176 research outputs found

    Electronic and structural data of 4’-substituted bis(2,2’;6’2’’-terpyridine)manganese in mono-, bis-, tris- and tetra-cationic states from DFT calculations

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    This data article provides density functional theory calculated structural (bond lengths and angles, coordinates of optimized geometries) and electronic (Mulliken spin population and character of frontier molecular orbitals) data of a series of 4’-substituted bis(2,2’;6’2’’-terpyridine)manganese complexes in four different oxidation states. The bis-cationic (n = 2) [Mn(tpy)2]2+ complexes are experimentally well known (Sjödin et al., 2008), while little or none experimental structural data of the tetra-cationic (n = 4, Romain et al., 2009, 2009), tris-cationic (n = 3, Romain et al., 2009) and mono-cationic (n = 1, Wang et al., 2014) [Mn(tpy)2]n+ complexes are available. For more insight into the provided data, see related research article “Redox chemistry of bis(terpyridine)manganese(II) complexes – a molecular view” (Conradie, 2022)

    Carbonyl Substitution in beta-Diketonatodicarbonyl-rhodium(I) by Cyclo-octadiene: Relationships with Experimental, Electronic and Calculated Parameters

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    Source at https://journals.co.za/content/chem/66/1/EJC132441.The substitution rate constant of the reaction between [Rh(β-diketonato)(CO)2] and cyclo-octadiene is related to various empirical parameters and density functional theory calculated energies and charges, β-diketonato = R'COCHCOR. Results indicate that especially the Hammett meta substituent constants (σ), the Lever electronic parameters (EL) and the density functional theory calculated energies and charges predict the substitution rate constant to a high degree of accuracy, for example: In k2=8.48 (σR+σR') - 2.24 (R2=0.99)=31.8 ΣEL - 63.0 (R2=0.99)=-9.16 EHOMO - 52.1 (R2=0.97)=101 ΣQMulliken(Rh(CO)2) - 49.9 (R2 = 0.99)

    Dimethylsulfoxide (DMSO) Clusters Dataset: DFT Relative Energies, Non-Covalent Interactions, and Cartesian Coordinates

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    Theoretical understanding of dimethylsulfoxide (DMSO) liquid depends on the understanding of the DMSO clusters. In this work, we provide the structures and the energetics of the DMSO clusters. The structures have been generated using ABCluster and further optimized at the MP2/aug-ccpVDZ level of theory. The final structures have been optimized at two different levels of theory: PW6B95D3/aug-ccpVDZ and ωB97XD/aug-cc-pVDZ. The Cartesian coordinates of the structures optimized at the MP2/aug-cc-pVDZ level of theory are also reported. The relative energies of the structures can be used to locate the most favorable structures of the DMSO clusters. The Cartesian coordinates of the structures can be used for further investigations on DMSO clusters. In addition, we report the data related to the quantum theory of atoms in molecule (QTAIM) analysis of the investigated clusters. The QTAIM data reported in this work can be used to understand and determine the nature of noncovalent interactions in DMSO clusters. For further reading and discussion on the data reported here, please report to the original manuscript Malloum and Conradie (2022) [1]

    B12 and F430 models: Metal- versus ligand-centered redox in cobalt and nickel tetradehydrocorrin derivatives

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    DFT calculations with the well-tested OLYP and B3LYP* exchange-correlation functionals (along with D3 dispersion corrections and all-electron ZORA STO-TZ2P basis sets) and careful use of group theory have led to significant insights into the question of metal- versus ligand-centered redox in Co and Ni B,C-tetradehydrocorrin complexes. For the cationic complexes, both metals occur in their low-spin M(II) forms. In contrast, the charge-neutral states vary for the two metals: while the Co(I) and CoII-TDC•2– state are comparable in energy for cobalt, a low-spin NiII-TDC•2– state is clearly preferred for nickel. The latter behavior stands in sharp contrast to other corrinoids that reportedly stabilize a Ni(I) center

    Twist-Bent Bonds Revisited: Adiabatic Ionization Potentials Demystify Enhanced Reactivity

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    Explicit calculations of vertical and adiabatic ionization potentials of cyclopropane derivatives with modern DFT methods have underscored the possibility of unusually large reorganization energies (defined as the difference between vertical and adiabatic ionization potentials) of 0.5–1.0 eV for several compounds. Such is the case for ionization of the twist-bent σ-bond of trans-bicyclo[4.1.0]hept-3-ene (trans-3-norcarene), for which B3LYP*-D3 calculations predict an adiabatic IP of 7.92 eV. The corresponding value for the cis-norcarene is 8.34 eV. The significantly lower adiabatic IP provides an attractive explanation for the higher reactivity of the trans compound under oxidative conditions. Large reorganization energies are also found for the ionization of cyclopropane, bicyclo[1.1.0]butane, and bicyclo[2.1.0]pentane. In sharp contrast, an exceptionally small reorganization energy is associated with the ionization of tricyclo[1.1.1.0]pentane ([1.1.1]propellane)

