On the nature of spin- and orbital-resolved Cu –NO charge transfer in the gas phase and at CuI sites in zeolitesReport as inadecuate




On the nature of spin- and orbital-resolved Cu –NO charge transfer in the gas phase and at CuI sites in zeolites - Download this document for free, or read online. Document in PDF available to download.

Structural Chemistry

, Volume 23, Issue 5, pp 1349–1356

First Online: 06 June 2012Received: 17 July 2011Accepted: 20 December 2011

Abstract

Electronic factors essential for NO activation by CuI sites in zeolites are investigated within spin-resolved analysis of electron transfer channels natural orbitals for chemical valence. NOCV analysis is performed for three DFT-optimized models of CuI–NO site in ZSM-5: CuNO, T1CuNO, and M7CuNO. NO as a non-innocent, open-shell ligand reveals significant differences between independent deformation density components for α and β spins. Four distinct components are identified: i unpaired electron donation from NO π‖* antibonding orbital to Cus,d; ii backdonation from copper dyz to π⊥* antibonding orbital; iii donation from occupied π‖ and Cu dxz to bonding region, and iv donation from nitrogen lone-pair to Cus,d. Channel i, corresponding to one-electron bond, shows-up solely for spin majority and is effective only in the interaction of NO with naked Cu. Channel ii dominates for models b and c: it strongly activates NO bond by populating antibonding π* orbital and weakens the N–O bond in contrast to channel i, depopulating the antibonding orbital and strengthening N–O bond. This picture perfectly agrees with IR experiment: interaction with naked Cu imposes small blue-shift of NO stretching frequency while it becomes strongly red-shifted for CuI site in ZSM-5 due to enhanced backdonation.

KeywordsNO activation CuI sites Charge transfer Donation and backdonation Natural orbitals for chemical valence Electronic supplementary materialThe online version of this article doi:10.1007-s11224-012-0050-y contains supplementary material, which is available to authorized users.

Download fulltext PDF



Author: P. Kozyra - M. Radon - J. Datka - E. Broclawik

Source: https://link.springer.com/







Related documents