Quantum Chemical Investigation of the Structure and Reactivity of Indole Derivatives of Tricarbonylchromium(0)

Abstract

~ ~~~In a theoretical investigation of the structure and reactivity of indole derivatives 6f tricarbonylchromium(O), we have used two different semi-empirical quantum chemical models derived from the extended Huckel molecularorbital (EHMO) formalism. The first one, based on the atom-superposition and electron-delocalization (ASED) method, is used to optimize the geometry of the systems; it is shown to lead to results in satisfactory agreement with experiment in the case of the complex for which X-ray structural data are available, the average errors being 0.034.05 A for bond distances and 5" for bond angles. The second one consists of a local reactivity index, made of the intermolecular interaction energy between the organometallic substrate and a model reactant. It is seen that this procedure is able to reproduce the experimental trends as to the most reactive regions of the systems investigated towards nucleophilic and electrophilic addition reactions.

Reactivity of (η6-Arene)tricarbonylchromium Complexes toward Additions of Anions, Cations, and Radicals

“…They commented that a small electrophile like a proton should add directly to the metal. Weber and co-workers used semiempirical quantum chemical methods derived from extended Hückel molecular orbital theory to examine nucleophilic addition reactions to indole complexes and were able to reproduce experimental trends . Recently, Koga and co-workers employed HF, B3LYP, and MP2 levels of theory to study molecular electrostatic potentials and electron density topographies of arene chromium complexes 27a.…”