Nicolas Bréfuel

Senior chemical engineer

Centre d’Elaboration des Matériaux et d’études Structurales, CEMES UPR 8011


+033 5 62 25 78 30 / +033 6 62 94 48 97


2004     Doctor in « Physical and chemical properties of molecular magnetic materials », Toulouse University

2001     Master’s degree « Coordination Chemistry », Toulouse University


Research function / teaching activityLaboratory / Research teamPeriod
Senior chem. engineer – On surface chemistry : Synthesis of planar-conjugated organic molecules and nanocars

CEMES – UPR 8011 (Toulouse)

Groupe Nanoscience

Senior chem. engineer – Switchable dielectric molecular materials

G2Elab – UMR 5269 (Grenoble)

Equipe Matériaux Diélectriques et Electrostatique

01/09/2018- 31/08/2022
Senior chem. engineer – Bistable porous molecular materials for gaz storage

LFCR – UMR 5150 (Bayonne)

Equipe G2MP Géomécanique Milieux Poreux

01/01/2018 – 31/08/2018

Senior Scientific and technological watch coordinator  Molecular and organic electronics, nanocontruction

OMNT – UMS 2920 (CEA MINATEC Grenoble)

Observatoire des Micro et Nano Technologies

01/09/2012 – 31/12/2017
Chemical engineer Fixed-term contract– Magnetic organic radicals

LNCMI – UPR 3228 (Grenoble)

Equipe Magnétisme Moléculaire et RPE

01/09/2008 – 30/11/2011
Assistant professor (ATER) – Bordeaux University /  Molecular magnet chains

CRPP – UMR 5031 (Bordeaux)

Equipe Matériaux Moléculaires et magnétisme

01/09/2007 – 31/08/2008
Assistant professor (ATER) – Toulouse University  / Molecular magnets based on heptacyanide building blocks

LCC – UPR 8241 (Toulouse)

Equipe Matériaux moléculaires et supramoléculaires

01/09/2006 – 31/08/2007
Post-doctorate (JSPS funding) / Bio-inspired Photoswitchable spin transition complexes

Kumamoto University (Japan)

Faculty of chemistry

15/11/2004 – 30/06/2006
Chemical engineer Fixed-term contract – Mössbauer spectroscopy of spin transition complexes

LCC – UPR 8241 (Toulouse)

Equipe Chimie Bioinorganique et matériaux biomimétiques

01/10/2004 – 14/11/2004
PhD  / Spin transition materials, physical and synthetic approaches

LCC – UPR 8241 (Toulouse)

Equipe Chimie Bioinorganique et matériaux biomimétiques

01/10/2001 – 30/09/2004





Organic (ligands) and inorganic (complexes) chemical synthesis, under controlled atmosphere

Vacuum line, Schlenck tubes, glove box

Preparation and shaping in the form of composites in polymers or Nanoparticles or thin films

Magnetic measurements

SQUID Susceptometer

Temp. or magnetic field dependant measurements

XRD on single crystals or powders or thin layers

Oxford X-calibur and Bruker Advance

Mainly low temp. measurements (N2)

Dielectric spectroscopy

Novocontrol analyser

Freq. and temp. meas., thin layers or pressed samples

Thin film sputtering / deposition by plasma process

Quorum techno QT150 TES

Preparation of samples for electrical measurements


JEOL 5600 LV

0-30 V / LV and secondary vacuum  /  W wire


>20 students guidance over the last 10 years (from Technological DUT to M2 degree)

Responsible of the chemistry lab and of a large set of equipments (FT-IR, Mass spectrometry, HPLC…)

SCIENTIFIC PUBLICATIONS (27 peer-reviewed articles)

Spin Crossover

1-Spin-Crossover Iron(II) Coordination Polymer with Zigzag Chain Structure : G. S. Matouzenko, G. Molnar, N. Bréfuel, M. Perrin, et al., Chem. Mater. 2003, 15, 2, 550–556

