Electron Localization Function Calculations Research Articles

Influence of external electric field on properties of Cyclotriparaphenyl[6]carbon

Cyclotriparaphenyl[6]carbon is a hypothetical derivative compound of cyclo[12]carbon, in which three CC triple bonds are replaced by three benzene rings. Comprehensive investigations of influence of external electric field (EEF) on cyclotriparaphenyl[6]carbon have been performed from theoretical aspect in this work. The maximum appropriate applied electric field strength is 0.0265 a.u., electron detachment will occur when EEF exceeds this value. When the EEF is in the range of 0–0.0265 a.u., with the increase of EEF, the shape of cyclotriparaphenyl[6]carbon turns from a circle to oval, the HOMO-LUMO gap gradually decreases from 6.046 eV at 0 a.u. to 2.322 eV at 0.0265 a.u., and its absorption band extends to VL (visible light) region and near-infrared region little by little. When the EEF are 0.025 a.u. and 0.0265 a.u., its maximum absorption wavelengths are 1220.6 nm and 1383.5 nm, respectively. HOMA (Harmonic oscillator measure of aromaticity), AV1245 and electron localization function (ELF) calculation results indicate that cyclotriparaphenyl[6]carbon has no aromaticity in the EEF range of 0–0.0265 a.u.. The compound exhibitspromising potential forapplication inthefield of colordevelopingcompound materials.

The geometry, electronic and magnetic properties of Zr n Ni (n = 2-14) clusters: A first-principles jointed particle-swarm-optimization investigation

Zirconium-nickel binary alloys and metal glass have superior performance like ultrahigh fracture strength, good toughness. In this paper, the structures of small-sized Zr n Ni (n = 2–14) clusters have been searched using the particle swarm algorithm in combination with density-functional theory (DFT). The geometrical configuration tends to form a three-dimensional structure as the number of atoms in the cluster increases. By calculating the average binding energy per atom, second-order difference of energy, and dissociation energy of Zr n Ni (n = 2–14) clusters, it is demonstrated that Zr n Ni (n = 7, 12) clusters are more stable than their neighbors, and can be used as a candidate structure for magic number clusters. The electron localization function (ELF) calculations reveal those metallic bonds of Zr-Ni and Zr-Zr atoms. The Adaptive natural density partitioning results show that there are 20 three-center and 7 seven-center two-electron orbitals which make the quenching of magnetic moments of Zr12Ni atoms.

Bandgap engineering and antiferroelectric stability of tantalum doped silver niobate ceramics from first-principles

Extensive research has been conducted on silver niobite (AgNbO3)-based antiferroelectric ceramics for their promising applications in energy storage applications, with various compositional modifications explored to improve their energy storage capabilities. In this theoretical study, we have systematically investigated the electronic, structural, and chemical bonding properties of AgNb1-xTaxO3 (x = 0.00, 0.125, 0.25, 0.375, 0.50, abbreviated as ANT100x) solid solutions based on first-principles calculation. Our results reveal that the bandgap increases from 1.82 eV to 1.89 eV, due to the higher energy level of Ta 5d orbitals compared to Nb 4d orbitals. The enlarged bandgap, accompanied with oxygen vacancy formation energy (ΔEf,vac), contributes to the enhancement of Eb. The Ta substitution of Nb site suppresses the cation displacement, oxygen octahedral distortion, and bond length and angles, indicating an improved stability of antiferroelectric phase. In addition, the electron localization function (ELF) and Bader charge values show weakened covalent bonding of Ta−O bonds compared to Nb−O bonds. These theoretical findings have the potential to aid in the advancement and creation of novel energy storage applications using lead-free AFE perovskites, as well as facilitate the manipulation of their breakdown electric field through bandgap engineering.

Theoretical study of the structural and thermodynamic properties of U-He compounds under high pressure.