    QTAIM analysis dataset for non-covalent interactions in curan clusters

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    Furan clusters are very important to understand the dynam- ics and properties of the furan solvent. They can be used combined with quantum cluster equilibrium theory to theo- retically determine the thermodynamics properties of the fu- ran solvent. To understand the structures of the furan clus- ters, one needs to understand the non-covalent interactions that hold the furan molecules together. In this paper, we have provided the data necessary to understand the non-covalent interactions in furan clusters. Firstly, the structures of the furan clusters have been generated using classical molecu- lar dynamics as implemented in the ABCluster code. Sec- ondly, the generated structures have been fully optimized at the MP2/aug-cc-pVDZ level of theory. The optimized Carte- sian coordinates of all the investigated structures are re- ported in this work to enable further investigations of the furan clusters. These Cartesian coordinates will save compu- tational time for all further investigations involving the fu- ran clusters. Thirdly, to understand the nature of the non- covalent interactions in furan clusters, we have performed a quantum theory of atoms in molecule (QTAIM) analysis using AIMAll program. Using QTAIM, we have provided the critical points, bond paths and their related properties for all the in- vestigated structures. These data can be used to identify and classify the non-covalent interactions in furan clusters

    Redox behaviour of imino-β-diketonato ligands and their rhodium(I) complexes

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    The redox behaviour of bidentate (BID) ligands containing either two O donor atoms (O,O’-BID ligand), a N and an O donor atom (N,O-BID ligand) or two N donor atoms (N,N’-BID ligand), and their rhodium complexes, are presented. The experimental reduction potential of the L,L’-BID ligands (L,L’ = N and O) and the experimental oxidation potential of [Rh(L,L’-BID)(CO)(PPh3)] complexes relate linearly. Though, complexes with an aromatic substituent group on the L,L’-BID ligand deviate slightly from the trend, due to the resonance effect through the extended π-system of the latter complexes. The experimental reduction potential of the L,L’-BID ligands relate linearly to the computational chemistry calculated energies of their lowest unoccupied molecular orbitals (LUMOs), whereas the experimental oxidation potential of the [Rh(L,L’-BID)(CO)(PPh3)] complexes related linearly to the computational chemistry calculated energies of their highest occupied molecular orbitals (HOMOs). In the latter relationship it is found that the data points cluster in four groups depending on both the donor atoms (N and O) and the substituent groups (amount of CF3 groups) on the coordinating L,L’-BID ligand

    Data to Understand the Nature of Non-Covalent Interactions in the Thiophene Clusters

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    We have reported herein the data to understand the nature and number of non-covalent interactions that stabilize the structures of the thiophene clusters. In addition, we have also provided the optimized Cartesian coordinates of all the structures of the investigated thiophene clusters. Initially, the geometries have been generated using the ABCluster code which performs a global optimization to locate local and global minima structures of molecular clusters. The located geometries have been optimized at the MP2/aug-ccpVDZ level of theory using Gaussian 16 suite of programs. To understand the nature of non-covalent interactions, we have performed a quantum theory of atoms in molecules (QTAIM) analysis on all the structures of the thiophene dimer. Furthermore, the QTAIM analysis has been performed also on the most stable structure of the thiophene trimer and tetramer. We have used the AIMAll program to perform the QTAIM analysis. The data reported in this paper contains the critical points, the bonds paths and their related properties, for each investigated structures. Besides, the data contains the optimized Cartesian coordinates of all the investigated structures of the thiophene clusters. This can be use for any further investigations involving thiophene clusters. For further information and analysis, the reader is referred to the original related research article (Malloum and Conradie, 2022)

    Porphyryne

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    Density functional theory calculations with the B3LYP*-D3 method with large STO-QZ4P basis sets unambiguously predict a singlet ground state for Zn-porphyryne. However, the calculations also predict a low singlet–triplet gap of about 0.4 eV and a high adiabatic electron affinity of 2.4 eV. Accordingly, the reactivity of porphyryne species may be dominated by electron transfer, hydrogen abstraction, and proton-coupled electron transfer processes

    The Perfluoro Cage Effect: A Search for Electron-Encapsulating Molecules

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    Quantum chemical calculations have for some time predicted that perfluorinated polyhedral organic molecules should exhibit a low-energy LUMO consisting of the overlapping inward-pointing lobes of the C−F σ* orbitals. Accordingly, these molecules should be able to encapsulate an electron within the interior of their cavities. Inspired by the recent confirmation of this prediction for perfluorocubane, we have sought to identify additional perfluorinated cage molecules capable of this remarkable behavior, which we refer to as the perfluoro cage effect (PCE). Using DFT calculations with multiple well-tested exchange-correlation functionals and large STO-QZ4P basis sets, we have identified several systems including [n]prismanes (n = 3−6), [n]asteranes (n = 3−5), twistane, and two norbornadiene dimer cages that clearly exhibit the PCE. In other words, they exhibit a low-energy LUMO belonging to the total symmetric irreducible representation of the point group in question and adiabatic electron affinities ranging from somewhat under 1 eV to over 2 eV. A pronounced size effect appears to hold, with larger cages exhibiting higher electron affinities (EAs). The largest adiabatic EAs, well over 3 eV, are predicted for perfluorinated dodecahedrane and C60. In contrast, the PCE is barely discernible for perfluorinated tetrahedrane and bicyclo[1.1.1]pentane
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