimental findings, DFT calculations were performed using the B3LYP functional and the LANL2DZ basis set. The optimized geometries showed strong alignment with the experimental structural data. The synthesized complex was characterized through FTIR, UV–Vis, TGA, elemental analysis and cyclic voltammetry techniques, each contributing detailed insights into the complex’s electronic structure, thermal behaviour and redox properties. Hirshfeld surface analysis was also employed to examine intermolecular and non-covalent interactions within the crystal lattice. Biological evaluation included in vitro cytotoxicity assays against SH-SY5Y (neuroblastoma) cells, where the complex demonstrated significant cytotoxicity, effectively inducing cell death. Comparison with cisplatin, a well-known anticancer drug, revealed that the synthesized compound exhibited superior anticancer activity, underscoring its potential as a more effective therapeutic agent in cancer treatment.

An Integrated Experimental-Theoretical Study on the Role of Additives in the Acid Electrodeposition of Copper

Copper electroplating plays a critical role in the field of industrial processes. Copper is among the most common electrodeposited layers in both technological and decorative applications. Moreover, copper electroplating is a key step to avoid nickel layers, in fact, there is a growing trend toward Ni-free production process due to concerns about the toxicity of Ni [1,2].Common copper electroplating solutions typically consist of CuSO4, H2SO4, NaCl, and different organic additives named suppressor, brightener, and leveller [3,4]. These types of additives are crucial for achieving shiny and adherent deposits but despite their widespread use, the mechanisms of action remain unclear. Understanding the influence of additives is important both to improve the quality of deposits and to meet environmental sustainability goals, including reducing organic pollutants in wastewater and replacing toxic additives like thiourea with eco-friendly alternatives such as L-cysteine. In this context, a comprehensive analysis using an integrated experimental and theoretical approach can provide significant benefits.In this study, Electrochemical techniques and computational methods were used to elucidate the mechanisms behind the use of additives in industrial copper electroplating. Classical molecular dynamics simulations, following the gaff2016 protocol, were performed to study the behaviour of electrolytes under an electric field and assess the possibility of physical absorption. Additionally, ab-initio calculations using CAM-B3LYP(D3BJ) and a mixed 6-31G(d,p)-LANL2DZ basis set were employed to investigate the possibility of a chemical absorption and explain how additives influence the directional growth of copper nuclei.The theoretical results obtained were verified experimentally by performing electrochemical depositions of copper under different conditions. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to study the surface composition and provided information on the nature of adsorption (chemical or physical) of additives on the copper surface. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used to investigate the effect of additives on the morphology of the deposits, including grain size and roughness. Finally, X-ray diffractometry (XRD), SEM, and AFM imaging helped quantify preferential orientation caused by additives and revealed the influence in the initial growth steps, identifying a pivotal 2D structure. The innovatively interdisciplinary approach based on the integration of experimental and theoretical used in this work made the understanding of electrodeposition processes more clear, paving the way for sustainable and efficient electrochemical manufacturing practices.

Quantum chemical modeling of the structure and stability of hydrated and sulfated stannic acid complexes

Various H2SnO3 complexes and their hydrated and sulfated derivatives are calculated within the framework of the cluster approximation with the B3LYP, ωB97XD DFT functionals and the LanL2DZ(Sn), 6-31G**(O,S,H) and DGDZVP basis sets, and taking into account periodic boundary conditions with the PBE functional and the basis of the projector-augmented plane waves PAW. It was found that among the considered hydrated forms, the most energetically preferred are nanostructures in the form of ultrathin bars with a Sn2O2 cross section of the composition SnO2/1.5H2O and SnO2/2H2O. For sulfated complexes, two types of structures can be formed: with H2SO4 molecules adsorbed onto the surface of the hydrate shell around SnO2, and more stable structures with SO42− anions directly bound to Sn atoms on the surface of the tin oxide backbone.

