Molecular Orbital Structure Research Articles

Photoelectron momentum distributions of triatomic CO2 molecules by circularly polarized attosecond pulses

Abstract Molecular-frame photoelectron momentum distributions (MF-PMDs) have been studied for imaging molecular structures. We investigate the MF-PMDs of CO2 molecules exposed to circularly polarized (CP) attosecond laser pulses by solving the time-dependent Schrödinger equations based on the single-active-electron approximation frames. Results show that high-frequency photons lead to photoelectron diffraction patterns, indicating molecular orbitals, these diffraction patterns can be illustrated by the ultrafast photoionization models. However, for the driving pulses with 30 nm, a deviation between MF-PMDs and theoretically predicted results of the ultrafast photoionization models is produced because the Coulomb effect strongly influences the molecular photoionization. Meanwhile, the MF-PMDs rotates in the same direction as the helicity of driving laser pulses. Our results also demonstrate that the MF-PMDs in a CP laser pulse are the superposition of those in the parallel and perpendicular linearly polarized cases. The simulations efficiently visualize molecular orbital geometries and structures by ultrafast photoelectron imaging. Furthermore, we determine the contribution of HOMO and HOMO-1 orbitals to ionization by varying the relative phase and the ratio of these two orbitals.

Negative Differential Resistance in Single‐Molecule Junctions Based on Heteroepitaxial Spherical Au/Pt Nanogap Electrodes

AbstractSingle‐molecule junctions exploit the internal structure of molecular orbitals to construct a new class of functional quantum devices. The demonstration of negative differential resistance (NDR) in single‐molecule junctions is direct evidence of quantum mechanical tunneling through a molecular orbital. Here, a pronounced NDR effect is reported with a peak‐to‐valley ratio of 30.1 on a single‐molecule junction of π‐conjugated quinoidal‐fused oligosilole derivatives, Si2 × 2, embedded between the unique electroless gold‐plated heteroepitaxial spherical Au/Pt nanogap electrodes. This NDR feature persists in a consecutive endurance test of 180 current traces. the thermally stable NDR effects in the Si2 × 2 single‐molecule junctions between 9 and 300 K are demonstrated. The density functional theory calculations under electric fields indicate that the NDR effect can be ascribed to the bias‐dependent resonant tunneling transport via the polarized HOMO, which has asymmetrically changed electrode coupling with increased bias voltages. The results confirm a promising electrical platform for constructing functional quantum devices at the single‐molecule level.

Protic Processes in an Extended Pyrazinacene: The Case of Dihydrotetradecaazaheptacene.

Pyrazinacenes are linearly fused heteroaromatic rings, with N atoms replacing all apical CH moieties. Component rings may exist in a reduced state, having NH groups instead of N, causing cross-conjugation. These compounds have interesting optical and electronic properties, including strong fluorescence in the near-infrared region and photocatalytic properties, leading to diverse possible applications in bio-imaging and organic synthesis, as well as obvious molecular electronic uses. In this study, we investigated the behavior of seven-ring pyrazinacene 2,3,11,12-tetraphenyl-7,16-dihydro-1,4,5,6,7,8,9,12,13,14,15,16,17,18-tetradecaazaheptacene (Ph4H2N14HEPT), with an emphasis on protic processes, including oxidation, tautomerism, deprotonation, and protonation, and the species resulting from those processes. We used computational methods to optimize the structures of the different species and generate/compare molecular orbital structures. The aromaticity of the species generated by the different processes was assessed using the nucleus-independent chemical shifts, and trends in the values were associated with the different transformations of the pyrazinacene core. The computational data were compared with experimental data obtained from synthetic samples of the molecule tBu8Ph4H2N14HEPT.

