Fairlamb Research Group

Catalysis, Synthetic and Mechanistic Chemistry

Multi-Functional Ligand Design: cis- and trans-Spanning multidentate ligands

We are interested in ligand design for metal catalysis.  We have worked on alkenes, alkene-phosphine, alkene-phosphine sulfide and phosphinite ligands.  We are interested in synergic effects of different types of functionality.

Our work on dibenzylidene acetone (dba) ligands led us to design and prepare a phosphine-variant containing the dba sub-unit.   Using a straight-forward synthesis it was possible to prepare dba-phos, as a new ligand.  It is a multidentate ligand system, offering several coordination modes toward transition metals.   Some examples are given below.

The X-ray crystal structure of dba-phos is shown opposite, here in its s-cis,s-cis-conformation (around dienone moiety).  The ligand is flexible and can adopt a range of coordination modes to transition metals. 

This work was reported: Chem. Eur. J. 2013, 19, 6034.

A platinum complex showing that the dba-phos ligand can be cis-chelating (at Pt). 

A palladium complex showing that the dba-phos ligand can be trans-chelating (at Pd).

The dba-phos ligand will also bridge two palladium centres, see opposite. 

The Pd2(dba-phos)2 complex exhibits interesting chemical exchange, which was studied using dynamic NMR spectroscopic methods. 

Copyright © 2017