Stefan KNIPPENBERG

Stefan Knippenberg completed his Ph.D. at Hasselt University in Belgium in 2007, where his research centered on simulating ionization events in medium-sized molecules using the Algebraic Diagrammatic Construction (ADC) framework. During his time as an Alexander von Humboldt Fellow in Germany, he expanded his research to include nonlinear optical effects analyzed through correlated methods. As a Marie Curie Fellow at Mons University in Belgium, he developed an interest in how light-sensitive molecules interact with biological environments. Following a postdoctoral position as a “Chargé de Recherches” in Liège, Belgium, Stefan relocated to Sweden, where he founded an initial research group at the KTH Royal Institute of Technology. He is currently back in Belgium, focusing largely on molecular interactions and multiscale modeling of soft-matter systems.

Academic employment history - Curriculum Vitae

September 2019 - …: Theory Lab, Hasselt University
Research fields: lipid bilayers, non-linear optics, fluorescence
March 2019 – December 2019: Research associate, Regional Centre of Advanced Technologies and Materials, Palacký University, Olomouc, Czech Republic
Research field: fluorescent probes; [100% March – May, 20% June – December]
June 2019 – August 2019: Research associate, Department of Chemistry, University of Antwerp (Belgium)

September 2018 – February 2019: Research associate, Biomedical Research Center, Hasselt University
September 2014 – August 2018: Biträdande Lektor / Assistant Professor, Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, Stockholm (Sweden).
Research fields: non-linear optics, cyanines, fluorescence anisotropy, lipid bilayer membranes
May 2013 – August 2014: Fellow of the Fonds National de la Recherche Scientique (FNRS), Chargé de Recherches, group of Prof. Dr. F. Remacle, Theoretical Physical Chemistry, Université de Liège.
Research fields: photoionization and –dissociation in strong and rapidly changing electric fields, spectroscopy, optical probes.
- 16 August 2013 – 15 September 2013: Group of Prof. Dr. E. J. Baerends, Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit Amsterdam (The Netherlands).
  Research fields: time dependent density matrix functional theory.
- January 2014: Group of Prof. Dr. P. Trouillas, INSERM UMR850, Faculté de Pharmacie,
  Limoges (France)
  Research fields: lipid bilayer membranes, molecular dynamics.

February 2013 – April 2013: Fellow of the Alexander von Humboldt foundation, group of Prof. Dr. Andreas Dreuw, Theoretical and Computational Chemistry, Interdisciplinary center for scientific computing, Universität Heidelberg (Germany).
Research field: hyperpolarisabilities.

February 2011 – January 2013: Fellow of Marie Curie COFUND and the Belgian Science Policy Office (Belspo), group of Prof. Dr. R. Lazzaroni, Prof. Dr. D. Beljonne and Prof. Dr. J. Cornil, Laboratory for Chemistry of Novel Materials, Université de Mons (Belgium).
Research fields: optical probes, biomembranes, lipid rafts, DNA.
- January 2013 and 26 February – 23 March 2012: Group of Prof. Dr. P. Trouillas, Laboratoire de chimie des substances naturelles, Faculté de Pharmacie, Limoges (France)
  Research fields: lipid bilayer membranes, molecular dynamics.
- September 2012 – December 2012: Group of Prof. Dr. J.-L. Brédas, School of chemistry and biochemistry, Georgia Institute of Technology, Atlanta (United States of America)
  Research fields: second and third hyperpolarizabilities, cyanines.
- September 2011 – December 2011: Group of Prof. Dr. E. J. Baerends, Department of Chemistry, Pohang University of Science and Technology, Pohang (South Korea)
  Research fields: time dependent density matrix functional theory.

October 2007 – January 2011: Fellow of the Alexander von Humboldt foundation, group of Prof. Dr. Andreas Dreuw, Institute of Physical and Theoretical Chemistry, Goethe-Universität Frankfurt am Main (Germany).
Research fields: excitation, two-photon absorption, algebraic diagrammatic construction scheme, time dependent density functional theory.

