Organometallic Chemistry

Synthesis, structure and reaction of metal carbene complexes with phosphorus centers in the carbene moiety

• Cascade rearrangements of carbene complexes leading to acyclic and cyclic isomers via P,C-bond formation
• Transformation of dinuclear carbene complexes bridged by a PR-unit into 2H-azaphosphirene complexes
• Chemistry of bis(NHC) complexes

Heterocyclic Chemistry

• Synthesis of 2H-heteroazirene containing main group 15 elements in the 2-position
• Synthesis of super-strained oxaphosphiranes and azaphosphiridines
• Synthesis of four-, five- and six-membered heterocyclic P-ligands, e.g. oxaphosphetanes, azaphosphole, diazaphosphole and polycyclic P-heterocycles
• Biradicaloid P-heterocycles

Projects:

• Electrochemical studies of P-heterocycle complexes
• SET-induced ring enlargement reactions
• Synthesis of biomimetic five-membered P-heterocycles
• Synthesis of water-soluble P-heterocycles
• Nano-sized functional P-heterocycles
• P-heterocyclic radicals
• P-heterocycles incorporating carbene centers
• Chemistry of tricyclic 1,4-phosphinines as multitopic ligands
• Chemistry of tricyclic 1,4-phosphinines as polymer building blocks

Heterocyclic Carbene Chemistry

• Synthesis of mono- and bis-(P-functional imidazole-2-ylidenes)

Chemistry of Reactive Intermediates

Generation and reactions of a wide variety of highly reactive, closed- and open-shell organophosphorus species and their use in heterocycle synthesis:

• Chemistry of electrophilic bulky-substituted terminal phosphinidene complexes
• Chemistry of novel 1,3-dipole complexes such as nitrilium phosphanylid complexes
• Chemistry of novel P-adducts of electrophilic terminal phosphinidene complexes
• Chemistry of Li/X phosphinidenoid complexes
• Chemistry of functional phosphanyl complexes
• Chemistry of phosphanoxyl complexes
• Chemistry of non-innocent P-ligands

Compliance Constants and Compliance Forces

Use of compliance constants as unique descriptors of bond strengths to predict fragmentation and rearrangement reactions of various organophosphorus and organometallic species.

• Description of very strong element-hydrogen bonds
• Organometallic complexes featuring tungsten-element single, double and triple bonds
• Organophosphorus complexes featuring phosphorus-element single, double and triple bonds

Experimental, theoretical and analytical methods:

• Organometallic syntheses (Schlenk-technique)
• Photochemical syntheses
• Ab initio and density functional calculations, compliance constants
• Application of physical analytical methods in structure determination, especially emphasizing on heteroatom-NMR spectroscopy (¹⁵N, ¹⁹F, ²⁹Si, ³¹P, ¹¹⁹Sn, ¹⁸³W), cyclo voltammetry, mass spectrometry (EI, CI, FAB), FT-IR, Raman and UV/Vis spectroscopy
• X-ray structure analysis

Research funding for Prof. Dr. Rainer Streubel (1990 to date)

Our research has received and/or receives funding from the following organizations, institutions and/or industrial partners:

1. Alexander von Humboldt Foundation: 

Feodor-Lynen Postdoctoral Fellowship for R. Streubel (1990 – 1992) 

AvH German-Ukrainian Collaborative Research Project (2009) with Dr. Igor Shevchenko: “New perspectives in methylene bis(phosphanyl) chemistry” 

AvH Awardee Reinvitation of Prof. M. Yoshifuji (2007 and 2011/2012) 

AvH Awardee Reinvitation of Prof. N. Tokitoh (2013/2014) 

AvH Awardee Reinvitation of Prof. A. J. Arduengo III (2013/2014) 

AvH Awardee Invitation (Friedrich Wilhelm Bessel-Preis) Prof. T. Sasamori (2014/2015) 

AvH Postdoc Reinvitation of Prof. R. T. Boeré (2017) 