SLIMP 2.0: A new version of strong laser interaction model package for atoms and molecules, now with molecular orbital tomography based on high-order harmonic spectra

A new version of strong laser interaction model package for atoms and molecules is presented. Its capacities are enhanced by incorporating modules related to molecular orbital tomography (MOT) in length and velocity forms based on high-order harmonic spectra (HHS). This advanced package enables two-dimensional and three-dimensional MOT of both symmetric and asymmetric molecules using HHS, providing an efficient means for both experimental and theoretical investigations of molecular orbital structures. In addition, it can calculate the precise theoretical orbitals corresponding to those reconstructed by MOT. Furthermore, the package can calculate the transition dipole moment (TDM) in the plane wave approximation and allow for reference MOT based on TDM. It can evaluate the quality of reconstructed orbitals based on HHS and reveal the physical and numerical effects on MOT. This package is suitable for MOT under conditions of driving laser at different intensities and wavelengths, and can be applied to different molecules with various structures. It is designed to facilitate easy expansion for additional capabilities. Program summaryProgram Title: SLIMP, version 2.0CPC Library link to program files:https://doi.org/10.17632/jgcb7m7wwv.1Licensing provisions: GPLv3Programming language: Fortran 90Journal reference of previous version: Comput. Phys. Commun. 192 (2015) 330-341.Does the new version supersede the previous version?: Yes.Reasons for the new version: Molecular orbital tomography (MOT) [1] based on high-order harmonic spectra (HHS) [2] is an important research topic in the field of strong-field physics. It provides an efficient way to probe molecular orbital structures experimentally, which was not considered in the former version of SLIMP [3] and is now included in SLIMP 2.0. The new version package allows performing two-dimensional (2D) and three-dimensional (3D) MOT [4] based on HHS obtained from experiments or simulations, providing reliable detections for many orbitals of interest, either symmetric or asymmetric molecules.Summary of revisions: Extending capacities focus on enabling performing 2D and 3D MOT on symmetric and asymmetric molecules based on HHS, and together the relevantly precise theoretical orbital output, calculation of transition dipole moment (TDM) and reference MOT based on TDM. For 2D MOT, MOT in both length and velocity forms are implemented.Nature of problem: To perform MOT based on HHS, the user needs general reconstruction programs, taking symmetric and asymmetric molecules, 2D and 3D orbitals, and MOT in length and velocity forms into account. In addition, evaluation of imaging quality is required, which can reveal the physical and numerical effects on reconstructions.Solution method: The 2D symmetric and asymmetric, length- and velocity-form, and 3D reconstruction algorithms are implemented based on Fortran 90. Furthermore, this package provides a reference MOT based on directly calculated TDM, served as a comparable result to the reconstructed orbital based on HHS. The comparison between reconstructions based on HHS and TDM can reveal the effects on MOT in physical and numerical aspects.Additional comments including restrictions and unusual features: This package does not include MOT of asymmetric molecules in velocity form. For the 2D MOT based on HHS, the reconstructed 2D projection of gerade, ungerade orbital or the gerade and ungerade components of asymmetric orbital must have the axial symmetry about the x- and z-axis. For the 3D MOT, the reconstructed 3D orbital has to be cylindrically symmetric.

Synthesis of V-shaped Thiophene Based Rotor-Stilbene: Substituent Dependent Aggregation and Photophysical Properties.

Thiophene core V-shaped rotor-stilbene derivatives have been synthesized utilizing two-fold Heck coupling reaction. These compounds are blue emitters with moderate quantum yield in dilute solution. Rotor nature of the synthesized stilbenes supports aggregation induced emission (AIE) behaviour and they show substituent dependent emission behavior in aggregate state. In presence of donating groups (e.g., tert-butyl, methoxy, diphenylamine group) in stilbenes, they exhibit AIE property. But with the introduction of electron withdrawing group (nitro group), they shows aggregation caused quenching (ACQ) behavior. Different types of nano-aggregates formation is observed in aggregated state, which was confirmed by dynamic light scattering (DLS) and scanning electron microscopy (SEM) studies. The details photophysical (absorption, fluorescence, and lifetime), electrochemical property (cyclic voltammetry) and thermal stability have been investigated. Optimized structure, energy and electronic distribution of molecular orbitals have been studied by theoretical calculation.

