Supramolecular Redox Transduction: Macrocyclic Receptors for Organic Guests

The growth of supramolecular chemistry over the last decades has been materialized by the production of an extraordinary wide variety of macrocyclic receptors designed for binding ionic or neutral guests. In this chapter, the specific case of macrocyclic redox-responsive reporters for organic molecules, be they charged or neutral, is covered through illustrative examples of the recent literature. The recognition of small organic molecules, possibly chiral, and of macromolecules of biological interest is considered, with a special emphasis on selected applications. The chapter also addresses the recognition of redox-active organic guests by macrocyclic receptors through various examples. It presents several illustrative examples of redox-active self-assembled macrocycles. The design of the redox-receptor itself remains of critical importance, in particular in connection with the structural characteristics of the targeted guests

Functional Low Molecular Weight Gelators: Towards Fully Organic Conductive and Photoactive Nanomaterials

International audienc

Functional Low Molecular Weight Gelators and their Spontaneous Second Harmonic Generation

Organogels have recently focused much attention given their strong potential in a wide range of scientific areas, such as pharmaceutics or nanotechnologies.1 Regarding the latter, this interest mainly stems from the highly-organised structures generated in the xerogel state, i.e. after evaporation of the solvent. Most often, a network of intertwined nanofibres with high aspect ratio is obtained, which opens avenues for their implementation in future emerging technologies, notably in the fields of electronics and optics.2 In this context, our most recent efforts towards the elaboration of gels endowed with non-linear optical properties will be presented, from the design of the Donor-Acceptor (D-A) gelators to second harmonic generation (SHG) studies.3 The advantages of the gel state, i.e. a supramolecular polymer, will be highlighted in comparison with the covalent polymers usually involved in the preparation of such materials

Synthesis of TTF-Calixarene and TTF-Biphenyle assemblies

Date du colloque&nbsp;: 06/2008</p

Varied nanostructures from a single multifunctional molecular material

The control of the morphology of nanostructures formed from a single component molecular material incorporating electron accepting and donating moieties is shown, from both solution and gel states. The compound comprises one tetrathiafulvalene (TTF) and two pyrene units which act as the [small pi]-electron rich and deficient units, respectively, and which are united by amide-containing linkers whose additional role is to aide aggregation by hydrogen bonding. This role was demonstrated by IR and NMR spectroscopy. The gels were deposited onto surfaces and the solvent allowed to evaporate, leaving films formed by meshes of fibres with different morphologies in accord with the different solvents used to form the materials. Doping of these xerogels with iodine vapour afforded conducting films whose characteristics were probed with current sensing atomic force microscopy (CS-AFM), providing current maps and I-V curves which show how dramatically the processing solvent can influence the electronic properties of these xerogel-derived materials

Study of Interaction Modes in Pyrene-Based Fluorescent Organogels

International audienc