Topological aspects of chemical reactivity. Valency changes in the course of chemical reactions

The Jug and Gopinathan approach to the use of valency changes for the characterization of chemical reactions is generalized by incorporating it into the framework of the recently proposed topological description of chemical reactivity in terms of the overlap determinant method. The conclusions of the simple topological analysis agree with the results of the direct quantum chemical treatment, indicating thus that the overlap determinant method depicts correctly the principal features of the electron density reorganization occuring during the chemical reactions.

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Charge Density Analysis and Transport Properties of TTF Based Molecular Nanowires: A DFT Approach

Journal of Nanoscience ◽

10.1155/2015/806181 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Karuppannan Selvaraju ◽

Poomani Kumaradhas

Keyword(s):

Density Distribution ◽

Charge Density ◽

Electron Density ◽

Quantum Chemical ◽

Molecular Conformation ◽

Topological Analysis ◽

Basis Set ◽

Bond Critical Point ◽

Chemical Calculation ◽

Energy Density Distribution

The present study has been performed to understand the charge density distribution and the electrical characteristics of Au and thiol substituted tetrathiafulvalene (TTF) based molecular nanowire. A quantum chemical calculation has been carried out using DFT method (B3LYP) with the LANL2DZ basis set under various applied electric fields (EFs). The bond topological analysis characterizes the terminal Au–S and S–C bonds as well as all the bonds of central TTF unit of the molecule. The variation of electron density and Laplacian of electron density at the bond critical point of bonds for zero and different applied fields reveal the electron density distribution of the molecule. The molecular conformation, the variation of atomic charges and energy density distribution of the molecule have been analyzed for the various levels of applied EFs. The HOMO-LUMO gap calculated from quantum chemical calculations has been compared with the value calculated from the density of states. The variation of dipole moment due to the polarization effect and the I-V characteristics of the molecule for the various applied EFs have been well discussed.

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Study of molecular interactions and chemical reactivity of the nitrofurantoin–3-aminobenzoic acid cocrystal using quantum chemical and spectroscopic (IR, Raman, 13C SS-NMR) approaches

CrystEngComm ◽

10.1039/c7ce00864c ◽

2017 ◽

Vol 19 (28) ◽

pp. 3921-3930 ◽

Cited By ~ 19

Author(s):

Anuradha Shukla ◽

Eram Khan ◽

Karnica Srivastava ◽

Kirti Sinha ◽

Poonam Tandon ◽

...

Keyword(s):

Molecular Interactions ◽

Quantum Chemical ◽

Chemical Reactivity ◽

Aminobenzoic Acid ◽

Vibrational Characterization

Inquiries of structural reactivity, molecular interactions and vibrational characterization of drugs are essential in understanding their behaviour.

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Unveiling the Different Chemical Reactivity of Diphenyl Nitrilimine and Phenyl Nitrile Oxide in [3+2] Cycloaddition Reactions with (R)-Carvone through the Molecular Electron Density Theory

Molecules ◽

10.3390/molecules25051085 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1085 ◽

Cited By ~ 1

Author(s):

Mar Ríos-Gutiérrez ◽

Luis R. Domingo ◽

M’hamed Esseffar ◽

Ali Oubella ◽

My Youssef Ait Itto

Keyword(s):

Electron Density ◽

Density Functional ◽

Chemical Reactivity ◽

Topological Analysis ◽

Nitrile Oxide ◽

Conceptual Density Functional Theory ◽

Functional Theory ◽

Molecular Electron ◽

Molecular Electron Density Theory

The [3+2] cycloaddition (32CA) reactions of diphenyl nitrilimine and phenyl nitrile oxide with (R)-carvone have been studied within the Molecular Electron Density Theory (MEDT). Electron localisation function (ELF) analysis of these three-atom-components (TACs) permits its characterisation as carbenoid and zwitterionic TACs, thus having a different reactivity. The analysis of the conceptual Density Functional Theory (DFT) indices accounts for the very low polar character of these 32CA reactions, while analysis of the DFT energies accounts for the opposite chemoselectivity experimentally observed. Topological analysis of the ELF along the single bond formation makes it possible to characterise the mechanisms of these 32CA reactions as cb- and zw-type. The present MEDT study supports the proposed classification of 32CA reactions into pdr-, pmr-, cb- and zw-type, thus asserting MEDT as the theory able to explain chemical reactivity in Organic Chemistry.

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Topological aspects of chemical reactivity

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19840455 ◽

1984 ◽

Vol 49 (2) ◽

pp. 455-473 ◽

Cited By ~ 15

Author(s):

Robert Ponec

Keyword(s):

Group Theory ◽

Quantum Chemical Calculations ◽

Chemical Reactions ◽

Quantum Chemical ◽

Chemical Reactivity ◽

Simple Formalism

A simple formalism is proposed allowing to characterise the nature of chemical reactions. In comparison with existing techniques the presented method does not require to perform either quantum chemical calculations or to use the group theory. This makes the method convenient not only for pedagogical purposes but also as a routine tool for organic chemists.

