title: Quantifying and understanding the steric properties of N-heterocyclic carbenes.
abstract: This Feature Article presents and discusses the use of different methods to quantify and explore the steric impact of N-heterocyclic carbene (NHC) ligands. These include (a) the percent buried volume (%Vbur), which provides a convenient single number to measure steric impact and (b) steric maps, which provide a graphical representation of the steric profile of a ligand using colour-coded contour maps. A critical discussion of the scope and limitations of these tools is presented, along with some examples of their use in organometallic chemistry and catalysis. This Article should provide all users of NHCs, from organic, organometallic, and inorganic chemistry backgrounds, with an appreciation of how these tools can be used to quantify and compare their steric properties.
authors.affiliation: Organic Chemistry Institute, WWU Münster, Corrensstrasse 40, 48149 Münster, Germany.
authors.forename: Adrián
authors.identifier: http://orcid.org/0000-0003-4822-6554
authors.initials: A
authors.lastname: Gómez-Suárez
authors.affiliation: WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow, G1 1XL, UK.
authors.forename: David J
authors.identifier: http://orcid.org/0000-0002-9461-5182
authors.initials: DJ
authors.lastname: Nelson
authors.affiliation: Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent, Belgium. Steven.Nolan@UGent.be.
authors.forename: Steven P
authors.identifier: http://orcid.org/0000-0001-9024-2035
authors.initials: SP
authors.lastname: Nolan