A new luminescent material based on bismuth(III): Synthesis, structural characterization, DFT calculations, Hirshfeld surface, thermal behavior, vibrational and optical properties

Bismuth-halide-based hybrid materials are desirable in luminescent applications due to low toxicity and chemical stability. (C8H12N)4Bi2Cl10, was elaborated by the slow evaporation technique at room temperature. Single-crystal X-ray diffraction analysis indicates that the compound belongs to the monoclinic crystal system with the centrosymmetric space group P21/c. The formula unit comprises four protonated organic cations (C8H12N)4+, one [Bi2Cl10]4− dimer. The organic layers are inserted between the inorganic ones and connected with N-H…Cl and C-H…Cl hydrogen bonds to build a three dimensional network. The infrared IR and Raman studies which were recorded at room temperature in the 500–4000 cm−1 and 50–4000 cm−1 frequency regions, respectively, confirmed the existence of vibrational modes that correspond to the organic and inorganic groups. The optimized molecular structure and vibrational frequencies were calculated by the Density Functional Theory (DFT) method using the B3LYP level employing level employing a LANL2DZbasis set. It shows a good agreement between the calculated and the experimental vibrational frequencies. Hirshfeld surface analysis of close intermolecular interactions in this compound enables the identification and examination of molecular shapes. The crystal exhibits thermal stability up to 160 °C using the Thermogravimetric analysis TGA. The optical properties were characterized experimentally by UV–visible absorption studies and photoluminescence measurements. The Photoluminescence spectrum shows a green luminescence peak which is attributed to excitonic emissions within the chlorobismuthate octahedron. HOMO-LUMO orbital energies were studied by using DFT calculations.

Structural, spectroscopic, and biological properties of an asymmetric Cu (II) Schiff-base complex: Synthesis, DNA/BSA interactions, and antimicrobial potential with experimental and computational insights

A copper (II) complex with the asymmetric bidentate Schiff-base ligand (E)-2-(((4-chlorophenyl) imino) methyl) phenol was synthesized and characterized using FTIR and UV–VIS spectroscopy. Photoluminescence studies were conducted on both the copper (II) complex and the free ligand. XRD analysis revealed the copper (II) complex crystallizes in the monoclinic system, space group P21/c. The complex structure was optimized using DFT calculations with B3LYP/6-31G+(d,p) and Lanl2dz basis sets, with QTAIM and NBO analyses confirming complex formation. The energy gap of the copper (II) complex was determined to be 3.701 eV (alpha state) and 2.764 eV (beta state). MEP analysis of the optimized structure indicated a hydrophobic environment around the nitrogen atom, with the molecule exhibiting overall hydrophobicity. The chlorine atoms were identified as potential nucleophilic sites. The antimicrobial efficacy of a Schiff base copper (II) complex was evaluated against selected pathogenic bacteria (B. subtilis, B. megaterum, K. pneumoniae, E. coli) and the fungus Candida albicans. Among these C. albicans for complex showed larger zones (11–15.5 mm) at higher concentrations such as 2 and 2.5 mg/mL. Molecular docking studies suggested strong binding affinity between the complex and the target protein, this was further supported by obtained root means square deviations, root means square fluctuations, radius of gyration and hydrogen bond values during simulations. The binding free energy between BSA and the copper (II) complex was calculated as −8.7 kcal/mol, indicating significant interaction. However, only weak van der Waals interactions were observed between the complex and DNA. Toxicity studies revealed the copper (II) complex had minimal irritant effects on ocular and cutaneous tissues, with a low lethal dose. In comparison, Tricresyl phosphate showed moderate to severe ocular irritancy and modest cutaneous irritancy.

STUDY ON GEOMETRICAL STRUCTURES AND ABSORPTION SPECTRA OF M\(_4\)\(^{2+}\) CLUSTERS (M = Cu, Ag, Au) ENCAPSULATED IN SAPO-42 ZEOLITE \(\beta\)-CAGE USING DENSITY FUNCTIONAL THEORY

The most stable structures of tetrahedral M42+ cluster (M = Cu, Ag, Au) encapsulated in SAPO-42 zeolite \(\beta\)-cage have been determined by the DFT method using a/the B3LYP functional and LANL2DZ basis set. Electronic energies, zero point correction to energies and geometries, as well as the charge of the clusters, have been derived accordingly. The results showed that while the Cu-Cu bond length increases much when Cu42+ is in the framework, the Ag-Ag and Au-Au distances do not. The UV-Vis spectra of the [M4@SAPO-42]2+ clusters, which were calculated at the same hybrid B3LYP functional and the LANL2DZ basis set, show strong absorption peaks at 259 nm, 270 nm, and 259 nm for M being Cu, Ag, and Au, respectively. The nature of electronic transitions that are responsible for the absorption peaks in the UV-Vis spectrum of the [M4-SAPO-42]2+ clusters has been revealed.

