Orbital Decomposition of the Carbon Chemical Shielding Tensor in Gold(I) N-Heterocyclic Carbene Complexes

Maria A. Izquierdo*, Francesco Tarantelli, Ria Broer, Giovanni Bistoni, Leonardo Belpassi, Remco W. A. Havenith

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
36 Downloads (Pure)

Abstract

The good performance of N-heterocyclic carbenes (NHCs), in terms of versatility and selectivity, has called the attention of experimentalists and theoreticians attempting to understand their electronic properties. Analyses of the Au(I)–C bond in [(NHC)AuL]+/0 (L stands for a neutral or negatively charged ligand), through the Dewar–Chatt–Duncanson model and the charge displacement function, have revealed that NHC is not purely a σ-donor but may have a significant π-acceptor character. It turns out, however, that only the σ-donation bonding component strongly correlates with one specific component of the chemical shielding tensor. Here, in extension to earlier works, a current density analysis, based on the continuous transformation of the current density diamagnetic zero approach, along a series of [(NHC)AuL]+/0 complexes is presented. The shielding tensor is decomposed into orbital contributions using symmetry considerations together with a spectral analysis in terms of occupied to virtual orbital transitions. Analysis of the orbital transitions shows that the induced current density is largely influenced by rotational transitions. The orbital decomposition of the shielding tensor leads to a deeper understanding of the ligand effect on the magnetic response properties and the electronic structure of (NHC)-Au fragments. Such an orbital decomposition scheme may be extended to other magnetic properties and/or substrate-metal complexes.

Original languageEnglish
Pages (from-to)1177-1183
Number of pages7
JournalEuropean Journal of Inorganic Chemistry
Volume2020
Issue number13
DOIs
Publication statusPublished - 7-Apr-2020

Keywords

  • Carbene ligands
  • Gold
  • Chemical shielding tensor
  • Electron donation
  • Electron back-donation
  • C-13 NMR-SPECTROSCOPY
  • CONTINUOUS TRANSFORMATION
  • CAPTIVE INTERMEDIATE
  • MAGNETIC-PROPERTIES
  • RING CURRENTS
  • BOND
  • APPROXIMATION
  • PATTERNS
  • GROUP-11
  • DONATION

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