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Abstract: The hydrogenation reaction of multiple bonds that is mediated by geminal aminoborane‐based frustrated Lewis pairs (FLPs) has been explored by means of density functional theory calculations. It was found that the release of the activated dihydrogen occurred in a concerted, yet highly asynchronous, manner. The physical factors that control the transformation were quantitatively described in detail by using the activation strain model of reactivity in combination with the energy decomposition analysis method. This approach suggested a cooperative double hydrogen‐transfer mechanism, which involves the initial migration of the protic (N)H followed by the nucleophilic attack of the (B)H hydride to the carbon atom of the multiple bond. The influence of both the substituents directly attached to the boron atom of the initial FLP and the nature of the multiple bond on the transformation was also investigated. [ABSTRACT FROM AUTHOR]

H2 activation mediated by geminal aminoborane-based frustrated Lewis pairs (FLPs; R2N-CH2-BR′2) has been computationally explored within the density functional theory framework. It is found that the activation barrier of this process as well as the geometry of the corresponding transition states strongly depend on the nature of the substituents directly attached either to the acidic or the basic centers of the FLPs. The physical factors controlling the whole activation path are quantitatively described in detail by means of the activation strain model of reactivity combined with the energy decomposition analysis method. This methodology suggests a highly orbital-controlled mechanism where the degree of charge transfer cooperativity between the most important donor-acceptor orbital interactions, namely LP(N)→σ*(H2) and σ(H2)→pπ(B), along the reaction coordinate constitutes a suitable indicator of the reaction barrier. [ABSTRACT FROM AUTHOR]

Using the reaction electronic flux, a new tool aimed at identifying and characterizing the electronic activity taking place during a chemical process, the chelotropic and cycloaddition reactions of 1,3-butadiene with sulfur dioxide are revisited. The mechanisms of both reactions were studied within the framework of the reaction force analysis; the electronic activity determined through the reaction electronic flux was rationalized in terms of chemical events, bond forming or breaking processes, and polarization and transfer effects localized on the reactants species. The results show interesting features and differences between both the mechanisms; while the chelotropic path is driven by through space electrostatic interactions, the cycloaddition reaction is mainly driven by through bond electronic activity. The relation between these findings and the experimentally found kinetic (cycloaddition) and thermodynamic (chelotropic reaction) control is discussed. Int J Quantum Chem, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Five new heteroleptic copper(I) complexes (C1‐5) of the type [Cu(dpa)(P,P)]BF4 based on dipyridylamine (dpa) as N,N ligand and commercial diphosphines as P,P ancillary ligands have been synthesised through a simple methodology with high yields. All complexes were thoroughly characterised by spectroscopic and spectrometric techniques, as well by theoretical calculations. These showed Metal to Ligand Charge Transfer (MLCT) absorptions in the 300–370 nm region, and emission in the 450–520 nm region with quantum yields and lifetimes that depend on the nature of the P,P ligand. The photocatalytic performance of copper(I) complexes C1‐5 was evaluated for their use as photoredox catalysts in ATRA reactions, decarboxylative coupling and an Appel‐type reaction. The use of readily available dpa as N,N ligand constitutes an attractive alternative to the well‐established phenanthroline ligands typically used in photocatalysis. [ABSTRACT FROM AUTHOR]

To analyze the evolution of a chemical property along the reaction path, it is necessary to extract all the information from a set of electronic structure computations. However, this process is time‐consuming and prone to human error. Here we introduce intrinsic reaction coordinate (IRC)‐Analysis, a new extension in Eyringpy, to monitor the evolution of chemical properties along the intrinsic reaction coordinate, including the complete reaction force analysis. IRC‐Analysis collects the entire data set for each snapshot of the reaction coordinate, avoiding human error in data capture, and allowing the study of several chemical reactions in seconds. Eyringpy is written in Python, has a simple input format, and no programming skills are required. Python's Matplotlib library is used for plotting the evolution of the properties along the reaction coordinate. This version can analyze the evolution of bond distances, angles, Wiberg bond indices, natural charges, dipole moments, and orbital energies (and related properties). [ABSTRACT FROM AUTHOR]