Theoretical Study of Structure and Acidity of Uric Acid and its Metal Complexes: M(UA)+n (M= Li+, Be++, Na+, Mg++, K+, Ca++) and M(UA)2+n (M= Zn+2, Cd+2, Cu+, Ag+)

Uric acid (UA) is a biological molecule which is susceptible to be investigated theoretically. A theoretical investigation is carried out in the gas phase and by water effect at the ground state by using density functional theory method (DFT) at the B3LYP/6-31(d) and B3LYP/ LANL2DZ levels on the structure of different chemical forms of Uric Acid (UA) and its metal complexes. Solvent effect (water) is included using the polarizable continuum model (PCM). Neutral structures (ketonic, enolic, dimeric, monohydrate) and anionic structures has been fully optimized. Furthermore, and in order to estimate the Brönsted acidity of (UA), the interaction of both enolic and ketonic forms with alkali meta cations (Li+, Na+, K+, Be++, Mg++, Ca++) was calculated in M(UA)+n complex structures. Proton acidity of (UA) and its complexes was estimated by calculating deprotonation energy (DE) and δ (ppm)11H NMR chemical shift using GIAO method. Metal cations effects on distinct N-H and O-H stretching vibrational modes of studied structures have also been examined. Further, we explored the geometry, and acidity of several uric acid transition metal complexes M(UA)2+n (M= Zn+2, Cd+2, Ag+, Cu+) in water. The complex was calculated using mixed basis set 6-31G(d) and LANL2DZ (on the transition metal).

Structural and energetic properties of cluster models of anatase-supported single late transition metal atoms: a density functional theory benchmark study.

Single-atom catalytic systems constitute an intriguing research topic due to their inherently different chemical behavior as compared to classic heterogeneous catalysts. In this study, cluster systems representing single late transition metal atoms adsorbed on anatase were constructed starting from previously generated periodic models and subjected to a density functional theory (DFT) benchmark study. The ability of different density functional approximations representing all rungs of the Jacob's Ladder classification to accurately describe bond lengths and adsorption energies was assessed for these clusters with the aim of revealing the functional that allows to retain the structural characteristics of the initial periodic system, while also delivering reliable energetics. In this regard, our results indicate that optimisation of the clusters with the meta-GGA functionals TPSS or RevTPSS provides the lowest mean unsigned error and root-mean-square deviations with respect to the periodic models. Moreover, these functionals and, to a slightly lesser degree, PW91 were also found to provide adsorption energies that are statistically the least deviating from the CCSD(T) reference data. More complex hybrid functionals appear to be performing less well. Cluster geometries were determined at the Kohn-Sham DFT level using the LANL2DZ basis set for the transition metals and the Pople 6-31G(d) basis set for O and H. The density functional approximations considered were SVWN, PBE, BP86, BLYP, PW91, TPSS, RevTPSS, M06L, M11L, B3LYP, PBE0, M06, M06-2X, MN15, ωB97X-D, CAM-B3LYP, M11, and MN12-SX. Reference adsorption energies of the metals on the support cluster were obtained at the CCSD(T)/LANL2TZ (transition metals)/6-311 + + G(d,p)//RevTPSS/LANLD2DZ (transition metals)/6-31G*. Besides the above-mentioned functionals, energy calculations using the double-hybrid functionals, DSDPBEP86, PBE0-DH, and B2PLYP, were also performed. All adsorption energy calculations were carried out on the RevTPSS geometries.