Uranium is considered as a very important nuclear energy material because of the huge amount of energy it releases. As the main product of the spontaneous decay of uranium, it is difficult for helium to react with uranium because of its chemical inertness. Therefore, bubbles will be formed inside uranium, which could greatly reduce the performance of uranium or cause safety problems. Additionally, nuclear materials are usually operated in an environment of high-temperature and high-pressure, so it is necessary to figure out the exact state of helium inside uranium under extreme conditions. Here, we explored the structural stability of the U-He system under high pressure and high temperature by using density functional theory calculations. Two metastable phases are found between 50 and 400 GPa: U4He with space group Fmmm and U6He with space group P1̄. Both are metallic and adopt layered structures. Electron localization function calculation combined with charge density difference analysis indicates that there are covalent bonds between U and U atoms in both Fmmm-U4He and P1̄-U6He. Regarding the elastic modulus of α-U, the addition of helium has certain influence on the mechanical properties of uranium. Besides, first-principles molecular dynamics simulations were carried out to study the dynamical behavior of Fmmm-U4He and P1̄-U6He at high-temperature. It was found that Fmmm-U4He and P1̄-U6He undergo one-dimensional superionic phase transitions at 150 GPa. Our study revealed the exotic structure of U-He compounds beyond the formation of bubbles under high-pressure and high-temperature, which might be relevant to the performance and safety issues of nuclear materials under extreme conditions.

Superhard lithium carbaboride clathrates

Lightweight strong boron-carbon clathrates adopting sodalite structure have been inspirated by the successful synthesis of the SrB3C3 compounds, which assuming the cubic bipartite sodalite structure. In this work, we designed series of stoichiometric LiBxC12-x and Li2BxC12-x (x = 1–6) compounds based on boron substitution of carbon in carbon sodalite structure using first-principles calculations. We found that LiB2C10, LiB3C9, LiB4C8, Li2B3C9 and Li2B4C8 are dynamically stable at high pressure and can be recovered under normal pressure. Strikingly, compared with inserting one Li atom into the B-C framework, inserting two Li atoms exhibit lower enthalpy value and better symmetry. Li2B4C8 is identified as the most stable structure among these compounds, and Li2B4C8 could potentially be synthesized at moderate pressure. The electron localization function calculations reveal that there is a strong covalent bond between B and C atoms in the clathrates, which forming the rigid three - dimensional crystalline networks. Moreover, the estimated Vickers hardness values of these five stable clathrates are 42 ∼ 51 GPa, which can be classified as superhard materials. At the same time, the pure shear strength of LiB2C10 is found to be 48.1 GPa, which exceeds the threshold value of 40 GPa. The pure shear strength of LiB3C9 (38.0 GPa) and Li2B3C9 (38.8 GPa) are found to be close to 40 GPa. Our work presents a new strategy for exploring superhard sodalite-like clathrate candidates.

Ab initio prediction of half-metallicity, stability and reconstruction in Cu3TaTe4 (1 0 0) surface

This study reports DFT calculations on structural stability, electronic and magnetic properties of Cu3TaTe4(100) surface. Four possible symmetric terminations such as CuCu, CuTa, TeTe(1), and TeTe(2) are considered in cleaving the bulk crystal along (100) plane to form surface slab models. Surface energy calculation predicts that surface slab with CuCu termination is most stable and CuTa termination is most unstable. Meanwhile, the structural parameters after relaxation indicate that TeTe(2) surface could be most unstable due to its outward relaxation. Electron Localization Function calculations have shown that this seemingly contradicting results could be due to surface reconstruction in TeTe(2) surface, which significantly lowers the energy of the system. Electronic band structures of Cu3TaTe4(100) surface slabs exhibit transition from semiconducting nature in bulk crystal to either half metallic or fully metallic nature depending on the termination. The half metallic nature in CuCu and CuTa surface terminations provide promising theoretical data for future development of spintronic device.

Yb Substitution and Ultralow Thermal Conductivity of the Ca3–xYbxAlSb3 (0 ≤ x ≤ 0.81(1)) System

A series of Yb-substituted Zintl phases in the Ca3-xYbxAlSb3 (0 ≤ x ≤ 0.81(1)) system has been synthesized by initial arc melting and post-heat treatment, and their isotypic crystal structures were characterized by both powder and single crystal X-ray diffraction analysis. All four title compounds adopted the Ca3AlAs3-type structure (space group Pnma, Pearson code oP28, Z = 4). The overall structure can be described as a combination of the 1-dimensional (1D) infinite chain of ∞1[Al(Sb2Sb2/2)] formed by two vertices sharing [AlSb4] tetrahedral moieties and three Ca2+/Yb2+ mixed sites located in between these 1D chains. The charge balance and the resultant independency of the 1D chains in the title system were explained by the Zintl-Klemm formalism [Ca2+/Yb2+]3[(4b-Al1-)(1b-Sb2-)2(2b-Sb1-)2/2]. A series of DFT calculations proved that (1) the band overlap between the d-orbital states from two types of cations and the p-orbital states from Sb at the high symmetry Γ point implied a heavily doped degenerate semiconducting behavior of the quaternary Ca2YbAlSb3 model and (2) the site preference of Yb for the M1 site was due to the electronic-factor criterion based on the Q values of each atomic site. The electron localization function calculations also proved that the two different shapes of lone pairs of the Sb atoms─the "umbrella-shape" and the "C-shape"─are determined by local geometry and the coordination environment on the anionic frameworks. Thermoelectric measurements of the quaternary title compound Ca2.19(1)Yb0.81AlSb3 showed an approximately two times larger ZT value than that of ternary Ca3AlSb3 at 623 K due to increased electrical conductivity and ultralow thermal conductivity originated from Yb substitution for Ca.