Synthesis and Some Electrochemical Properties of Carbazole Derivative Monomers for Optoelectronic Device Design

Low-cost instruments are used to achieve high sensitivity, accuracy and precision with electrochemical techniques, making them the most suitable analytical methods used to investigate the electrochemical properties of a new molecule. Among these techniques, cyclic voltammetry, which is widely employed, allows for the determination of electronic characteristics such as molecular energy levels and orbital structure, redox properties, sensor capabilities, surface activity, and more. The carbazole molecule can undergo derivatization from various positions, allowing for alterations in its electrical and optical properties. These compounds serve as heterocyclic building blocks that can be utilized as materials for organic sensitizers and semiconductors in optoelectronic devices. Due to the presence of a hydrogen atom in the nitrogen-hydrogen (N-H) bond within the carbazole structure, which can be replaced with different functional groups, carbazole is highly suitable for nitrogen-based derivatization studies. In this study, two different carbazole monomers (IIa and IIIa), which could be potential optoelectronic, were synthesized using the Ullman and Suzuki-Miyaura reaction and characterized using 1H NMR, 13C NMR, UV-Vis, and Flouresence spectroscopy techniques. The cyclic voltammetry experiments were performed using three different working electrodes (Au, Gc, Pt disk electrodes) for each compound. Since the optimum oxidation of the compounds was obtained from the voltammograms on the gold disk electrode, this electrode was used in the calculation of energy levels. HOMO and Eg values of the compounds were deduced from cyclic voltammetry experiments and the optical absorption bands, respectively.

Computationally engineering optoelectronic properties and photocatalytic performance in graphene quantum dot/platinum(II) complex photocatalysts

This study delves into the impact of various substituents on bipyridyl Pt(II) bisstilbenylacetylide complexes when attached to Graphene quantum dots (GQDs), a material with promising photocatalytic potential. Using density functional theory calculations, the research uncovers that the substituents significantly alter properties of the resulting nanocomposites. These include the geometric and electronic structures, optical absorption profiles, charge transfer configurations, and chemical reactivity. Electron-withdrawing groups cause blueshifts in absorption peaks, while electron-donating ones induce redshifts. These shifts are more pronounced when the complexes are attached to GQDs. The attachment of GQDs also impacts the molecular orbital structure, stabilizing the highest occupied molecular orbital (HOMO), but destabilizing the lowest unoccupied molecular orbital (LUMO). Furthermore, the incorporation of GQDs into the composite enhances overall stability while diminishing reactivity. The formation of the nanocomposite reduces the energetic favorability of electron injection and regeneration processes. Interestingly, the substituents affect the charge transfer length more significantly for nanocomposites compared to isolated complexes. Overall, this study provides valuable insights into fine-tuning optoelectronic and photocatalytic properties of GQD hybrid photocatalysts, useful in applications like solar energy conversion and pollutant degradation. These findings significantly advance the understanding of the structure–function relationship in GQD nanocomposites for photocatalysis.

Electron impact scattering and electronic excitation in glycolaldehyde: The first ever detected sugar in space

