Clemence Corminboeuf

Bio: Clemence Corminboeuf is an academic researcher from University of Erlangen-Nuremberg. The author has contributed to research in topics: Möbius aromaticity. The author has an hindex of 1, co-authored 1 publications receiving 757 citations.

Magnetic criteria of aromaticity

Abstract: This review describes the current state of magnetic criteria of aromaticity. The introduction contains the fundamentals of ring currents in aromatic and antiaromatic systems, followed by a brief description of experimental and computational tools: NMR, diamagnetic susceptibility exaltation, current density analyses (CDA) and nucleus independent chemical shifts (NICS). This is followed by more comprehensive chapters: NMR – focusing on the work of R. Mitchell – NICS and CDA – describing the progress and development of the methods to their current state and presenting some examples of representative work.

Wavefunction and reactivity study of benzo[a]pyrene diol epoxide and its enantiomeric forms

Abstract: Benzo[a]pyrene is a known carcinogen, which derives from fossil fuel combustion, cigarette smoke, and generic biomass combustion including traffic emissions. This potent carcinogen has a well-known mechanism of action, leading to the formation of adducts with the DNA, primarily at guanosine positions. The reactivity and chemistry of this notorious compound are, however, dependent on the electronic configuration of the biologically activated metabolite, the benzo[a]pyrene diol epoxide. The activated metabolite exists mainly as four isomers, which have particular chemical reactivities toward guanosine sites on the DNA. These isomers exert also a different carcinogenicity compared to one another, which is a feature that is conventionally attributed to their geometry. However, the reactivity and properties of the isomers are not fully defined, and a determination of these properties by wavefunction behavior is required. This study reports the electronic properties of the benzo[a]pyrene diol epoxide enantiomers, along with a detailed analysis of the energy landscape, geometry, and electronic configuration of the epoxide ring. The results show that the epoxide ring, the core of the reactivity, bears different properties at the level of wavefunction for each isomer. Each of the isomers has a distinct profile on the epoxide ring, in terms of hydrogen bonds and in terms of the non-covalent interaction between the diol groups and the epoxide. These profiles generate differential reactivities of epoxide group, which can be attributed to its local bond lengths, the electron localization function, and polarized bonds. Most interestingly, the quantum chemical calculations showed also that the epoxide ring is inclined more perpendicularly toward the angular ring plane for the more carcinogenic isomers, a feature which suggests a potential geometrical relationship between the inclination of the epoxide group and its interaction with the guanosine group upon adduct formation. Our results introduce novel and crucial information, which assist in understanding the mechanism of toxic potential of this known molecule, and display the strength and level of detail of applying quantum chemical methods to reveal the reactivity, energy properties, and electronic properties of a mutagen.

13C NMR Spectroscopy of “Arduengo-type” Carbenes and Their Derivatives

Abstract: Since the isolation and crystallographic characterization of the first stable N-heterocyclic carbene in early 1991,1 nucleophilic diaminocarbenes (also known as “Arduengotype” carbenes) and their analogues have emerged as a powerful class of carbon-based ligands with broad applications in metal-based catalytic reactions.2-12 The main reason for their success in catalysis is their superior properties as ligands in comparison with their phosphine counterparts.11,13-18 In addition, carbene organocatalysis has emerged as an extremely fruitful area of research in synthetic organic chemistry. The benzoin condensation, the Stetter reaction, transformations involving homoenolates, 1,2-additions, transesterifications, and ring opening polymerizations are among the many reactions promoted by nucleophilic carbenes. Several excellent reviews, chapters, and books highlighting the recent progress of nucleophilic carbenes in metal-based catalysis and organocatalysis are available.7,9,11-16,19-24 Significant efforts have been made to better understand the unique properties associated with the free nucleophilic carbenes using a wide range of experimental techniques. X-ray diffraction,1,25 neutron diffraction,26,27 photoelectron spectroscopy,28 cyclic voltammetry,29-34 NMR spectroscopy, and IR spectroscopy10,35-40 are among the experimental techniques employed in these studies. The experimental methods have been complemented by theoretical investigations, which have become extremely important because they enable the study of a great number of related systems, a task that would be difficult or sometimes impossible to achieve experimentally. Density functional theory and molecular orbital theory have been employed for the study of these intriguing species.26-28,41-49

On the performance of some aromaticity indices: a critical assessment using a test set.

Abstract: Aromaticity is a central chemical concept widely used in modern chemistry for the interpretation of molecular structure, stability, reactivity, and magnetic properties of many compounds. As such, its reliable prediction is an important task of computational chemistry. In recent years, many methods to quantify aromaticity based on different physicochemical properties of molecules have been proposed. However, the nonobservable nature of aromaticity makes difficult to assess the performance of the numerous existing indices. In the present work, we introduce a series of fifteen aromaticity tests that can be used to analyze the advantages and drawbacks of a group of aromaticity descriptors. On the basis of the results obtained for a set of ten indicators of aromaticity, we conclude that indices based on the study of electron delocalization in aromatic species are the most accurate among those examined in this work.

Excited state aromaticity and antiaromaticity: opportunities for photophysical and photochemical rationalizations.

Abstract: Excited State Aromaticity and Antiaromaticity : Opportunities for Photophysical and Photochemical Rationalizations