October 2003 – September 2007: Ph. D. fellowship, research group Theoretical Chemistry, department SBG, Hasselt University (Belgium)

Studies

2014-2017: Swedish diploma of ‘Docent i teorisk fotokemi och fotobiologi’ (15 March 2017). Pedagogical training of 15 cpts in higher education focusing on Ph.D. supervision, supervision on degree project work in bachelor and master studies, assessment criteria and undergraduate teaching (KTH Royal Institute of Technology, Stockholm, Sweden; certificate: 26 November 2015).
2003-2007: Ph.D. in Chemical Physics at Hasselt University (Belgium)
Date of defence: 1^st October 2007; supervisors: Prof. Dr. M. S. Deleuze and Prof. Dr. J.-P. François
Title: “Green's function and Dyson orbital studies of the electronic structure of cage compounds and flexible molecules: a confrontation of many-body quantum mechanics with electron momentum, photo-electron and Penning ionization electron spectroscopies”. Specialization courses in chemical bonding, spectroscopic techniques and computational methods at the Katholieke Universiteit Leuven (Belgium).

2001-2003: Master student in Physics at the Katholieke Universiteit Leuven (Belgium)
Master’s thesis in Theoretical Physics (High Energy Physics): “p-branen in supergravitatie: veralgemeningen naar oplossingen met een kosmologische constante”. Supervisors: Dr. B. Janssen and Prof. Dr. W. Troost.

Prizes and awards

2 May 2008: “Honorable Mention Award” in the “2008 IUPAC Prize for Young Chemists”

Spring 2015: Obtained grant from Vetenskapsrådet, Sweden, to organize the EJTEMM meeting

14 June 2023: “Assucopie award for the publication and illustration of educational and scientific works”

Jury

2 times Opponent in PhD defense, 1 time PhD Jury member, 1 time PhD mid-term (Swedish ‘Licentiat’) Jury member

Scientific services

Main organizer of the 3^rd European Joint Theory Experiment Meeting on Membranes (30 Sept-2 Oct 2015)

Chair of scientific committee of the Joint Theory Experiment Meeting on Membranes conference series: https://www.ejtemm.eu

Member of the social media team of the german Arbeitsgemeinschaft Theoretische Chemie (agTC)

Member of the selection committee of the theoretical section of the Swedish Chemical Society (2015-2018)

Visits to foreign research groups

Visits to groups in Poland, France, Germany and China

Referee

Referee assignments for research projects of “Fondation pour la Recherche en Chimie” (France), “Emergence” (France) and “Fonds voor Wetenschappelijk Onderzoek” (Belgium); Referee assignments for J. Am. Chem. Soc., Phys. Chem. Chem. Phys., Pharmacol. Res., …

Teaching experience and supervision

Hasselt University: teaching assistant in master courses 'Grant proposal writing' and 'Theory in Soft Matter'; supervisor of bachelor thesis

KTH Royal Institute of Technology: teacher in courses “Molecular Modelling”, “Programming in Python” and “Fysikalisk Biokemi”, supervisor of post-docs, supervisor of bachelor theses

Goethe Universität Frankfurt: Teaching assistant in 'Thermodynamik und Elektrochemie', 'Quantenmechanik' and 'Molekulare Spektroskopie'; supervising tutor of internships, bachelor theses and PhD student (8 months)

Languages

Dutch (mother tongue), English & French (full working proficiency), German (talking/reading), Swedish (higher intermediate)

Memberships

            Fakultetskollegium at KTH Royal Institute of Technology, CoTXS network, Belgian Interuniversity Attraction Pole
            Functional Supramolecular Systems, Belgian Physical Society, American Chemical Society, Biophysical Society,
            Belgian Biophysical Society, german DGfB, COST actions CoDECS and Xlic