AvH Postdoc Reinvitation of Prof. L. Nyulaszi (2017, 2019) 

AvH Awardee Invitation (J. C. Mutis Research Award) Prof. A. Frontera (2023)

2. Fonds der Chemischen Industrie: 

Habilitation (Liebig Fellowship) for R. Streubel (1992 – 1994) and various support 

Kekulé PhD Fellowship for Holger Helten (2004 – 2006) 

Fonds PhD Fellowship for Alexander Schmer (2017 – 2019) 

3. Deutsche Forschungsgemeinschaft (DFG) (Normalverfahren):

Metallaheterobutadiene (STR 411/3-1, STR 411/3-2 and STR 411/3-3) (terminated)

2H-Azaphosphirene (STR 411/6-1 and STR 411/6-2) (terminated)

Phosphanitrilylide (STR 411/9-1 and STR 411/9-2) (terminated)

Aktivierung kleiner Moleküle durch hochelektrophile Phosphorverbindungen (STR 411/25-1 und STR 411/25-2) (terminated)

„Phosphinidenoid-Metallkomplexe: Struktur, Eigenschaften und Reaktionen“ (STR 411/26-1 and STR 411/26-3) (terminated)

„Oxaphosphiran-Metallkomplexe: Synthese, Transformationen und Anwendungen“, (STR 411/29-1 and STR 411/29-3)

Umpolung of electrophilic terminal phosphinidene complexes: coordination chemistry to phosphorus and gateway to the chemistry of low-coordinate P-based super-electrophiles, (STR 411/45-1, since 2018)

Chemistry of open-shell metal complexes: Tuning spin density distributions between P-ligands and metals, (STR 411/46-1, since 2018)

Tricyclic 1,4-diphosphinines as synthetic platform for novel ligand arrays, (STR 411/49-1) (under revision)

Chemistry of ”low-coordinate 1,2-oxaphosphetanes, (STR 411/50-1) (under revision)  

Congresses and lecture tours (STR 411/11-1, STR 411/14-1, STR 411/17-1, STR 411/20-1 und DFG 411/23-1) 

DFG Priority Research Programmes 

SFB 624 “Template – Vom Design chemischer Schablonen zur Reaktionssteuerung“ (TP A3, 2005 -2009): “Templatgesteuerte Synthese polyfunktionaler N,P-Cavitanden – Struktur-/Reaktivitätsbeziehungen“ 

SFB 813 “Chemistry at Spin Centers“ (TP B4, 2009-2017): “Chemistry of Functional Phosphanyl Metal Complexes: A Combined Experimental and Theoretical Study“

DFG Collaborative Projects 

DFG German-Indian Collaborative Research Project (2009 and 2010) (STR 411/27-1) with Dr. Arif A. Khan/New Delhi: “Studies on formation, decomposition and use of transiently formed P-alkyl, P-halogeno substituted phosphane complexes” 

DFG German-Spanish Collaborative Research Project (2009 and 2010) (STR 411/28-1) with Dr. Arturo Espinosa Ferao/Murcia: “Open-shell three-membered phosphorus heterocycles: ring opening and ring expansion reactions – a combined experimental and theoretical study” 

DFG German-Kazachstan Collaborative Research Project (2011) (STR 411/30-1) with Dr. Liljia Abdrakhmanova/Kazan: “Synthesis of new O,P,C-heterocycles as potential polymer precursors”

 DFG German-Spanish Collaborative Research Project (2011) (STR 411/31-1) with Dr. Arturo Espinosa Ferao/Murcia: “Azaphosphiridine complexes: ring opening and ring expansion reactions – a combined experimental and theoretical study” 

DFG German-Spanish Collaborative Research Project (2013/2014) (STR 411/33-1) with Dr. Antonio Frontera/Palma: “Ring strain energies of biradicaloid and open-shell four-membered phosphorus heterocycles and beyond: A preparatory computational study” 