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How a Quantum Chemical Topology Analysis Enables Prediction of Electron Density Transfers in Chemical Reactions. The Degenerated Cope Rearrangement of Semibullvalene

The Journal of Physical Chemistry Letters ◽

10.1021/jz300974v ◽

2012 ◽

Vol 3 (17) ◽

pp. 2500-2505 ◽

Cited By ~ 22

Author(s):

Patricio González-Navarrete ◽

Juan Andrés ◽

Slawomir Berski

Keyword(s):

Electron Density ◽

Chemical Reactions ◽

Quantum Chemical ◽

Cope Rearrangement ◽

Topology Analysis ◽

Chemical Topology ◽

Quantum Chemical Topology

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The lp(O)...π-interactions in 1-[1-(methoxycarbonylmethylthio)methyl]-3,5-dimethylisocyanurate: topological analysis of the electron density distribution from X-ray diffraction data and quantum chemical calculations

Russian Chemical Bulletin ◽

10.1007/s11172-013-0246-3 ◽

2013 ◽

Vol 62 (8) ◽

pp. 1699-1706 ◽

Cited By ~ 2

Author(s):

Yu. K. Voronina ◽

I. A. Litvinov ◽

K. A. Lyssenko

Keyword(s):

Density Distribution ◽

Electron Density ◽

Quantum Chemical Calculations ◽

Diffraction Data ◽

Quantum Chemical ◽

Electron Density Distribution ◽

Topological Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Π Interactions

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Charge density in crystalline citrinin from X-ray diffraction at 19 K

Canadian Journal of Chemistry ◽

10.1139/v96-129 ◽

1996 ◽

Vol 74 (6) ◽

pp. 1145-1161 ◽

Cited By ~ 32

Author(s):

Pietro Roversi ◽

Felicita Merati ◽

Riccardo Destro ◽

Mario Barzaghi

Keyword(s):

Electron Density ◽

Chemical Reactivity ◽

Topological Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Bond Path ◽

Topological Features ◽

Path Lengths ◽

The Stability ◽

Experimental Electron Density

For the fungal metabolite citrinin, C13H14O5, the total experimental electron distribution ρ(r) and its Laplacian [Formula: see text] have been obtained from an extensive set (36 564 measurements) of single-crystal X-ray diffracted intensities at a temperature of 19 ± 2 K. Relevant steps in data collection and processing are reported. The resulting 7698 independent intensity data have been analysed with a multipole (pseudoatoms) formalism. The topological properties of ρ(r) have been determined according to the quantum theory of atoms in molecules. CC and CO bond path lengths have been obtained by numerical integration; their values are found to be well correlated with those of the electron density at the bond critical points. Topological features have been used to characterize the extension of the conjugated system of the molecule, and to confirm the stability of its rings, particularly the two formed by intramolecular H bonds. Maps of [Formula: see text] are presented, showing details in the valence charge distribution and providing a very sensitive tool for analysing dependence of the density on the model adopted to interpret X-ray data. The known chemical reactivity of the molecule towards nucleophiles at a Csp2 atom is confirmed by the shape of the molecular reactive surface (the zero envelope of [Formula: see text]). Key words: experimental electron density, low-temperature X-ray diffraction, topological analysis, Laplacian of ρ.

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Experimental and theoretical characterization of the Zn—Zn bond in [Zn2(η5-C5Me5)2]

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768107045880 ◽

2007 ◽

Vol 63 (6) ◽

pp. 862-868 ◽

Cited By ~ 31

Author(s):

Juan F. Van der Maelen ◽

Enrique Gutiérrez-Puebla ◽

Ángeles Monge ◽

Santiago García-Granda ◽

Irene Resa ◽

...

Keyword(s):

Electron Density ◽

Density Functional ◽

Topological Analysis ◽

Open Shell ◽

Synchrotron Diffraction ◽

Functional Theory ◽

Metal Metal ◽

Moller Plesset ◽

Experimental Electron Density

The existence and characterization of a bond between the Zn atoms in the recently synthesized complex [Zn2(η5-C5Me5)2], as well as between Zn and ligand C atoms is firmly based on neutron diffraction and low-temperature X-ray synchrotron diffraction experiments. The multipolar analysis of the experimental electron density and its topological analysis by means of the `Atoms in Molecules' (AIM) approach reveals details of the Zn—Zn bond, such as its open-shell intermediate character (the results are consistent with a typical metal–metal single bond), as well as many other topological properties of the compound. Experimental results are also compared with theoretical ab initio calculations of the DFT (density functional theory) and MP2 (Møller-Plesset perturbation theory) electron densities, giving a coherent view of the bonding in the complex. For instance, charges calculated from the AIM approach applied to the atomic basin of each Zn atom are, on average, +0.72 e from both the experimental and the theoretical electron density, showing a moderate charge transfer from the metal, confirmed by the calculated topological indexes.

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Topological Aspects of Chemical Reactivity. Electron Correlation in the Course of Chemical Reactions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19931751 ◽

1993 ◽

Vol 58 (8) ◽

pp. 1751-1760 ◽

Cited By ~ 4

Author(s):

Robert Ponec ◽

Martin Strnad

Keyword(s):

Chemical Reactions ◽

Electron Correlation ◽

Energy Barrier ◽

Chemical Reactivity ◽

Similarity Index ◽

Pericyclic Reactions ◽

Correlation Effects ◽

Transient Species

The second order similarity index gRP, which has been proposed recently as a new means for a qualitative characterization of correlation effects in chemical reactivity, was generalized by incorporation into a topological model of the overlap determinant method. The resulting approach, which provides information about the variation of electron correlation during chemical reactions, was applied to the investigation of several selected pericyclic reactions. Consistent with what can be expected, the role of electron correlation was found to be the most critical for transition states of other transient species near the top of the energy barrier. The systematic differences in the extent of electron correlation between allowed and forbidden reactions are also discussed.

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