Investigation of pivalic acid-derived organotin(IV) carboxylates: Synthesis, structural insights, interaction with biomolecules, and computational studies

Herein, six homoleptic and heteroleptic tri-organotin(IV) complexes (1–6) of pivalic acid (HL) were synthesized using 2,2′-bipyridine (bipy) and organotin(IV) chlorides, with a general formula of R3SnL/R3SnLbipy, where R = CH3, C4H9, and C6H5. The structure of the complexes was established in the solid phase via FT-IR spectroscopy and in solution through multinuclear NMR spectroscopy. The variety of coordination modes was implemented by the carboxylate group of pivalic acid, which is reflected in the FT-IR data and also supported by the single crystal XRD analysis for complex 5. The single crystal data revealed the presence of a five-coordinated distorted trigonal bipyramidal geometry for complex 5. The structural and electronic details of the complexes were also evaluated by the application of density functional theory through the Lanl2DZ basis set. The ability of complexes to inhibit the AChE and BChE was assessed in vitro as well as theoretically through molecular docking studies and the results were promising. The complexes 4 and 5 showed high inhibitory potency and could be a potential drug candidate. The DNA binding mode of the complexes was studied using UV–Vis spectroscopy and cyclic voltammetry. The findings revealed that these complexes readily intercalate into DNA via a spontaneous process. Additionally, an effective binding of the complexes with surfactant cetyl trimethyl ammonium bromide (CTAB) through a spontaneous process also proved them valuable in pharmacology.

Molecular design and characterization of the PANI/yttrium oxide multifunctional nanocomposite material

A detailed density functional theory study was conducted on the nanocomposites formed by polyaniline and yttrium oxide clusters, employing the mixed 6-311G(d,p)/LANL2DZ basis set. The investigation identified the formation of the nanocomposites through strong covalent bonding and moderate electrostatic interactions, resulting in significant binding energies. These interactions contributed to a reduction in the band gap, increased electron activity, and higher chemical reactivity compared to pure polyaniline. The formation of the nanocomposites induced a redshift in the UV–vis absorption spectra, moving the maximum absorption wavelength from the ultraviolet to the visible region, indicating n-type doping. Natural bond orbital analysis confirmed the role of yttrium oxide clusters as electron acceptors, with polyaniline serving as an electron donor.

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 .

Mongrel synthesis of tin (IV) based 3-aminopyridine with hydrogen halides: Structural, optical, thermal analysis, DFT, Hirshfeld surface analysis and antibacterial investigations

The novel organic-inorganic hybrid materials (C5H7N4)2 [SnCl6] 2- (1) and (C5H7N4)2 [SnBr6]2-(2) have been synthesized and characterized by single-crystal X-ray diffraction at room temperature. Both compounds demonstrate the crystal system was triclinic with Pī space group. Hirshfeld surface analysis investigate the intermolecular interactions and crystal packing derived by single-crystal XRD data reveals the closer contacts associated with strong interactions. Infrared spectrum of both compounds shows the NH stretching band at 3396 cm−1 which indicates a protonated amine group. The product crystals optical characteristics were inspected using UV–visible and photoluminescence spectroscopy. The thermal characteristics were evaluated simultaneously using thermogravimetric (TG) and differential thermal analysis. Tin formal oxidation state was determined as +4 through bond valence sum calculations and CSM shows the ideal octahedral geometry of the anions. DFT calculations utilizing the B3LYP method with the LanL2DZ basis set provide optimized geometries and molecular electrostatic potential maps. We explored the energy difference between (HOMO) and (LUMO) orbitals to understand molecular electrical transport capabilities. The biological activity of the investigated compounds are examined against pathogens which indicates efficacy against bacterial strains.

Theoretical investigation of norfloxacin hybrid compounds with silver, copper, and gold metals as potential anticancer agents