Cu4TiTe4: Synthesis, Crystal Structure, and Chemical Bonding.

A new compound Cu4TiTe4 in the Cu-Ti-Te ternary system is prepared using high-temperature solid-state synthesis and characterized by single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy. The average structure of Cu4TiTe4 crystallizes in the cubic space group P4̅3m (cP9; a = 5.9484(1) Å) and adopts the Cu4TiSe4 structure type. Like Cu4TiSe4, it shows positional disorder in one of the two Cu sites. The three-dimensional structure of Cu4TiTe4 is viewed as a cubic close-packed (ccp) array of Te, where half of the tetrahedral holes are orderly occupied by three Cu and one Ti and the disordered Cu atoms effectively occupied 1/4 of the octahedral holes. The calculated density of states (DOS) discerns that the compound is a narrow-bandgap semiconductor, and the crystal orbital Hamilton population (COHP) analysis shows that though the individual Cu-Te short contact is relatively weak compared to the Ti-Te contact, Cu-Te bonds largely contribute toward the overall stability. Due to the unique atomic arrangements, some Te atoms in the unit cell have unsaturated coordination, which presents 5s2 lone pairs on the Te atoms. This has been confirmed by the density of states (DOS) and electron localization function (ELF) calculations.

Effect of the Al Doping on the Sensing Behaviour of Carbon Nanotubes Toward Carbazochrome: a Computational Study

In the current report, the interaction of Al-doped carbon nanotubes (CNT) with carbazochrome, an anti-hemorrhagic or hemostatic agent, was investigated with the M06-2X functional and 6-31G* basis set. The global index including frontier molecular orbital energies, hardness, softness, chemical Gibbs energies and some parameters and NLO properties of Carbazochrome, Al doped CNT and complexes formed between their were calculated and evaluated. Electron localization function (ELF) calculations were performed to validate the essence of the formed bonding model progress along the interaction. It is obtained that polarizability of the complex are bigger than those of Carbazochrome and Al doped CNT. According to the maximum electron flow index, the electrophilicity power is increased by increasing the chemical potential, the decreasing chemical hardness. All obtained complexes are exergonic and thus thermodynamically favorable

Structural and Electronic Properties of Cu3InSe4

Single crystals of a new ternary chalcogenide Cu3InSe4 were obtained by induction melting, allowing for a complete investigation of the crystal structure by employing high-resolution single-crystal synchrotron X-ray diffraction. Cu3InSe4 crystallizes in a cubic structure, space group P4¯3m, with lattice constant 5.7504(2) Å and a density of 5.426 g/cm3. There are three unique crystallographic sites in the unit cell, with each cation bonded to four Se atoms in a tetrahedral geometry. Electron localization function calculations were employed in investigating the chemical bonding nature and first-principle electronic structure calculations are also presented. The results are discussed in light of the ongoing interest in exploring the structural and electronic properties of new chalcogenide materials.

Comparative study of the Zn1-xCdxSb and (Zn1-zCdz)13Sb10 solid solution series

Comparison of the (Zn1-zCdz)13Sb10 and Zn1-xCdxSb series allows better understanding of changes in the transport properties brought by the Cd substitution. Incorporation of a single dopant affects charge transport properties non-monotonously, and these changes are likely dependent on the intrinsic properties of the main phase. The dominant phonon scattering pathway in both solution series remains the Umklapp process even when the Zn:Cd ratio is 1:1, contrary to the expected point defect scattering. Lastly, the electron localization function (ELF) calculations suggested that the bonding character in ZnSb and Zn13Sb10 is well-described using the Zintl-Klemm concept, as a mix of covalent and ionic interactions.