Detailed theoretical investigations on structural, spectroscopic and electron scattering cross sections of glycolaldehyde, the first ever detected sugar in space are reported in this work. Spectroscopic calculations are performed on the ground and excited states of glycolaldehyde using density functional theory (DFT) and time-dependent density functional theory (TDDFT), respectively. The optimized geometrical parameters and vibrational spectrum are in good agreement with the earlier reported work. Vertical excited state (VES) energies at the TDDFT/B3LYP/aug-cc-PVQZ level of theory along with detailed assignments are reported up to 30 transitions. The TDDFT predicted Rydberg series energies are compared with the Rydberg series of glycolaldehyde converging to its first IP, computed using the standard Rydberg formula and are found to be in good agreement. In the absence of sufficient experimental data on excited states of glycolaldehyde, the theoretical results are validated by comparison of VES calculations performed at the same level of theory with the available experimental data for an analogous molecule viz. acetaldehyde. Triplet excited-state energies for glycolaldehyde are reported here for the first time. Electron impact cross section calculations in the energy range 0.1 to 20 eV are carried out using ab-initio R-matrix method. We have detected one π* shape resonance in all the three models viz. SE, SEP and CC, which may also lead to a possible fragmentation channel wherein a hydrogen atom is removed from the molecule forming a glycolaldehyde dehydrogenated anionic radical (C2H3O2−). The π* shape resonance is correlated with the corresponding molecular orbital electronic structure calculations. Additionally, differential, electronic excitation, ionization and total cross sections are reported here for the first time.

Synthesis and investigation of nonlinear optical properties of Azo-SR8 compound using visible laser beams

The main objective of this study is to explore the properties of a chemical compound called Azo-SR8, with a focus on its synthesis, characterization, and nonlinear optical (NLO) properties. To achieve this, several methods are utilized, including 1H and 13C NMR, mass and absorption spectra, differential scanning calorimetry (DSC) thermogram, optimized structure, and investigation of frontier molecular orbitals. NLO properties of Azo-SR8 are analyzed by subjecting it to a cw 473 nm laser beam and using diffraction patterns (DPs) and Z-scan techniques to estimate the nonlinear index of refraction (NLIR) value. The compound's all-optical switching (AOS) capability is investigated using static and dynamics techniques with two cw laser beams. The obtained results provide valuable information on the potential uses of Azo-SR8 in the field of optics.

41‐3: Efficient Pure Blue Hyperfluorescence OLEDs with Donor‐Acceptor‐Donor Type Thermally Activated Delayed Fluorescence Sensitizer

In a hyperfluorescecne (HF) system, minimization of energy loss channel consisted of slow reverse intersystem crossing (RISC) and fast Dexter energy transfer (DET) is still challenging. Here, we report that such energy loss channels can minimize by utilizing quadrupolar donor‐acceptor‐donor (D‐A‐D) type TADF as sensitizer materials. We synthesized DBA‐DmICz and DBA‐DTMCz as D‐A‐D type TADF materials, which could suppress the DET process through fast RISC rate and shielded lowest unoccupied molecular orbital structure. The fabricated HF device with DBA‐DTMCz and v‐DABNA as a final dopant exhibited 43.9% of high maximum external quantum efficiency (EQEmax) with the CIE coordinates of (0.12, 0.16).

Self‐Guided Growth of Electronically Decoupled C60 on Graphene on Rh(110)

AbstractThe authors report on the behavior of C60 molecules adsorbed on graphene (Gr) monolayers grown on Rh(110), studied by means of scanning tunneling microscopy and spectroscopy under ultra‐high vacuum conditions. Fullerene molecules form a well‐ordered close packed hexagonal layout with an intermolecular distance of ≈1 nm. As demonstrated from the experimental data, the molecular packing direction of C60 is locally close to being aligned with the quasi‐1D moiré patterns formed by graphene on the metal support. Moreover, for certain orientations of graphene on Rh(110), the underlying moiré pattern appears superimposed on the molecular assembly. However, the analysis of the highest occupied molecular orbital and the lowest unoccupied molecular orbital structures and the differential conductance curves of C60 on Gr/Rh(110) suggest a weak molecule–substrate interaction, similar to other 2D material/metal interfaces. All these observations can imply that the moiré structures of Gr/Rh(110) play a central role in the arrangement of C60, but without modifying its electronic properties, which makes this Gr/Rh(110) system a singular platform for C60 adsorption. Complementarily, the structural properties of multilayer growth of C60 on Gr/Rh(110) are also investigated.