The strategy of drug repurposing and repositioning in developing hybrid molecules is significant in drug discovery. Norfloxacin (Nor) hybrids, part of the fluoroquinolone class of antibiotics, have demonstrated anticancer properties. Various norfloxacin metal complexes have been synthesized and evaluated for their anticancer potential through docking simulations using AutoDock Vina. To preliminarily identify potential molecular targets for these anticancer compounds, docking studies were conducted with a variety of enzymes and receptor proteins associated with the cell cycle, cell growth, and DNA replication. These targets included cyclin dependent protein kinase-2 (CDK-2), CDK-6, DNA topoisomerases I and II, B cell lymphoma-2 (Bcl-2), and vascular endothelial growth factor receptor-2 (VEGFR-2). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were conducted utilizing the B3LYP functional with the 6-311G++ and LanL2DZ basis sets. This study investigated the optimized geometries, molecular electrostatic potential (MEP) maps, key molecular properties, and HOMO-LUMO energy gaps of Nor, Nor zwitterionic structure, and its synthesized compounds ([Ag2(Nor)2](NO3)2, [Cu(Nor)2(H2O)2]SO4.5H2O, and [Au(Nor)2(H2O)2]Cl3). KEY WORDS: Norfloxacin, Anticancer agents, DFT/ TD-DFT, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1775-1790. DOI: https://dx.doi.org/10.4314/bcse.v38i6.21

Theoretical investigation of complexes of uranyl(II), vanadyl(II) and zirconyl(II) with vitamin B13 as candidate compounds as anti-nonalcoholic fatty liver disease and Diabetes mellitus targets

Density functional theory (DFT) calculations were carried out utilizing the B3LYP functional in conjunction with the 6-311G++ and LanL2DZ basis sets to explore the molecular properties and geometries of Vitamin (Vit) B13 and its complexes with Uranyl (II), Vanadyl (II), and Zirconyl (II). The optimized structures, molecular electrostatic potential maps, key molecular properties, and HOMO-LUMO energy gaps of these compounds were systematically examined to gain insights into their electronic characteristics and stability. Bioactivity screenings of the synthesized complexes were performed using molecular docking studies to investigate their interactions with diabetes mellitus (DM) target proteins, specifically the Insulin Receptor (IR) (PDB ID: 1IR3) and the peroxisome proliferator-activated receptor-γ (PPARγ) (PDB ID: 3K8S). These receptors play pivotal roles in the PPAR and AMP-activated protein kinase (AMPK) signaling pathways, which are essential for protecting against nonalcoholic fatty liver disease (NAFLD). The docking results highlighted the binding affinities and potential bioactivity of Vit B13 and its metal complexes, suggesting their promise as therapeutic agents against DM and NAFLD. This comprehensive computational study provides valuable insights into the molecular interactions and electronic properties of these compounds, paving the way for further experimental validation and potential pharmaceutical applications. KEY WORDS: Vitamin B13, Metal complexes, Diabetes mellitus, Molecular docking, DFT Bull. Chem. Soc. Ethiop. 2024, 38(6), 1743-1757. DOI: https://dx.doi.org/10.4314/bcse.v38i6.19

Theoretical insight on electronic and optical properties of some phosphorescent iridium(III) complexes for organic light-emitting diode devices

Organic light-emitting diode (OLED) structures have been extensively investigated because of their potential applications in various fields. It is known that organic or metal-mediated organic compounds are used in the layers of OLEDs. Within OLED materials, iridium(III) compounds have attract much attention owing to their many advantages. Therefore, we predicted the OLED behaviors of twenty-five phosphorescent iridium(III) complexes using theoretical chemical methods. All theoretical calculations were performed with the B3LYP hybrid functional using Gaussian 16 and Amsterdam Modeling Suite 2023 programs. While the 6–31G(d) basis set for non-metal atoms and LANL2DZ basis set for iridium metal was preferred in the computations carried out by using Gaussian program, whereas in the calculations performed with the Amsterdam Modelling Suite program, the TZP basis set was used for all atoms. From the theoretically obtained results, it is seen that Ir6, Ir7, Ir22-Ir25 complexes can be proposed as good candidate for hole injection layer materials in OLED based on indium tin oxide as an anode. Within complexes investigated, it has been determined that Ir16 and Ir17 complexes are the most suitable candidates for electron transport layer materials, whereas Ir16 complex can be used as both a hole transfer layer and ambipolar materials. Furthermore, it has been predicted that Ir4, Ir7, Ir8, and Ir23 complexes could be preferred as hole blocking layer compounds. From the detailed analysis of the singlet-triplet transitions of the complexes studied, it could be said that all iridium(III) complexes investigated could be used as highly efficient phosphorescent OLED molecules.