Leisure time

Youth movement group interested in astronomy, hiking, brassband

Publications

Identifiers: Orcid.org/0000-0002-4527-2566; ResearcherID: L-3452-2013

A. P. Sgouros, S. Knippenberg, A. Bocahut, P. M. Rauscher, B. Sikora, S. Caputo, H.-S. Choi, V. Finsy, M. Guillaume, D. Theodorou, "Mesoscale modelling of polymer-mediated adhesion: application to tack tests", Mol. Sys. Des. Eng. (2025), doi:10.1039/D4ME00199K
S. Osella, S. Knippenberg, “Photophysics in Biomembranes: Computational insight into the interaction between lipid bilayers and chromophores”, Acc. Chem. Res. 57 (2024), 2245
S. Knippenberg, K. De, C. Aisenbrey, B. Bechinger, S. Osella, "Hydration- and Temperature-Dependent Fluorescence Spectra of Laurdan Conformers in a DPPC Membrane", Cells 13 (2024), 1232 - contribution to the special issue 'Advances in Biophysics of Cellular Membranes', Eds. P. V. Nagy, G. Vamosi
M. Bacalum, M. Radu, S. Osella, S. Knippenberg, M. Ameloot, "Generalized Polarization and time-resolved fluorescence provide evidence for different populations of Laurdan in lipid vesicles", J. Photochem. Photobiol. B (2023), doi: 10.1016/j.jphotobiol.2023.112833
S. Osella, G. Grannucci, M. Persico, S. Knippenberg, “Dual photoisomerization mechanism of azobenzene embedded in a lipid membrane”, J. Mat. Chem. B (2023), DOI: 10.1039/D2TB02767D
N. P. Benetis, M. Paloncýová, S. Knippenberg, "Multiscale Modeling Unravels the Influence of Biomembranes on the Photochemical Properties of Embedded Anti-Oxidative Polyphenolic and Phenanthroline Chelating Dyes", J. Phys. Chem. B 127 (2023), 2012
S. Osella, M. Marczak, N. Arul Murugan, S. Knippenberg, "Exhibiting environment sensitive optical properties through multiscale modelling: a study of photoactivatable probes", J. Photochem. Photobiol. A (2021), doi: 10.1016/j.jphotochem.2021.113672
A. Sgouros, S. Knippenberg, M. Guillaume, D. Theodorou, "Multiscale simulations of polyzwitterions in aqueous bulk solutions and brush array configurations", Soft Matter (2021), doi: 10.1039/D1SM01255J
S. Osella, S. Knippenberg, "The influence of lipid membranes on fluorescent probes’ optical properties", BBA Biomembranes 1863 (2021), 183494 - Minireview on invitation
S. Osella, M. Paloncýová, M. Sahi, S. Knippenberg, "Influence of Membrane Phase on the Optical Properties of DPH", Molecules 25 (2020), 4264 - contribution to the special issue 'Membrane Structure and Function', Eds L. M. S. Loura, M. J. Moreno, A. Jawhari
S. Knippenberg, S. Osella, "Push/Pull Effect as Driving Force for Different Optical Responses of Azobenzene in a Biological Environment" J. Phys. Chem. C 124 (2020), 8310
M. Paloncýová, J. Tornmalm, S. Sen, J. Piguet, J. Widengren, S. Knippenberg, "The Photoisomerization of DiD: Molecular Dynamics Calculations Reveal the Influence of the Tail Lengths", J. Phys. Chem. C. 124 (2020), 5829
S. Osella, S. Knippenberg, "Laurdan as Molecular Rotor in Biological Environments", ACS Appl. Bio Mater. 2 (2019), 5769
S. Osella, N. Smisdom, M. Ameloot, S. Knippenberg, "Conformational Changes as Driving Force for Phase Recognition: The Case of Laurdan", Langmuir 35 (2019), 11471
M. Paloncýová, G. Aniander, E. Larsson, S. Knippenberg, "Cyanine dyes with tail length asymmetry enhance photoselection: a multiscale study on DiD probes in a liquid disordered membrane", Spectrochim. Acta A 224 (2020), 117329
M. Paloncýová, M. Ameloot, S. Knippenberg, "Orientational Distribution of DPH in Lipid Membranes: a Comparison of Molecular Dynamics Calculations and Experimental Time-Resolved Anisotropy Experiments", Phys. Chem. Chem. Phys., 21 (2019), 7594
S. Osella, S. Knippenberg, "Environmental Effects on the Charge Transfer Properties of Graphene Quantum Dot Based Interfaces", Int. J. Quant. Chem. (2018), e25882.
S. Osella, F. Di Meo, N. Arul Murugan, G. Fabre, M. Ameloot, P. Trouillas, S. Knippenberg, "Combining (Non-) Linear Optical and Fluorescence Analysis of DiD to Enhance Lipid Phase Recognition", J. Chem. Theory Comput. 14 (2018), 5350.
