Related Experiment Video
Updated: Feb 14, 2026

Scanning-probe Single-electron Capacitance Spectroscopy
Published on: July 30, 2013
Exploiting coordination geometry to selectively predict the σ-donor and π-acceptor abilities of ligands: a
Marco Fusè1, Isabella Rimoldi2, Giorgio Facchetti2
1Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy. sergio.rampino@sns.it.
Abstract:
Through an analysis of eighty tetrahedral and square-planar metal carbonyls of general formula [M(CO)(L')(L)2] including newly synthesized chlorocarbonyl rhodium complexes with chelating atropoisomeric diphosphanes, we show how coordination geometry can switch the carbonyl stretching frequency into a selective probe of the σ-donor and π-acceptor abilities of the ligands. We thus provide a framework whereby the σ-donation and π-backdonation constituents of the Dewar-Chatt-Duncanson model can be quantitatively predicted through spectroscopic data on coordinated CO moieties and vice versa.
Related Concept Videos
Coordination Number and Geometry
Predicting Molecular Geometry
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Coordination Compounds and Nomenclature
π Electron Effects on Chemical Shift: Overview