2-An Unprecedented Trinuclear Structure Involving Two High-Spin and One Spin-Crossover Iron(II) centers : G. Psomas, N. Bréfuel, et al., Inorg. Chem. 2004, 43, 15, 4590–4594

3- An Abrupt Spin Crossover FeII Complex Based on Homochiral Chain : N. Bréfuel, S. Shova et al., Chem. Lett. 2005, 34, 1092-1093

4- Infinite Chain Structure and Steep Spin Crossover of a FeIII Complex with a N3O2 Pentadentate Schiff-Base Ligand and 4-Aminopyridine : K. Tanimura, R. Kitashima, N. Bréfuel et al., Bull. Chem. Soc. Japan 2005, 78, 1279-1292

5-High-spin to low-spin relaxation kinetics in the [Fe(TRIM)2]Cl2 complex : S. Bonhommeau, N. Bréfuel et al. Phys. Chem. Chem. Phys., 2005, 7, 2909-2914

6-A 2D Layered Spin Crossover Complex Constructed by NH···Cl- Hydrogen Bonds:  [FeIIH3LMe]Cl·I3 (H3LMe = Tris[2-(((2-methylimidazoyl-4-yl)methylidene)amino)ethyl]amine : M. Yamada, E. Fukumoto, M. Ooidemizu, N. Bréfuel, N. Matsumoto, et al.,  Inorg. Chem. 2005, 44, 20, 6967–6974

7-Structural−Electronic Correlation in the First-Order Phase Transition of [FeH2L2-Me](ClO4)2 (H2L2-Me = Bis[((2-methylimidazol-4-yl)methylidene)-3- aminopropyl]ethylenediamine) : N. Bréfuel, S. Imatomi, H. Torigoe, et al.,  Inorg. Chem. 2006, 45, 20, 8126–8135

8-Fe-II bi-stable materials based on dissymmetrical ligands: N-4 Schiff bases including 2-pyridyl and 5-methylimidazol-4-yl rings yield various Fe-II spin-crossover phenomena around 300 K : N. Bréfuel, S. Shova, J. Lipkowski et al. ; CHEMISTRY OF MATERIALS 2006 18, ‏ 5467-5479

9-A Range of Spin-Crossover Temperature T1/2>300 K Results from Out-of-Sphere Anion Exchange in a Series of Ferrous Materials Based on the 4-(4-Imidazolylmethyl)-2-(2-imidazolylmethyl)imidazole (trim) Ligand, [Fe(trim)2]X2 (X=F, Cl, Br, I): Comparison of Experimental Results with Those Derived from Density Functional Theory Calculations : G. Lemercier, N. Bréfuel et al., Chem. Eur. J. 2006, 12, 7421-7432

10-FeII Bistable Materials with Dissymmetrical Ligands: Synthesis, Crystal Structure, Magnetic and Mössbauer Properties of FeII Complexes Based on N4 Schiff Bases Possessing 2-Pyridyl and 1-R-Imidazol-2-yl Rings, N. Bréfuel, S. Shova, J.-P. Tuchagues, Eur. JIC 2007, 27, 4326-4334

11-FeII Spin crossover materials based on dissymmetrical N4 Schiff bases including 2-pyridyl and 2R-imidazol-4-yl rings: Synthesis, crystal structure and magnetic and Mössbauer properties : N. Bréfuel, I. Vang, et al. Polyhedron 2007, 26, 1745-1757

12-« An unprecedented co-crystal including a cis-high-spin and a trans-low-spin Fe-II complex molecule » : N. Bréfuel, C. Duhayon et al. ; CHEMICAL COMMUNICATIONS 2007, 48, ‏ 5223-5225

13- Concerted Spin Crossover and Symmetry Breaking Yield Three Thermally and One Light-Induced Crystallographic Phases of a Molecular Material : N. Bréfuel, H. Watanabe, Hiroshi et al. : Angew. Chem. Int. Ed.  2009 48 (49), 9304-9307

14-Nanoscale Self-Hosting of Molecular Spin-States in the Intermediate Phase of a Spin-Crossover Material : N. Bréfuel, E. Collet, et al. Chem Eur J 2010, 16, 14060-14068

