Dick Stufkens Prize 2016 awarded to chemist Lando Wolters
Rational catalyst design through sophisticated quantum chemical calculations
The Dick Stufkens Prize 2016 for the best PhD thesis of the Holland Research School of Molecular Chemistry (HRSMC) has been awarded to Dr Lando P. Wolters. In his thesis 'Chemical Bonding and Catalysis' Wolters makes major strides towards the rational design of catalysts, which can be considered the holy grail of catalysis. Wolters will receive his prize at the annual HRSMC symposium to be held 17 November at the Gorlaeus Laboratory in Leiden.
Lando Wolters' PhD research focused on catalyst complexes consisting of atoms of transition metals combined with two 'ligand' molecules. These d10-ML2 transition metal complexes facilitate the oxidative addition process which is a key step in many catalytic conversions involved in a wide variety of applications. Examples are the synthesis of drugs and compounds for OLED displays.
Through thorough analysis of the electronic structure by means of state-of-the-art quantum chemical calculations, Wolters was able to establish the exact role of both the metal and the ligands in the performance of the catalyst complex and thus provide guidelines to predict which choice of metal and ligands will be optimal for a given catalytic conversion.
This leads to better selectivity, for example for the bond breaking of C-H versus C-C bonds, or differentiation between different C-H bonds (such as methane C-H versus ethane C-H). The overall result is a higher efficiency of the catalytic conversion.
The sophisticated quantum chemical modelling applied in Wolters' thesis consists of Kohn-Sham molecular orbital calculations (describing chemical bonding and steric effects), including relativistic effects for the heavy transition metals and the use of dispersion energies for ligand-ligand attractive interactions.
On this firm basis Wolters gives an extremely thoughtful analysis of the electronic structure, deconstructing the bond energy into its various constituents. He obtains important insights by distinguishing on the one hand the strain energy required to deform the reactants to the geometry they have in the transition state (the activation strain) and on the other hand the counteracting favorable (orbital) interactions that lower the transition state energy.
High quality work
The jury of the Dick Stufkens prize is impressed by the high quality of Wolters’ PhD thesis. He describes quite intricate bonding patterns and the role of a whole series of factors (s-bonding, π-backbonding, steric repulsion, dispersion, metal d-orbital energies, availability of metal s-orbitals, bite angle flexibility) in full detail, yet very lucidly. He summarizes his findings in easily memorizable catch phrases, such as “d-regime catalysts” and “s-regime catalysts” which show opposite dependence on ligand properties (s-donating versus π-accepting ligands). He shows the way to balance all these factors in order to achieve a specific aim, like selectivity of activation of one type of bond versus another one. Experimental groups are already applying the insights described in Wolters' thesis, demonstrating the growing impact of 'in silico' design of catalysts.
The Dick Stufkens Prize is awarded annually to the best thesis of a PhD student belonging to the Holland Research School of Molecular Chemistry (HRSMC). The prize – first awarded in 2008 - consists of a certificate and 1000 euro. Prof. Evert Jan Baerends will present the 2016 prize to the winner on 17 November on behalf of the jury during the annual HRSMC symposium held at the Gorlaeus Laboratory in Leiden.
At the symposium Lando Wolters will give a lecture on his PhD research, various HRSMC PhD students and staff members will present lectures and posters, and the 2016 Spinoza laureate Prof. Wilhelm T.S. Huck will give an invited lecture.
The HRSMC symposium is open for non-HRSMC members. Please follow the link below for programme and registration.
The Holland Research School of Molecular Chemistry was founded in 1994 and has been accredited by the Dutch Royal Academy of Arts and Sciences (KNAW). The research school combines experimental and theoretical groups working on molecular chemistry and physics from the University of Amsterdam, the VU University Amsterdam and Leiden University. Apart from creating the appropriate conditions for further collaboration between the participating groups, the school also provides an internationally highly acclaimed teaching program for PhD students. Prof. Dick Stufkens†, scientific director during the 1997-2001 period, has been one of the driving forces behind the HRSMC. His efforts have, amongst others, contributed significantly to the international reputation of the HRSMC.