Computational and optoelectronic quantification of semi-conducting, warm ruby red color emanating Eu3+ complexes with hetro-cyclic ligands.

Six Eu3+ complexes were synthesised with β-keto acid as main ligand and secondary ligands through liquid assisted grinding method. These complexes were characterised by various techniques such as spectroscopic technique, XRD, EDAX, SEM analysis, thermal technique, Urbach energy and optical band gap investigation. The luminous photophysical properties were studied by PL spectroscopy in solid as well as solution phase and some theoretical calculation was done to investigate the radiative (Arad) & non-radiative (Anrad) transition rate, quantum efficiency (ɸ), Judd Ofelt parameters for 5D0 → 7F2,4 transitions in both states. Judd Ofelt parameters were also calculated by the JOES software and the outcomes are well harmonised with theoretical values. The complexes have CIE color coordinate value in ruby red region and above 88.65% color purity in both phases, which made them attractive candidates for red light-emitting displays. 5D0 → 7F2 transition was proposed as a laser emission transition owing to their high branching ratio (67.18-74.24%) in solid and (60.09-74.40%) in solution phase. Computational methods were employed to determine the structure and energy of various molecular orbitals. Antimicrobial assay of complexes was also rationalised and found that the complexes are pertinent as good bactericidal and fungicidal agents in pharmaceutical industry.

ДИССОЦИАТИВНЫЙ ЗАХВАТ ЭЛЕКТРОНОВ МОЛЕКУЛАМИ ДИГИДРОКУМАРИНА И 5,6-МЕТИЛЕНДИОКСИ-1-ИНДАНОНА

The molecules of dihydrocoumarin and 5,6-methylenedioxy-1-indanone were studied by the negative ion resonant electron capture mass spectrometry for slow (0-15 eV) electrons. Such studies of the structure of vacant molecular orbitals (VMO) and dissociative electron attachment (DEA) for isolated molecules of prospective organic semiconducting materials, which are of great interest in terms of use as elementary components of organic nanoelectronics devices, are the most promising, since a correspondence between the energies of vacant MO isolated molecules and the maxima of the density of states in the conduction band of thin films was revealed earlier. Also, there is an idea developing in modern science, that the results of studies of vacant orbitals of individual molecules in the gas phase, in particular, using the DEA method, are necessary to identify the features of the energy structure of the conduction band of molecular organic condensates, starting from energies below the vacuum level, by the amount of binding energy of molecules in the film. In particular, it was shown that the substances studied in this work cannot be used as monomeric compounds in the design of electrically conductive polymers in the future, since they do not form negative molecular ions in the gas phase at energies close to thermal.

Synthesis, TD-DFT, and optical properties study of a chromeno-quinoline (acceptor) and mirror-less laser action enabled by energy transfer from a conjugated-polymer (Donor)

Structurally interesting chromeno-quinolines were constructed via the cyclization reaction of O-propargylated naphthaldehyde and substituted anilines in good yields. We explored compound methyl-chromenoquinoline (MCQ) in detail for its optical properties using Time-dependent density-functional theory (TD-DFT) and experimental studies. The conjugated-polymer (CP) Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(2,5-p-xylene)] or [(ADS145UV or PFOPX)] was studied as donor. The TD-DFT implied that MCQ is a fluorescent compound with well-defined highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) structure at −5.327 eV and −1.836 eV, respectively, with an energy gap of 3.49 eV in toluene captivity. The TD-DFT-based model and experimental study showed an energy gap of 3.326 eV and 3.351 eV, respectively, and the deviation was 0.025 eV. The experimental studies of MCQ showed solvent-dependent fluorescence peak shifted from 445 ± 2 nm to 538 ± 2 nm for dielectric constant ranging from 0.01 (hexane) to 10.2 (water). Despite the good optical properties, MCQ produced a weak laser-induced fluorescence (LIF) and not produce amplified spontaneous emission (ASE) to any pump energy of 3rd harmonic from Nd:YAG laser (5 ns, 355 nm). When PFOPX of concentration 500 nM (500 μL) was added to MCQ of 506 mM (3.5 mL) concentration, the LIF suddenly improved tenfold due to efficient Fluorescence resonance energy transfer (FRET) process. At the optimal concentration of PFOPX (670 nM) in MCQ solution, the spectrum changed dramatically. The spectrum has five peaks with a LIF in the background, where peaks around 393.5 nm and 417.3 nm attribute to the oligomer; 438.7 nm attributed to a combined fluorescence of PFOPX and MCQ; 466.4 nm, and 493.1 nm corresponding to MCQ. Analysis shows that the peaks at 440 nm (partly) and 493 nm were ASE from MCQ.

