Prof. Dr. Dietmar Stalke

Education and Qualifications

1983                            Graduation in Chemistry and Philosophy

1987                            Dissertation: Dr. rer. nat. (University of Göttingen, Prof. U. Klingebiel)

1989                            Post-Docs: Dr. R. Snaith, Dr. P. R. Raithby, Cambridge, UK (Li chemistry) and

1991                            Prof. P. v. R. Schleyer, Erlangen, Germany (theory)

1987 - 1993                 Habilitation: venia legendi in Inorganic Chemistry (University of Göttingen, Prof. G. M. Sheldrick as the mentor)

Professional Experience

Since 2019                  Dean of Studies of the Faculty of Chemistry at the University of Göttingen

2017 - 2020                 Dean of Research of the Faculty of Chemistry at the University of Göttingen

Since 2013                  Senator of the University of Göttingen

2012 - 2015                 Dean of Studies of the Faculty of Chemistry at the University of Göttingen

2009 - 2011                 Dean of Research of the Faculty of Chemistry at the University of Göttingen

2007 - 2009                 Dean of the Faculty of Chemistry at the University of Göttingen

2005 to present           Full Professor at the University of Göttingen (W3)

1996 - 2005                 Professor at the University of Würzburg (C3)

Achievements and Honours

2017                Best lecturer of the faculty, awarded by the chemistry students at Göttingen (like in 2014, 2013 and 2009)

2017                Distinguished Visiting Professor at the IIT Bombay, India

2015                Du Pont visiting professor at the Indian Institute of Science, Bangalore, India

2015                ars legendi faculty award for excellence in university teaching

2011                Award of the Stiftungsrat der Universität Göttingen for exceptional performance in teaching by establishing the Virtual Laboratory

2005                Arfvedson-Schlenk award of the GDCh and the CHEMETALL on mayor achievements in the area of lithium chemistry

2005                Initiator and coordinator of the DFG priority program 1178 Experimental charge density determination as the key to understand chemical interactions

1987                Richard-Zsigmondy award of the faculty of chemistry at Göttingen for the best PhD thesis of the year

Publications

624           Articles in peer refereed journals

21             Book articles

9               Review articles

2               Edited books

71             total Hirsch-Index; 15 since 2017 (http://arxiv.org/abs/physics/0508025)

Scientific Interest

     Main Group Organometallics, Organolithiums, Low Valent Silicon, S- and P Centred Ligand Design, Fluorescence Chemosensors, Method Development in Low Temperature X-ray Diffraction, Experimental Charge Density Determination, (MAS) NMR Spectroscopy

Lecture 6: Dietmar Stalke

Reactivity and Bonding in Lithiumorganics from Charge Density

Dietmar Stalke

Universität Göttingen, Institut für Anorganische Chemie, Göttingen, Germany;
dstalke@chemie.uni-goettingen.de

 

Especially in the area of reactive organometallics it is essential to get information about the involved species, in the solid-state but, even more important, in solution. Since structural changes in solution like solvation and aggregation determine the reactivity and selectivity and hence the product range in organic syntheses and the materials profile. Lithiumorganics are readily applied in various preparative protocols, ranging from deprotonation of weakly acidic reagents to bond formation in organic group transfers as well as in industrial large-scale anionic polymerisation reactions. The structure-reactivity-relationship is still the Holy Grail to be found in this class of compounds because the lithiated species determine the composition, yield and stereo chemistry of the product.

Charge density investigations can provide insight into the bonding and reactivity of these labile molecules. For example, picolyllithium [(C6H6NLi·NC6H7)]2 is an excellent candidate for a detailed structure-reactivity-relationship investigation. The compound is obtained by deprotonating an excess of 2-picoline with n-butyllithium in THF and consists of a dimer with unreacted picoline as donor molecules and internal structural standard. Looking at the plain connectivities the question of whether the compound is a carbanion or a lithium amide cannot be answered decisively. The three-dimensional distribution of the electrostatic potential (ESP) provides further evidence. Opposite to the Li–N bond, we find a vast region of negative ESP above the picolyl anion plane. Areas of negative ESP are preferred reaction sites for electrophiles and indeed, an electrophilic attack on 2-picolyllithium generally occurs at the methylene group. Hence, although the Li–C bond is quite long the anion reacts as a carbanion.

  1. A. Münch, L. Knauer, H. Ott, C. Sindlinger, R. Herbst-Irmer, C. Strohmann, D. Stalke „Insight in Bonding and Aggregation of Alkyllithiums by Experimental Charge Density Studies and Energy Decomposition Analyses” J. Am. Chem. Soc. 2020, 142, 15897-15906.
  2. F. Engelhardt, C. Maaß, D. M. Andrada, R. Herbst-Irmer, D. Stalke „Benchmarking lithium amide versus amine bonding by charge density and energy decomposition analysis arguments” Chem. Sci. 2018, 9, 3111-3121.
  3. H. Ott, U. Pieper, D. Leusser, U. Flierler, J. Henn, D. Stalke „Carbanion or amide? First Charge Density Study of Parent 2-Picolyllithium" Angew. Chem. 2009, 121, 3022-3026; Angew. Chem. Int. Ed. 2009, 48, 2978-2982; classified as VIP paper and featured in a Highlight by P. Macchi in Angew. Chem. 2009, 121, 5905; Angew. Chem. Int. Ed. 2009, 48, 5793.