15-Dynamical separation of spin and lattice degrees of freedom in the relaxation process from the photo-induced state : H. Watanabe, N. Bréfuel et al., Europhys. Lett. 2011 96 17004

16-Aperiodic Spin State Ordering of Bistable Molecules and Its Photoinduced Erasing: E. Collet, H. Watanabe, N. Bréfuel, et al. ; PHYSICAL REVIEW LETTERS 2012, 109  (25), 014419

17-Competing Symmetry Breaking and Spin Crossover in [FeH2L2–Me](ClO4)2 : H. Watanabe, N. Bréfuel, E. Collet et al. ; Eur JIC, 2013, 5, 710-715

18-Out-of-equilibrium dynamics of photoexcited spin-state concentration waves : A.Marino, M. Buron-Le Cointe, M. Lorenc, L. Toupet, R. Henning , A. D. DiChiara, K. Moffat, N. Bréfuel and E. Collet, Faraday Discuss., 2015, 177, 363-379

19-High-Spin / Low-Spin States Ordering Phenomena in Stepwise Spin-Crossover Materials Described by ANNNI Model : H. Watanabe, K. Tanaka, N. Bréfuel, et al. , Phys. Rev. B 2016 93, 014419

Molecular magnet and molecular chains

20-Bimetallic cyanido-bridged magnetic materials derived from manganese(III) Schiff-base complexes and pentacyanidonitrosylferrate(II) precursor : R. Ababei, Y.-G. Li, O. Roubeau, M. Kalisz, N. Bréfuel et al. New J. Chem., 2009, 33, 1237-1248

21-Enhanced Ion Anisotropy by Nonconventional Coordination Geometry: Single-Chain Magnet Behavior for a [{FeIIL}2{NbIV(CN)8}] Helical Chain Compound Designed with Heptacoordinate FeII : T. Venkatakrishnan, S. Sahoo, N. Bréfuel, et al. . Am. Chem. Soc. 2010, 132, 17, 6047–6056

22-Face-Sharing Heterotrinuclear MII−LnIII−MII (M = Mn, Fe, Co, Zn; Ln = La, Gd, Tb, Dy) Complexes: Synthesis, Structures, and Magnetic Properties :  T. Yamaguchi, J.-P. Costes, Y. Kishima, M. Kojima, Y.i Sunatsuki, N. Bréfuel et al., Inorg. Chem. 2010, 49, 20, 9125–9135

23- Seeking Hidden Magnetic Phenomena by Theoretical Means in a Thiooxoverdazyl Adduct : M. Vérot, N. Bréfuel, et al.,  Chem. Asian J. 2012, 7, 380-386

24-Rational Design of a Photomagnetic Chain: Bridging Single-Molecule Magnets with a Spin-Crossover Complex : R. Ababei, C. Pichon, N.Bréfuel; et al. ; JACS 2013, 135, ‏ 14840-14853

Organometallic chemistry

25-A New Way to Scorpionate Niobium Complexes:  Terminal Alkyne, Imido, and Oxo Complexes and the Rearrangement of α-Agostic Ethyl Complexes :  P. Oulié,, N. Bréfuel et al.,  Organometallics 2005, 24, 17, 4306–4314

Dielectric materials

26-Significance of considering pellet molding pressure and dielectric experimental conditions in the [dielectric constant—temperature] response of switchable dielectric molecular materials: illustration on dabcoHBF4 polycrystals : N. Bréfuel, L. Grilli et al. : J. Mat. Science 2021, 56, 18582–18591

27-Structural, thermal and dielectric properties of glycerolized hydrogen-bonded polyvinyl alcohol films : M. Gassab, N. Bréfuel et al. Pol. Adv. Tech. 2023, 34, 948-959

28- Low-frequency dielectric analysis of promising lead-free dabcoH+A- ferroelectric materials for energy applications : G. Morvézen, N. Bréfuel, D. Bourgault, H. Guillou, A. Sylvestre, IEEE ICD 2024

Related Posts