DFG German-Spanish Collaborative Research Project (2014) (STR 411/36-1) with Dr. Arturo Espinosa Ferao/Murcia: “Chemistry of thiaphosphiranes and isomers: An experimental and theoretical study”   

DFG German-Indien Collaborative Research Project (2015/2016) (STR 411/39-1) with Dr. Payal Malik: “Entwicklung und Anwendung von Li/Cl-Phosphinidenoid-Mangankomplexen in der Synthese neuartiger gespannter N,P- und S,P-heterocyclischer Liganden”   

DFG German-Japan Collaborative Research Project (STR 411/51-1), since 2019) with Prof. Dr. Takahiro Sasamori: “Synthesis of 1,4-Phosphasilabenzenes and their use in small molecule activation”   

DFG German-Indien Collaborative Research Project (STR 411/52-1, since 2019) with Assistant-Prof. Dr. Moumita Majumdar: “Tailoring tricyclic 1,4-diphosphinine for multi-stage reversible redox activity”   

DFG German-Japan Collaborative Research Project (STR 411/53-1), since 2020) with Prof. Dr. Makoto Yamashita: “Synthesis of tricyclic P/B- and P/Al-containing aromatic compounds and their potential for the activation of H2”   

4. Ministry of Culture and Research of Lower Saxony

Postdoc grant for A. A. Khan, 2001 – 2003):

„Untersuchungen zu Synthese und Reaktionen neuer fünfgliedriger N,P-Heterocyclen und deren biologischem/biokatalytischem Potential“ 

5. Technical University of Braunschweig (1992 – 2003)

Various financial support 

6. Industrial Collaborations 

Collaboration with DEGUSSA GmbH (2002 – 2003) Collaboration on the use of polycyclic P,C-cage compounds in catalysis 

Collaboration with ThermPhos International AG (December 2006 - November 2010): “Oxaphosphirane Complexes”   

7. University of Bonn 

Participation in the women mentoring program:

Maria von Linden-Program (2007/08), Support for research stay in the USA for 3 months (Aysel Özbolat) 

Maria von Linden-Program (2008/09), Support for research stay in the USA for 3 months (Janaina Marinas Pérez)) 

8. John von Neumann – Institute of Computing 

Project HBN12 (May 2003 - June 2010): “Compliance Matrizen als Hilfsmittel zur Vorhersage von Umlagerungsreaktionen molekularer Komplexe“ 

9. DAAD (German Academic Exchange Service) 

DAAD RISE Program 

(May - August 2006), Support for the research stay of K. Bentley 

(May - August 2006), Support for the research stay of H. Lee 

(May - August 2008), Support for the research stay of V. Chu 

(May-August 2008), Support for the research stay of T. Moga 

(May - August 2008), Support for the research stay of J. Arroyo 

DAAD PPP Programs 

PPP-Spain Program (Acciones Integradas Hispano Alemanas) (2006 and 2007) with Prof. Francesc Teixidor (Barcelona): “Activation of electron-rich B-H and B-I in boranes by electrophilic terminal phosphinidene complexes”. 

PPP-USA Program (2009 and 2010) with Prof. Anthony J. Arduengo III (Tuscaloosa): “Synthesis of electron-poor N-heterocyclic carbenes and metal complexes thereof”. 

PPP-Canada Program (2012 and 2013 and 2015) with Prof. Derek Gates (Vancouver): „Synthesis and reactions of backbone P-functionalized NHCs and their metal complexes”. 

PPP-Japan Program (2014 and 2015) with Prof. Norihiro Tokitoh and Prof. T. Sasamori (Kyoto): „Synthesis, bonding and reactions of heteroatom vinylidenes: new perspectives for coordination chemistry and molecular materials”. 

PPP-Japan Program (2017 and 2018) with Prof. Norihiro Tokitoh (Kyoto): „Metal com-plexes of monomolecular, anionic frustrated Lewis pairs”. 