S. Knippenberg, G. Fabre, S. Osella, F. Di Meo, M. Paloncýová, M. Ameloot, P. Trouillas, "Atomistic picture of fluorescent probes with hydrocarbon tails in lipid bilayer membranes: an investigation of selective affinities and fluorescent anisotropies in different environmental phases", Langmuir 34 (2018), 9072.
S. Osella, S. Knippenberg, "Triggering On/Off States of Photoswitchable Probes in Biological Environments", J. Am. Chem. Soc. 139 (2017), 4418.
S. Osella, N. A. Murugan, N. K. Jena, S. Knippenberg, “Linear and Nonlinear optical properties of Laurdan and C-laurdan probes in a DOPC membrane”, J. Chem. Theory Comput. 12 (2016), 6169.
S. Knippenberg, R. L. Gieseking, D. R. Rehn, S. Mukhopadhyay, A. Dreuw, J.-L. Brédas, “Benchmarking Post-Hartree–Fock Methods To Describe the Nonlinear Optical Properties of Polymethines: An Investigation of the Accuracy of Algebraic Diagrammatic Construction (ADC) Approaches”, J. Chem. Theory Comput. 12 (2016), 5465.
M. Bacalum, L. N. Wang, S. Boodts, P. J. Yuan, V. Leen, N. Smisdom, E. Fron, S. Knippenberg, G. Fabre, P. Trouillas, D. Beljonne, W. Dehaen, N. Boens, M. Ameloot, “A blue-light-emitting BODIPY probe for lipid membranes”, Langmuir 32 (2016), 3495.
J. Rubio-Magnieto, E. Gebremedhn Azene, J. Knoops, S. Knippenberg, C. Delcourt, A. Thomas, S. Richeter, A. Mehdi, P. Dubois, R. Lazzaroni, D. Beljonne, S. Clément, M. Surin, “Self-assembly and hybridization mechanisms of DNA with cationic polythiophene”, Soft Matter 11 (2015), 6460.
S. Knippenberg, M. V. Bohnwagner, P. H. P. Harbach, A. Dreuw, “Strong electronic coupling dominates the absorption and fluorescence spectra of covalently bound BisBODIPYs”, J. Phys. Chem. A 119 (2015), 1323.
S. Knippenberg, B. Hajgató, “The cage fragmentation of doubly ionized norbornane: a Born-Oppenheimer molecular dynamics study”, Chem. Phys. Lett. 584 (2013), 24.
M. Kirkus, S. Knippenberg, D. Beljonne, J. Cornil, R. A. J. Janssen, S. C. J. Meskers, ”Synthesis and optical properties of pyrrolo[3,2-b]pyrrole-2,5(1H,4H)-dione (iDPP) based molecules”, J. Phys. Chem. A. 117 (2013), 2782.
S. Knippenberg, M. Scheider, P. Mangal, A. Dreuw, “The molecular mechanism of photochromism in photo-enolizable quinoline and napthyridine derivatives”, J. Phys. Chem. A 116 (2012), 12321.
A. Dreuw, M. Polkehn, R. Binder, A. Heckel, S. Knippenberg, “Computational design of caging compounds based on nitrodibenzofuran with increased two-photon absorption”, J. Comp. Chem. 33 (2012), 1797.
S. Knippenberg, D. R. Rehn, M. Wormit, J. H. Starcke, I. L. Rusakova, A. B. Trofimov, A. Dreuw, “Calculations of nonlinear response properties using intermediate state representation and algebraic diagrammatic construction polarization propagator approach: Two-photon absorption spectra”, J. Chem. Phys. 136 (2012), 064107.
S. Knippenberg, B. Hajgató, “The band 12 issue of norbornane: a study of higher shake-up states”, Spectrochim. Acta A 88 (2012), 102.
S. Knippenberg, P. Eisenbrandt, L. Sistik, P. Slavicek, A. Dreuw, “Simulation of photoelectron spectra using the reflection principle in combination with unrestricted excitation ADC(2) to assess the accuracy of excited state calculations”, Chem. Phys. Chem. 12 (2011), 3180.
S. Knippenberg, M. Kunitski, A. Dreuw, “Large amplitude motions in cyclopentene and 1-butene: quantum chemical insights into the ground- and excited state potential energy surfaces”, Z. Phys. Chem. 225 (2011), 525.
S. Knippenberg, J. H. Starcke, M. Wormit, A. Dreuw, “The low-lying excited states of neutral polyacenes and their radical cations: a quantum chemical study employing the algebraic diagrammatic construction scheme of second order“, Mol. Phys. 108 (2010), 2801.
M. Kunitski, S. Knippenberg, A. Dreuw, B. Brutschy, “The conformational stability of gaseous 1-butene studied by femtosecond nonlinear spectroscopy and ab initio calculations”, Vib. Spectrosc. 56 (2010), 13.
F. Morini, S. Knippenberg, M. S. Deleuze, B. Hajgató, “Quantum chemical study of conformational fingerprints in the photoelectron spectra and (e,2e) electron momentum distributions of n-hexane”, J. Phys. Chem. A. 114 (2010), 4400-4417.