The Role of the Bi3+ Lone Pair Effect in Bi(H3O)(SO4)2, Bi(HSO4)3, and Bi2(SO4)3.

Three new members in the Bi2O3-SO3-H2O system are identified by single crystal X-ray diffraction and Rietveld refinement after a fundamental examination of this phase space. Bi(H3O)(SO4)2 crystallizes in space group P21/c (no. 14, a = 1203.5(4), b = 682.9(2), c = 821.2(2) pm, β = 102.99(1)°, 861 independent reflections, 88 refined parameters, wR2 = 0.14) homeotypic with Nd(H3O)(SO4)2 featuring edge-sharing BiO9 polyhedra. Bi(HSO4)3 crystallizes in a new structure type in space group P1 (no. 2, a = 492.04(7), b = 910.8(1), c = 1040.8(2) pm, α = 85.443(5)°, β = 86.897(5)°, γ = 74.542(4)°, 3227 independent reflections, 154 refined parameters, wR2 = 0.05) comprising dimers of edge-sharing BiO8 polyhedra. For Bi2(SO4)3, a new modification crystallizing in space group P21/n (no. 14, a = 1308.03(7), b = 473.25(3), c = 1452.61(8) pm, β = 100.886(2)°, 3189 independent reflections, 155 refined parameters, wR2 = 0.03) isotypic to Sb2(SO4)3 with noncondensed BiO7 polyhedra is presented. The role of the Bi3+ lone pair effect as elucidated by density functional theory (DFT) calculations is discussed for all three compounds with respect to their structural and optical properties. Additionally, the Bi3+ lone pair activity is compared to the recently reported borosulfates Bi(H3O)[B(SO4)2]4 and Bi2[B2(SO4)6]. Geometrical calculations based on structural data are correlated with electron localization function (ELF) calculations to establish the origin of the direction and strength of the lone pair stereoactivity of Bi3+ in oxidic compounds. Finally, the thermal properties of the three compounds are reported.

Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn): High Chemical Flexibility Resulting in Good Nonlinear-Optical Properties.

Seven acentric sulfides Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) were grown by a high-temperature salt flux method. The crystal structures of the Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) compounds were determined by single-crystal X-ray diffraction with the aid of solid-state NMR spectroscopy. The Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi) compounds are isostructural and crystallize in the Ba6Ag4Sn4S16 structure type. The Sn-containing compound exhibits high structural similarity to Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi) with the presence of an interstitial atomic position partially occupied by Sn atoms. The chemical bonding characteristics of Ba6(Cu2.9Sn0.4)Sn4S16 were understood with electron localization function calculations coupled with crystal orbital Hamilton population calculations. The Ba-S and Cu-S interactions are dominantly ionic, but the Sn-S interactions consist of strong covalent bonding characteristics in Ba6(Cu2.9Sn0.4)Sn4S16. The monovalent Cu atoms, mixed with certain metals with various oxidation states, significantly shift the optical properties of the Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi) compounds. This results in a good balance between the second-harmonic-generation (SHG) response and laser damage threshold (LDT). Ba6(Cu1.9Zn1.1)Sn4S16 possesses a high SHG response and a high LDT of 2.8 × AGS and 3 × AGS, respectively. A density functional theory calculation revealed that CuS4 and SnS4 tetrahedra significantly contribute to the SHG response in Ba6(Cu2Mg)Sn4S16, which also confirmed that CuS4 tetrahedra are crucial for the stability and optical properties of the Ba6(CuxZy)Sn4S16 (Z = Mg, Mn, Zn, Cd, In, Bi, Sn) compounds revealed by electronic structure analysis.

Forming Platinide Phases under Pressure in the Cs–Pt System

A series of platinide-containing phases were identified as thermodynamically favorable compounds at high pressure (10 GPa) using an unbiased automatic crystal structure searching method. Density functional theory paired with a particle swarm optimization (PSO) algorithm supports the formation of Cs2Pt at ambient pressure, agreeing with experimental observations. The calculations then revealed that applying 10 GPa of pressure should result in three new phases: Cs2Pt with the Fe2P-type structure (space group P6̅2m; No. 189), Cs2Pt3 (space group Cmm2; No. 38), and CsPt3 (space group C2/m; No. 12). Subsequent hybrid electronic structure calculations showed that Cs2Pt is a semiconductor with the Fermi level falling in a band gap of 2.18 eV, whereas the Fermi level for Cs2Pt3 and CsPt3 falls into a pseudogap, suggesting a metallic character. Examining the chemical bonding in the Cs-rich phase (Cs2Pt) indicated that Cs–Pt ionic interactions dominate this structure, while Pt–Pt interactions are primary interactions in Pt-rich phases (Cs2Pt3 and CsPt3). Interestingly, the ambient pressure phase and all three high-pressure phases exhibit unusual oxidation states on transition-metal atoms. The Pt charge is approximated to approach −1 due to charge transfer between Cs and Pt, as illustrated by Bader’s QM-AIM charge analysis and electron localization function (ELF) calculations. These results support the presence of a rare pressure-stabilized platinide anion.

