OMC team - Responsive Organometallic and Boron Scafolds (ROBoS)

RoBos Group

We are a molecular chemistry group gathering seven permanent researchers with backgrounds in main group synthesis as well as in transition and rare earth metals coordination chemistry.
We share a common interest in the molecular design and synthesis of switchable molecules and materials.
Electronic, optical and magnetic properties of these original species are at the heart of our research activity.
Benefiting from an attractive working environment, we are always glad to welcome new students from all horizons and backgrounds in our well equipped open space lab.

Photoswitching of Single Molecule Magnet

Keywords : Lanthanide complexes, Single Molecule Magnet, Photochromism

With the prominent use of magnetization-based information storage technologies in our daily life, Single-Molecule-Magnets (SMM), which are able to interconvert between two states with opposite magnetization directions, receive a great deal of attention. Circuits integrating such molecular-scale components may ultimately replace the current technologies. In order to introduce a remote control of this property with light to reach advanced switching systems and devices, we target a new kind of molecular photomagnetism that rely on relies on a ligand-centered light driven process within a metal complex containing photoswitchable ligands. Such strategy is particularly relevant for the otherwise light insensitive 4f based SMM systems because their high sensitivity to minute changes in their coordination environment maximize the impact of the photo-isomerization event on the resulting magnetic behavior.

Advanced luminescence switches

Keywords: Lanthanide complexes, NIR Emission, Photochromism, Redox Switches

The switching of near infrared light is a major challenge for various applications in the fields of information transport, medical imaging, detection or authentication of documents. Our group had a pioneering role in both developing redox active ligands that allow the control of NIR emitters luminescence by a change in the redox state and more recently by using photochromic ligand specifically designed to perform luminescence switching with light, an efficient and contactless stimulus. The combination of the two strategies also provides unique switches with dual control. Our efforts are currently directed at developing these dynamic systems towards anticounterfeiting applications, including with combination of lanthanides ions emitting in the visible and the NIR range.

luminescence switches of lanthanides ions

Light responsive Organometallic Thermoelectric and Magnetoresistive systems

Keywords :  Metal-acetylides, π-conjugated systems, photochromism, optoelectronic memory devices

Organic Magnetoresistive (OMAR) and Thermoelectric (TE) materials hold great promises for the development of smart electronic devices and for environmental issues. Both phenomena stem from the peculiar behavior of charge transport from one electrode to the other when submitted to external magnetic fields (OMAR) or heat flow (TE). However, today’s higher OMAR and TE performances are not satisfying. Therefore, new molecular systems featuring improved OMAR and TE properties must be developed. In addition, controlling the transport with an external stimulus is a key step to obtain smart TE and OMAR materials, paving the way for the design of molecular memory devices and coolers. Our efforts are currently directed at designing appropriate photochromic & organometallic metal-bis acetylides systems towards TE and OMAR technologies. These unique photoswitchable systems will be implemented and evaluated in devices as self-assemblies (transistors) or in molecular junctions.

Light responsive Organometallic Thermoelectric and Magnetoresistive systems

Photoactivable Near Infra-Red & Circularly Polarized Luminescence

Keywords: Dithienylethenes, supramolecular interactions, photochromism, chirality.

This project aims to provide to the scientific community a single molecular system capable of Photo-activatable Near Infra-Red Circularly Polarized Luminescence response, in various environments (organic solvents, physiological media, surfaces, bulk). The original systems incorporating a photochromic backbone are designed to be light-activated and provide light as an output chiral signal. Conceptually, the photochromic property of the system will control the intra-molecular interaction between two chromophores leading to i) the photo-control of excimeric NIR emission derived from intra-molecular interactions, ii) the photo-control of chiroptical properties (CPL, CD) without racemization upon photochromism by involving a stable atropisomeric molecular system in its enantiopure version.

Contact : Julien Boixel

All optical functional molecular materials

Keywords : transition metal complexes, dithienylethenes, non linear optics, molecular surfaces

Today, the foreseeable skills limitations of electronic memory devices are about to be reached. The ever-increasing data storage demand has drawn the field of data storage devices and more particularly the development of new types of optical molecular material. To date, the best way to write information at the molecular level with light relies upon the fine controllability of photochromism. In this project the photochromism will regulate the nonlinear optical properties of the molecule (NLO). The combination of photochromism and nonlinear optics gives rise to all-optical molecular systems to write, store and read information with light as the only tool. Conceptually, light is used as sole and unique external vector to write, store, transport and read the information on photoresponsive organized arrays of photochromic metal complexes, grafted onto surfaces. The originality of this approach is settling on accurate combination of photochromism and nonlinear optics (NLO) and allows to get rid of the loss-of-symmetry phenomenon with time while preserving the high NLO contrasts upon photochromism. The methodology relies on the surface-grafting of a chosen azido terminated metal complex to an alkyne pre-functionalized surface by azide-alkyne click-conjugation.

Contact : Julien Boixel

B-N bonds engeneering, aminoboranes and related polymers chemistry

Keywords: boranes, aminoboranes, hydrogen storage, polymers.

B-N bond engineering in connection with aminoboranes chemistry, and more particularly with diisopropylaminoborane (DIAB), offers a rapid and efficient route to poly(aminoboranes) as a promising family of inorganic polymers. Poly(aminoboranes) are preceramic polymers. They display within their structure dihydrogen interactions between hydridic BH and protic NH bonds (BH-…+HN) prefigurating H2 molecules as an energy vector stored in chemical form. Recently, we successfully achieved the metal-free synthesis of functionalized poly(aminoboranes). This process has been patented and their development is still under way.

B-N bonds engeneering, aminoboranes and related polymers chemistry

Synthesis Methodology and Heterochemistry

Keywords: Heterochemistry (B, Si, P…), heterocycles, photochromes, polymers

Photoresponsive scaffolds including P block elements are valuable molecular targets due to the tunability of their electronic properties conferred by the presence of the heteroatom and its modifiable valence shell. Heterosubstituted dithienylethene-based photochromes are in this prospect valuable candidates requiring new and efficient methodological approaches for their construction. By combining the chemistry of strained heterocycles, P block elements and dithienylethenes, new photochromic scaffolds have been recently prepared and are currently studied.

Synthesis Methodology and Heterochemistry