Project

Keywords: Gold chemistry, Gold catalysis, NMR, DFT, Organometallic catalysis, Relativistic effects

ERC research sectors:
  • PE Physical Sciences and Engineering
  • PE4 Physical and Analytical Chemical sciences: analytical chemistry, chemical theory, physical chemistry/chemical physics (PE4_13 Theoretical and computational chemistry)
  • PE5 Materials and Synthesis: materials synthesis, structure-properties relations, functional and advanced materials, molecular architecture, organic chemistry (PE5_10 Coordination chemistry)

Background

Owing to the millenary reputation of elementary gold as the archetypal "noble", chemically inert metal, chemists were late in discovering its rich chemistry and, in particular, in observing that compounds of the type [L-Au(I)-S]X (where L is a neutral ligand, eg a phosphine or an eterocyclic carbene, and X- a weakly coordinating anion) can catalytically activate a wide range of unsaturated substrates (S) usually unreactive towards nucleophilic addition:

Since the late 80's, scientific exploration in this field has been explosively growing. Appealing features of Au(I)-based catalysis are:
  • combination of versatility and (either chemo-, regio- and/or stereo-) selectivity;
  • great operating simplicity: catalyst precursors are easily prepared and put to use;
  • "green" catalysis: only very small amounts of gold are needed; gold salts and compounds decompose often to metallic gold (that may be easily separated and recovered from the final products); the apparent insensitivity of Au to aqueous conditions allows its use in several reactions exploiting water or alcohols as "greener" solvents.

Objective

As is typical of the early life of a technology, the major aim of current research has been that of achieving know-how on an essentially empirical basis. Attempts to understand the theoretical and mechanistic foundations of this chemistry, in order for know-why to evolve alongside know-how, are scarce, not least because of the general difficulty of adequately describing heavy-metal compounds, profoundly influenced both by electron correlation and, in particular, by relativistic effects. The latter have only recently become amenable to realistic computational modeling. As a result, a reliable, undisputed, interpretive framework, in which to describe a metal-substrate bonding, is still missing.

The objective of the AuCat project is to give a significant contribution towards the understanding of the basic mechanisms, so far largely unknown, which govern the chemistry of "coinage metal" catalysts, and in particular those of Au(I) in the homogeneous phase.

Research lines

Undertaking such task with acceptable odds of success requires complementary state-of-the-art skills to be simultaneously and synergically employed along the following research lines:

  1. Synthesis and structural characterization of Au(I)-based catalytic precursors, ion-pairs resulting from their activation, and possible reaction intermediates;
  2. High Throughput Experimentation (HTE) studies of molecular kinetics of the catalytic reactions, with extensive and quantitative determination of structure-property relations;
  3. Theoretical and computational study of the observed phenomena, with realistic inclusion of relativistic effects; rationalization and generalization of computed structural and reactive properties, and feed-back on the experimental work.

Research lines 1., 2. and 3. are carried out by three cooperating Research units (RUs) based in Perugia, Napoli and Udine.