Experimental and Computational Description of the Interaction of H and H- with U.

The results of ab initio correlated molecular orbital theory electronic structure calculations for low-lying electronic states are presented for UH and UH- and compared to photoelectron spectroscopy measurements. The calculations were performed at the CCSD(T)/CBS and multireference CASPT2 including spin-orbit effects by the state interacting approach levels. The ground states of UH and UH- are predicted to be 4Ι9/2 and 5Λ6, respectively. The spectroscopic parameters Te, re, ωe, ωexe, and Be were obtained, and potential energy curves were calculated for the low energy Ω states of UH. The calculated adiabatic electron affinity is 0.468 eV in excellent agreement with an experimental value of 0.462 ± 0.013 eV. The lowest vertical detachment energy was predicted to be 0.506 eV for the ground state, and the adiabatic ionization energy (IE) is predicted to be 6.116 eV. The bond dissociation energy (BDE) and heat of formation values of UH were obtained using the IE calculated at the Feller-Peterson-Dixon level. For UH, UH-, and UH+, the BDEs were predicted to be 225.5, 197.9, and 235.5 kJ/mol, respectively. The BDE for UH is predicted to be ∼20% lower in energy than that for ThH. The analysis of the natural bond orbitals shows a significant U+H- ionic component in the bond of UH.

2,2′-Bipyridine based fluorinated β-Diketonate Eu(III) complexes as red emitter for display applications

• A series of Eu(III) fluorinated β-diketonate complexes have been synthesized and characterized. • Photophysical parameters were estimated experimentally as well as theoretically via LUMPAC. • Energy of frontier molecular orbitals and global reactivity parameters were estimated. • These conductive ternary europium complexes could be utilized as red emanating materials for display applications. Synthesis and photoluminescence performance of a series of heteroleptic europium complexes with fluorinated chromophoric ligand and 2,2′-bipyridine or their derivatives as ancillary ligand are reported here. The structure of the synthesized complexes was analyzed by various spectroscopic techniques. The photoluminescence emission spectra of complexes show the existence of characteristic peaks corresponding to Eu 3+ ion attributed to 5 D 0 → 7 F J transitions. PL outcomes and color parameters have specified the red emissive nature of prepared complexes. Various photophysical parameters were estimated experimentally and theoretically from LUMPAC software. The structure and energy of various frontier molecular orbitals of the complexes were evaluated. Theoretical parameters estimated by LUMPAC corroborate with experimental data and prove the effectiveness of this method. These conducting and luminous complexes might be utilized as red light emitting materials in various display devices.

Red luminous Eu(III) complexes: Preparation, spectral, optical and theoretical evaluation

A series of luminous europium complexes were synthesized with general formula Eu(DAM)3L; DAM symbolizes diacetylmethane and L refers to the substituted 1,10-phenathroline derivatives. Results of spectral analyses affirm the binding of Eu3+ ion with DAM and heteroaromatic auxiliary units via oxygen and nitrogen atoms respectively. From Tauc’s plot, optical band gap was determined which shows the conducting behavior of synthesized complexes. Energy transfer mechanism reveals the effective sensitization of Eu3+ ion via antenna effect. Photoluminescence emission spectra have displayed most intense peak at ∼612 nm corresponding to 5D0→7F2 electric dipole transition. Synthesized ternary europium complexes exhibit red emission which is further confirmed by the position of chromaticity coordinates in CIE triangle. Structure and energy of various frontier molecular orbitals were determined computationally. These thermally stable red emissive complexes could be utilized in solid state lighting and displays.