Carbazochrome carbon nanotube as drug delivery nanocarrier for anti-bleeding drug: quantum chemical study.

The interaction between drugs and single-walled carbon nanotubes is proving to be of fundamental interest for drug system of delivery and nano-bio-sensing. In this study, the interaction of pristine CNT with carbazochrome, an anti-hemorrhagic or hemostatic agent, was investigated with M06-2X functional and 6-31G* basis set. All probable positions of related adsorption for these kind drugs were thought-out to find out which one is energetically suitable. Based on the achieved data, the stronger interactions appeared the oxygen atom of C = O group and nitrogen atom of imine groups. The topology analysis of QTAIM (quantum theory of atoms in a molecule) method was accomplished to understand the properties of interactions between the CNT and carbazochrome. Frontier molecular orbital energies of all systems, global index including stiffness, softness, chemical Gibbs energies, and electrophilicity parameters, as well as some other important physical data such as dipole moment, polarizability, anisotropy polarisibility, and hyperpolaribility were calculated, evaluated, and then compared together. The essence of the formed bonding model progress along the reaction roots was further validated using electron localization function (ELF) calculations. The highest values of adsorption energies were determined in the range of 18.24 up to 22.12kcalmol-1 for these kind systems. The acceptable recovery time of 849s was obtained for the desorption of carbazochrome from the CNT surface under UV-light. The final results exhibit that carbazochrome can serve as a promising carrier and also as sensitive sensors in any kind of practical application.

Synthesis, Crystal Growth, Electronic Properties and Optical Properties of Y6IV2.5S14 (IV=Si, Ge)

AbstractTwo isostructural ternary acentric sulfides, Y6Si2.5S14 (1) and Y6Ge2.5S14 (2) were re‐investigated to understand the origin of the chemical flexibility of RE6BxCyCh14(RE=Y, La−Lu; B=Si, Ge, Sn, Al, Ga; C=monovalent M+ (Ag, Na, Li, etc.), divalent M2+ (Mg, Cr, Ni, Zn, etc.), trivalent M3+ (Al, In, Ga, etc.), tetravalent M4+ (Si, Ge, Sn) and pentavalent M5+ (Sb), Ch=S, Se), which consists of ∼444 isostructural compounds. Y6IV2.5S14 (IV=Si, Ge) were synthesized by a high‐temperature salt flux method. The crystal structures of Y6IV2.5S14 (IV=Si, Ge) are constructed by [YS8] polyhedra, [Si1S6] octahedra, and [Si2S4] tetrahedra. The Si1 atom displaces from the center of [Si1S6] octahedra with partial occupancy, which can be replaced by various metals, and mainly accounts for the chemical flexibility of the RE6BxCyCh14 family. The bonding pictures of Y6Si2.5S14 were studied by electron localization function (ELF) and crystal orbital Hamilton population (COHP) calculations. Y6Si2.5S14 is evaluated as an indirect semiconductor with a bandgap of 2.4(1) eV measured by UV‐Vis. The indirect bandgap of Y6Ge2.5S14 is 1.7(1) eV. Y6IV2.5S14 (IV=Si, Ge) are not type‐I phase‐matchable materials. For samples of 47 μm particle size, Y6Si2.5S14 and Y6Ge2.5S14 own good second harmonic generation (SHG) responses of ∼3.0×AGS and ∼2.8×AGS respectively. Y6Si2.5S14 and Y6Ge2.5S14 possess high laser damage threshold (LDT) of ∼5.5×AGS and ∼5.2×AGS respectively.

