Exploring the reactivity of carbene supported diboraanthracene towards dihydrogen activation. (15th September 2019)

• Record Type: Journal Article
• Authors: Kashyap, Chayanika; Rohman, Shahnaz S.; Ullah, Sabnam S.; Guha, Ankur K.
• Is Part Of: Polyhedron. Volume 170(2019)
• Page Start: 666
• Page End: 673
• Publication Date: 2019-09-15
• Subjects: NHC -- Diboraanthracene -- H2 activation -- Quantum chemical calculation -- Reversibility; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2019.06.043
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: DFT calculations have been performed to explore the reactivity of different N-heterocyclic carbene stabilized diboraanthracences towards dihydrogen activation. Abstract: Quantum chemical calculations have been carried out on some N-heterocyclic carbene (NHC) stabilized boraanthracenes to investigate their possibility to act as H2 activators. Different coordination modes such as normal, abnormal and remote NHC are considered. Moreover, a 1, 3, 2, 5-diazadiborinine molecule, which is experimentally known to activate H2 has also been considered for comparison. All the studied systems have a lower HOMO–LUMO gap than this molecule, an important factor for rendering higher reactivity. Quasiclassical trajectory for the reaction between H2 and these molecules indicates a single dynamically concerted step. Electronic structure analysis reveals synergism between donation and back donation in the activation process. The effect of substituents has also been studied which reveals that electron withdrawing substituents increase the activation barrier while electron donating substituents decrease it. The position of the substituents is also very crucial so far as the reactivity is concerned. With remote NHC stabilized boraanthracenes, it may be possible to achieve a low kinetic barrier and thermodynamic reversibility for activation of H2 .