Development of Carbene Stabilized Gold Nanoparticles

時間地點:10:00 am, Apr 11 (Tue), 2023; R1-B1122 Conference Room

研討講者:Michael Reithofer, Ph.D.

April 06, 2023


In the quest to develop highly stable nanoparticles, N-heterocyclic carbenes (NHC) have emerged as an alternative to thiol-based ligands for stabilizing metal nanoparticles (NPs), as the metal-NHC bond is usually much stronger than the corresponding metal-thiol bond. This should result in more stable NPs which are less susceptible to ligand exchange reactions. Over the last decade an increasing number of NHC stabilized NPs have been reported and significant effort was made in utilizing these compounds, such as for bioimaging, sensing and also heterogeneous catalysis.1 

We are interested in NHC-stabilized AuNPs whereby the NHC is derived from the natural chiral pool.2,3  For this, L and D- histidine was converted into its imidazolium salt using methyl iodine. Subsequent reaction with Ag2O followed by the addition of [Au(SMe2)Cl] yields the corresponding organometallic gold chloride complex, which can subsequently be reduced to histidine-2-ylidene stabilized AuNPs. Due to the chiral nature of histidine, dichroic effects can be detected in circular dichroism spectroscopy. Further water-soluble and pH-responsive histidine-2-ylidene stabilized AuNPs can be obtained through a free unprotected C-terminus of the employed histidine.4

This talk will also touch on the first examples of protic acyclic diamino carbene stabilized AuNPs (ADCAuNPs).5 Compared to NHCs, which are often challenging to asymmetrically functionalize, ADCs have high synthetic flexibility allowing not only the fine adjustment of steric and electronic properties, but also the ease of access of non-symmetric substitutions. Through a series of ADC-stabilized AuNPs, we demonstrate that ADC can be an alternative to NHCs to access functionalized carbene-stabilized AuNPs, with comparable stability but often better structural flexibility.  


Financial support by the University of Vienna is gratefully acknowledged. This work was supported by the Austrian Science Fund (FWF) Stand-alone grant no. P-34662


1. Eisen, C.; Chin, J. M.; Reithofer, M. R. Catalytically Active Gold Nanomaterials Stabilized by N ‐heterocyclic Carbenes. Chem. Asian J. 2021, 16 (20), 3026-3037.

2. Young, A. J.; Serpell, C. J.; Chin, J. M.; Reithofer, M. R. Optically active histidin-2-ylidene stabilised gold nanoparticles. Chem. Commun. 2017, 53 (92), 12426-12429, 10.1039/C7CC07602A.

3. Young, A. J.; Sauer, M.; Rubio, G. M. D. M.; Sato, A.; Foelske, A.; Serpell, C. J.; Chin, J. M.; Reithofer, M. R. One-step synthesis and XPS investigations of chiral NHC–Au(0)/Au(i) nanoparticles. Nanoscale 2019, 11 (17), 8327-8333, 10.1039/C9NR00905A.

4. Young, A. J.; Eisen, C.; Rubio, G. M. D. M.; Chin, J. M.; Reithofer, M. R. pH responsive histidin-2-ylidene stabilized gold nanoparticles. J. Inorg. Biochem. 2019, 199, 110707.

5. Rubio, G.; Keppler, B. K.; Chin, J. M.; Reithofer, M. R. Synthetically Versatile Nitrogen Acyclic Carbene Stabilized Gold Nanoparticles. Chem. Eur. J. 2020, 26 (68), 15859-15862.

Michael Reithofer, Ph.D.

Institute of Inorganic Chemistry

University of Vienna

Michael Reithofer, Ph.D.

Associate Professor 

Institute of Inorganic Chemistry,

University of Vienna, Austria

2016 – 2017 Postgraduate Certificate in Academic Practice, University of Hull
2008 – 2010 Postdoctoral Fellow
Massachusetts Institute of Technology, Department of Chemistry, United States of 
Supervisor: Nobel Prize Laureate Professor Richard R. Schrock 
2006 – 2008 PhD in Chemistry
University of Vienna 
Thesis: Development of Novel Anticancer Platinum(IV) Complexes:
Synthesis, Characterization and Cytotoxic Properties
Supervisor: Professor Dr. Dr. Bernhard K. Keppler
2000-2005 Chemistry studies, University of Vienna.

Current position
2018 – Present Associate Professor at the Institute of Inorganic Chemistry, University of Vienna

Previous positions
2017 – 2018 Assistant Professor at the Institute of Inorganic Chemistry, University of Vienna 
2014 – 2017 Lecturer in Organic Chemistry with tenure, School of Mathematics and Physical Sciences,                                University of Hull, United Kingdom. 
2010 – 2014 Research Scientist, Institute of Bioengineering and Nanotechnology, A-STAR, Singapore. 
2006 – 2008 Teaching Assistant (Assistent in Ausbildung), Institute of Inorganic Chemistry, University of Vienna.

Awards and prizes
1. 2012 Team Winner of the Agency for Science Technology and Research Young Researcher 
Collaborative Grant competition 
2. 2012 Peoples’ Choice Award Winner Agency for Science Technology and Research Young 
Researcher Collaborative Grant competition
3. 2008 Award of Excellence for outstanding Ph.D. research, Austrian Federal Ministry of 
Science and Research.