Determination of highest occupied molecular orbital and cationic structures of cyclopentanone using high‐resolution vacuum ultraviolet mass‐analyzed threshold ionization mass spectrophotometry

AbstractThe conformational structure of cyclopentanone (CP) and the photoionization dynamics of the corresponding conformer were investigated using the high‐resolution vacuum ultraviolet mass‐analyzed threshold ionization (MATI) spectroscopic technique. To identify the conformer corresponding to the measured MATI spectrum, the potential energy surfaces associated with the twisting and carbonyl wagging motions in the S0 and D0 states were constructed at the B3LYP/cc‐pVTZ level, where the twisted conformer in both states corresponded to the global minimum. Furthermore, the Franck–Condon fitting indicated that the cationic conformer had a warped twisted C1 symmetry rather than C2 symmetry. This implies that the ionization‐induced ring distortion can be principally attributed to the removal of an electron from the highest occupied molecular orbital, which consists of the nonbonding orbital of the oxygen atom in the carbonyl group interacting with the σ orbitals in the ring of the twisted CP conformer.

Accurate redox potentials for solvents in Li‐metal batteries and assessment of density functionals

AbstractThe practical applications of Li metal batteries (LMBs) have been limited by the anodic instability which causes fatal problems including low Coulombic efficiency and short cycling lifespan. One way of addressing this issue is to develop new solvents with suitable redox potentials for electrolytes of LMBs. By using the recently developed Wuhan–Minnesota‐scaling method, the work has developed the Redox20 benchmark database consisting of the Ox10 subset of 10 oxidation potentials and the Red10 subset of 10 reduction potentials for four conventional and six fluorinated solvents in LMBs. The performances of 35 DFT methods have been assessed against Redox20. Based on the assessments, M05‐2X, M08‐HX, M08‐SO, M06‐2X, and revM06 functionals are the most accurate for the predictions of oxidation potentials, and the N12, M06‐HF, M08‐HX, HSE06, and PW6B95‐D3 functionals are best performers for calculating reduction potentials. M08‐HX gives the lowest average mean unsigned error, and it is recommended for the calculation of redox potentials. M08‐HX has been employed to calculate the redox potentials and highest occupied molecular orbital/lowest unoccupied molecular orbital structures of 48 solvents for LMBs, which is beneficial to the selection of optimal LMBs electrolyte solvents.

Novel metformin complexes: Geometry optimization, non‐isothermal kinetic parameters, DNA binding, on–off light switching and docking studies

Novel three water‐soluble chromium(III) complexes of types [Cr(Cl)(gly‐H)2(met)H2O] (1), [Cr(Cl)(met)(pro‐H)2H2O] (2) and [Cr(Cl)(his‐H)2(met)H2O] (3) (met = metformin, gly = glycine, pro = proline and his = histidine) have been synthesized. The geometrical structures have been shown to be octahedral, with substantial evidence from spectroanalytical techniques. Thermal investigations show the degradation pattern of the compounds from which the kinetic and thermodynamic parameters for the complexes' degradation were calculated using the Coats–Redfern 13 distinct kinetic models. The quantum chemical parameters were computed using the energies of the molecular orbital structures, developed from optimized geometrical structures, to evaluate the stability of the complexes. The groove binding of the complexes with CT‐DNA was confirmed by absorption and emission spectroscopy, viscosity measurements, gel electrophoresis and molecular docking studies.