DAAD PhD Scholarship Program 

PhD project Imtiaz Begum (since 2014): “Synthesis and reactivity studies on bis-NHCs based on new scaffolds containing P-linkers”. 

PhD project Shahriar Kermanshahian (since 2018): “Tetrathiafulvalenes fused to an aromatic or antiaromatic 1,4-diphosphinine”. 

DAAD ipid4all Program 

PhD workshop conducted by Prof. A. Frontera (2016): “Cooperativity effects between H/X-bonding interactions and π-hole based interactions” 

PhD workshop conducted by Prof. A. Espinosa Ferao (2017): “Calculation of ring strain energies” 

PhD workshop conducted by Prof. T. Sasamori (June 2019): “Chemistry of Low-coordinate Heavier Group 14 Elements” 

PhD workshop conducted by Prof. N. Tokitoh (October 2019): “In Pursuit of Unprecedented Heavier Main Group Element Compounds”

10. University of Bonn: Excellence Funding Programs 

Bonn International Fellowship for Prof. J. Protasiewicz to conduct a PhD Workshop (Case Western Reserve University, Cleveland/Ohio, USA) (funding line B: September 2020 – August 2021) 

International Collaborative Research: SDG Fellowship for Dr. Dhanushi Welideniya (Sri Lanka Institute of Nanotechnology) (funding line C: September 2020 – August 2021) 

11. International Funding Programs 

Member of the JSPS Core-to-Core Programme (2005 and 2006). 

EU COST-Program: CM0802 “PhoSciNet“ (October 2008 – March 2013):

Participant in work group 1 “Materials Science and Nanosciences” and work group 4 “Novel high potential phosphorus compounds for non-typical applications”. 

EU COST-Program: CM1302 SIPs “Smart Inorganic Polymers”, Participant in work group 1 (October 2013-March 2018). 

2019 International Collaborative Research Program of the Institute for Chemical Research, Kyoto University (with Prof. N. Tokitoh) (April 2019 – March 2020). Project code: 2019-16, title:“Small molecule activation using anionic crypto-FLPs”

 2020 International Collaborative Research Program of the Institute for Chemical Research, Kyoto University (with Prof. N. Tokitoh) (April 2020 – March 2021). Project code: 2020-??, title:“Small molecule activation using anionic crypto-FLPs” 

11. National and international collaborators since 1994 (visiting German PhD students) 

Prof. John F. Nixon (Markus Hobbold, Udo Schiemann)

Prof. F. Mathey, Paris (Nils Hoffmann)

Prof. W.W. Schoeller

Prof. A. J. Arduengo III (Hendrik Wilkens, Christoph Neumann, Susanne Sauerbrey, Lili Duan, Maren Bode, Holger Helten)

Prof. D. Gudat (Aysel Özbolat-Schön, Tobias Heurich)

Prof. F. Teixidor   (Aysel Özbolat-Schön, Maren Bode)

Prof. A. Espinosa Ferao (Philip Junker)

Prof. C. Reed (Janaina Marinas Perez, Stefan Fankel)

Prof. F. Mathey, Riverside (Aysel Özbolat-Schön)

Prof. M. Yoshifuji

Prof. C. C. Cummins (Carolin Albrecht)

Prof. N. Tokitoh  (José Manuel Villalba Franco, Andreas Kyri, Tobias Heurich, Vitaly Nesterov, Jan Faßbender, Robert Kunzmann, Philip Junker, Alexander Schmer, Niklas Volk, Florian Gleim, David Becker)

Prof. L. Nyulaszi

Prof. D. P. Gates (Paresh K. Majhi, Melina Klein, Jan Faßbender, Abhishek Koner, Imtiaz Begum)

Prof. A Espinosa Ferao (Philip Junker)

Prof. A. Frontera (Philipp Brehm, Tim Kalisch)

Prof. R. Boeré and Prof. T. Sasamori