Équipe OMC - Groupe Phosphore et Matériaux Moléculaires
From left to right: M. Hissler, H. Isla, T. Reynaldo, J. Crassous, P.-A. Bouit, L. Favereau, T. Dombray, A. Mocanu, R. Bouvier, F. Chadoura, S. Evariste, B. Rkein, R. Szücs, M. Duffy
The research activities of the "Phosphorus and Molecular Materials" group are mainly oriented toward the synthesis of molecular, supramolecular or polymeric pi-conjugated system featuring specific physico-chemical properties (absorption, luminescence, chiroptical properties, charge transport...). The main applications of these systems are in the field of optoelectronics.
The originality of our approach consists in using the chemistry of organophosphorus/helicenes associated with organometallic/coordination chemistry to prepare unprecedented molecules. Physico-chemical and theoretical studies allow us to understand the properties and determine their field of applications.
Main research areas :
M. Hissler - P.-A. Bouit
1- Organosphosphorus pi-conjugated oligomers and polymers
We develop phospholes (1) as building block for π-system engineering. The weak aromaticity of phosphole allows the synthesis of chromophore/fluorophore with appealing properties. Tailoring the substituents at the 2 and 5 position allows HOMO-LUMO gap tuning. Phosphole-based semi-conducting polymers have also been synthesized. Di-phospholes linked through a P-P bond allows to prepare compounds with unusual σ-π conjugation and reduced HOMO-LUMO gap. Coordination chemistry at the P-atom permit to modify the optical properties and the arrangement of the compounds. Finally, these compounds were successfully introduced into colored and white OLED.
Angew. Chem. Int. Ed. 2000, 39, 1812; Chem. Commun. 2002, 1674; J. Am. Chem. Soc. 2003, 125, 9254; J. Am. Chem. Soc. 2004, 126, 6058; J. Am. Chem. Soc. 2006, 128, 983; Angew. Chem. Int. Ed. 2006, 45, 6152-6155; Adv. Mat. 2009, 20, 1; Adv. Func. Mater. 2012, 22, 567; Angew. Chem. Int. Ed. 2012, 51, 214; Org. Letters 2013, 15, 330; J. Mater. Chem. C 2016, 4, 3686; Chem. Soc. Rev. 2016,10.1039/C6CS00257A.
In this project we synthesized the first example of polycyclic aromatic hydrocarbons (PAH) featuring a P-atom. P-reactivity allows unprecedented fine tuning of HOMO-LUMO gap and coordination driven assembly in the solid state. These compounds were also inserted into white-OLEDs.
J. Am. Chem. Soc. 2012, 134, 6524-6527; Chem. Eur. J. 2015, 21, 6547; Dalton Trans. 2016, 45, 1896.
3-Electronic properties of P-heterocycles
Organophosphorus chemistry give rise to a great variety of pi-conjugated systems depending on the size of the heterocycle (4-5-6 membered ring) or the hybridation of the P atom. In the frame of different collaborations (COST Phoscinet, COST EuSips, LIA FOM ...), we explored the electronic properties of unusual pi-conjugated P-scaffolds (phosphetes, phosphinines) thus paving the way to novel functional building blocks for opto-electronic applications.
J. Crassous - L. Favereau - T. Reynaldo
1- Synthesis and coordination of phosphorated heterohelicenes; impact of the metal on the chiroptical properties
In our group, we are currently preparing azahelicenes bearing phospholes and studying the coordination of such P,N chelates to metallic ions, in order to conceive new chiral molecules with original topologies. This strategy enables to prepare a diversity of structures simply by changing the metallic ion. By this method, we have been able to prepare enantiomerically pure azahelicene-phospholes and their corresponding PdII and CuI complexes (see Figure), which displayed high molar rotations and circular dichroism values. Of particular interest the impact of the metal on the chiroptical properties was investigated by theoretical calculations.
Pr. Christian ROUSSEL, Dr. Nicolas VANTHUYNE, Faculté des Sciences de Saint Jérôme, Marseille : séparations par HPLC chirale.
Pr. Jochen AUTSCHBACH, University of Buffalo, USA, calculs théoriques des propriétés chiroptiques (CD, ORD).
2- Metallahelicenes: first organometallic helicenes
We have recently demonstrated that it was possible to use organometallic chemistry to create a helicene incorporating a metallic ion into its helical backbone. Such method allowed the preparation of the first platinahelicenes and provided these new chiral molecules with new properties such as phosphorescence at room temperature. Moreover these metallahelicenes display huge chiroptical properties (molar rotation and circular dichroism) and can be prepared in a few steps. We hope that this method will be useful to create a diversity of helicenes incorporating metallic ions.
Pr. Christian ROUSSEL, Dr. Nicolas VANTHUYNE, Faculté des Sciences de Saint Jérôme, Marseille, chiral separation by HPLC.
Pr. Jochen AUTSCHBACH, University of Buffalo, USA
Pr. J. A. Gareth WILLIAMS, University of Durham (England)
3- Chiral molecules for parity violation (PV) experiments
Since several years, Jeanne Crassous is involved in the search of parity violation (PV) or parity non conservation (PNC) effects in chiral molecules, in collaboration with physicists, theoretical chemist and spectroscopists. This project aims at measuring the tiny energy difference which exists between two enantiomers of a chiral molecule. While for a long time the molecule of choice has been the bromochlorofluoromethane (see Figure) we are now currently investigating simple chiral oxorhenium complexes.
Dr Laure GUY, ENS Lyon: Analyse de molécules chirales.
Pr. Christian ROUSSEL, Dr. Nicolas VANTHUYNE, Faculté des Sciences de Saint Jérôme, Marseille : séparation by HPLC chirale.
Pr Larry NAFIE, Pr Tess FREEDMAN, Syracuse University (USA) : mesures VCD
Dr. Christian CHARDONNET, Pr. Anne AMY-KLEIN, Dr. Christophe DAUSSY, Dr. Benoît DARQUIE, LPL Villetaneuse : mesures d’effets de violation de parité par spectroscopie IR à très haute résolution.
Dr. Trond SAUE, Université de Strasbourg: calculs relativistes d’effets de violation de parité dans les molécules.
Dr. Pierre ASSELIN, Dr. Pascale SOULARD (LASIM, Paris), Pr Thérèse HUET (PhLAM Lille) : mesures spectroscopiques.