Related Experiment Video
Updated: Jun 22, 2026

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
Substituent effects on the light-induced C-C and C-Br bond activation in (bisphosphine)(eta2-tolane)Pt0 complexes. A
Daniel Escudero1, Mariana Assmann, Anne Pospiech
1Institut für Physikalische Chemie, Friedrich-Schiller-Universität, 07743 Jena, Germany.
Abstract:
A theoretical study of the steric and electronic effects of different substituents on the electronic ground and excited states of (bisphosphine)(eta2-tolane)Pt0 complexes is presented. A natural-bond-order (NBO) analysis has been performed to describe the bonding nature of the "hapto-like" coordination of the Pt atom to the alkyne bond of the tolane group. The results show an important contribution of the pi-back donation in all complexes, amounting to half of the energy associated to the sigma-bonding interaction. A TD-DFT study of the absorption spectra helps rationalizing the photochemistry of the complexes. Metal-ligand charge transfer (MLCT) transitions from the Pt atom to the alkyne are assigned as the photochemical "active" states responsible for C-C bond cleavage. Electronic excitations to the sigma* orbital of the C-Br bond are involved in C-Br bond activation. It is shown that both steric and electronic effects play an important role in determining the presence of these electronic excitations.
More Related Videos
Related Concept Videos
Directing and Steric Effects in Disubstituted Benzene Derivatives
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
π Molecular Orbitals of 1,3-Butadiene
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
π Electron Effects on Chemical Shift: Overview
Inductive Effects on Chemical Shift: Overview