M. Kunitski, S. Knippenberg, M. Gelin, C. Riehn, A. Dreuw, B. Brutschy, “Ring puckering motion in cyclopentene studied by time-resolved rotational coherence spectroscopy and ab initio calculations”, Phys. Chem. Chem. Phys. 12 (2010), 8190-8200.
M. S. Deleuze, B. Hajgató, F. Morini, S. Knippenberg, “Probing electron correlation and nuclear dynamics in momentum space”, J. Phys.: Conf. Ser. 212 (2010), 012020.
S. Knippenberg, M. S. Deleuze, “Correlation effects in the valence ionization spectra of large conjugated molecules: p-Benzoquinone, anthracenequinone and pentacenequinone”, J. Electron Spectrosc. Relat. Phenom. 178 (2010), 61.
C. G. Ning, B. Hajgató, Y. R. Huang, S.F. Zhang, K. Liu, Z.H. Luo, S. Knippenberg, J. K. Deng, M. S. Deleuze, “High resolution electron momentum spectroscopy of the valence orbitals of water”, Chem. Phys. 343 (2008), 19-30.
S. Knippenberg, Y. R. Huang, B. Hajgató, J.-P. François, M. S. Deleuze, “Probing molecular conformations in momentum space: the case of n-pentane”, J. Chem. Phys. 127 (2007), 174306.
S. Knippenberg, B. Hajgató, J.-P. François, M. S. Deleuze, “Theoretical study of the fragmentation pathways of norbornane in its doubly ionized ground state”, J. Phys. Chem. A 111, (2007), 10834-10848.
Y. R. Huang, S. Knippenberg, B. Hajgató, J.-P. François, J. K. Deng, M. S. Deleuze, “Imaging momentum orbital densities of conformationally versatile molecules: a benchmark theoretical study of the molecular and electronic structures of dimethoxymethane”, J. Phys. Chem. A 111 (2007), 5879-5897.
M. S. Deleuze and S. Knippenberg, “Study of the molecular structure, ionization spectrum and electronic wave function of 1,3-butadiene using electron momentum spectroscopy and benchmark Dyson orbital theories”, J. Chem. Phys. 124 (2006), 104309.
S. Knippenberg, J.-P. François, M. S. Deleuze, “Green's function study of the one-electron and shake-up ionisation spectra of unsaturated hydrocarbon cage compounds”, J. Comp. Chem. 27 (2006), 1703-1722.
C. G. Ning, X. G. Ren, J. K. Deng, G. L. Su, S. F. Zhang, S. Knippenberg, M. S. Deleuze, “Probing Dyson orbitals with Green’s function theory and electron momentum spectroscopy”, Chem. Phys. Lett. 421 (2006), 52-57.
N. Kishimoto, Y. Hagihara, K. Ohno, S. Knippenberg, J.-P. François, M. S. Deleuze, “Probing the shape and stereochemistry of molecular orbitals in locally flexible aromatic chains: a Penning ionization electron spectroscopy and Green’s function study of the electronic structure of biphenyl”, J. Phys. Chem. A 109 (2005), 10535-10546.
S. Knippenberg, K. L. Nixon, H. Mackenzie-Ross, M. J. Brunger, F. Wang, M. S. Deleuze, J.-P. François and D. A. Winkler, “Investigation into the valence electronic structure of norbornene using electron momentum spectroscopy, Green’s function and density functional theories”, J. Phys. Chem. A 109 (2005), 9324-9340.
S. Knippenberg, M. S. Deleuze, T. J. Cleij, J.-P. François, L. S. Cederbaum, J. H. D. Eland, “The band 12 issue in the electron momentum spectra of norbornane: A comparison with further Green’s function calculations and ultra-violet photoemission measurements”, J. Phys. Chem. A 109 (2005), 4267-4273.
S. Knippenberg, K. L. Nixon, M. J. Brunger, T. Maddern, L. Campbell, N. Trout, F. Wang, W. R. Newell, M. S. Deleuze, J.-P. François, D. A. Winkler, “Norbornane: An investigation into its valence electronic structure using electron momentum spectroscopy, and density functional and Green’s function theories”, J. Chem. Phys. 121 (2004), 10525-10541.

dr. Stefan KNIPPENBERG

About Me

Research

Publications

Projects

Non-linear optical and time-dependent fluorescence properties of molecular probes reveal the phases of surrounding lipid membranes: a multiscale modeling approach (Research)

Non-linear optical and time-dependent fluorescence properties of molecular probes reveal the phases of surrounding lipid membranes: a multiscale modeling approach (Research)

Computational modeling reveals the influence of lipid membrane phases on fluorescent probes' optical properties (Research)

Using non-linear optical properties of conjugated probes to investigate biological environments: the DPH and DiD probes embedded in various lipid bilayers and GUVs (Research)