Experimental and theoretical spectroscopic (FT-IR, FT-Raman, UV-VIS) analysis, natural bonding orbitals and molecular docking studies on 2-bromo-6-methoxynaphthalene: A potential anti-cancer drug

The vibrational, electronic and charge transfer studies on 2-bromo-6-methoxynaphthalene (2BMN) were done using DFT method with B3LYP/6-311++G(d,p) theory using GAUSSIAN 09W software. Theoretical and experimental investigations on FT-IR and FT Raman were executed on 2BMN. The calculated vibrational wavenumbers were scaled using suitable scaling factors and vibrational assignments were done to all modes of vibrations using Potential Energy Distribution (PED). Frontier Molecular Orbitals were calculated using TD-DFT method and the HOMO-LUMO energy gap was also obtained. Other electronic properties and global parameters for 2BMN were found using the HOMO-LUMO energy values. An energy gap of 4.208 eV shows the stability of the molecule. The reactive sites were predicted using Molecular Electrostatic Potential (MEP), Electron Localization Function (ELF) and Fukui calculations. Hence all electrophilic sites and nucleophilic areas of the molecule were determined. The delocalization of electron density was studied using NBO calculations. The intramolecular transitions and stability of structure were explained using in detail using the former. As the compound satisfies drug-like properties and has a softness value (indicating its less toxic nature), it may be used as a pharmaceutical product. Molecular docking studies were made and the protein-ligand binding properties were discussed. It was found out that title compound exhibits anti-cancer activities. The low binding energy predicts that the compound may be modified as a drug for treating Cancer.

Predicted Stable Structures of the Li-Ag System at High Pressures.

In this letter, we have performed extensive swarm-intelligence structure searching simulations on the Li-Ag system at high pressures. As a result, Li4Ag is predicted to become stable at high pressures. Moreover, we have also identified several pressured-stabilized structures for the Li-Ag system. The further electronic density of states and electron localization function calculations reveal the metallic feature of predicted structures. Crystal orbital Hamilton population (COHP) calculations indicate the strong interaction between Li atoms, leading to the formation of Li-ring configurations in Li-rich Li-Ag structures. Our current results highlight the role of pressure in determining the stability for unexpected stoichiometry in the Li-Ag system.

Computational Rationalization of the Interaction of Fe(CO)4 and Substituted Benzyne Ligands

This study investigates the effect of different substituents on the interactions between Fe(CO)4 and substituted benzynes (C6X4, X = H, F, Cl, Br, CN, Me) in Fe(CO)4(η2-C6X4) complexes using MPW1PW91-based quantum mechanical calculations. In this respect, the study evaluates the influence of electron withdrawing and donating groups on the Fe-Cbenzyne bond distances and topological properties. In addition, the frontier orbital analysis is used to illustrate the electronic structure of complexes, and the percentage composition in terms of the defined groups of frontier orbitals is evaluated. To obtain insights into the physical nature of Fe-Cbenzyne bonds, we extensively use the energy decomposition analysis (EDA) and Bader’s Quantum Theory of Atoms-in-Molecules (QTAIM). To this end, in addition to the examination of the properties of bond critical points, we apply the Pendas interacting quantum atoms (IQA) scheme, which enables a rigorous and physical study of Fe-Cbenzyne bonds in these complexes. Also, electron localization function (ELF) and localized-orbital locator (LOL) calculations are used to illustrate Fe-C bonds in the investigated complexes.

Computational rationalization of the interaction of Fe(CO)4 and substituted benzyne ligands

This study investigates the effect of different substituents on the interactions between Fe(CO)4 and substituted benzynes (C6X4, X = H, F, Cl, Br, CN, Me) in Fe(CO)4(η2-C6X4) complexes using MPW1PW91-based quantum mechanical calculations. In this respect, the study eva­luates the influence of electron withdrawing and donating groups on the Fe—Cbenzyne bond distances and topological properties. In addition, the frontier orbital analysis is used to illustrate the electronic structure of complexes, and the percentage composition in terms of the defined groups of frontier orbitals is evaluated. To obtain insights into the physical nature of Fe—Cbenzyne bonds, we extensively use the energy decomposition analysis (EDA) and Bader's Quantum Theory of Atoms-in-Molecules (QTAIM). To this end, in addition to the examination of the properties of bond critical points, we apply the Pendas interacting quantum atoms (IQA) scheme, which enables a rigorous and physical study of Fe—Cbenzyne bonds in these complexes. Also, electron localization function (ELF) and localized-orbital locator (LOL) calculations are used to illustrate Fe—C bonds in the investigated complexes.