Tetrathiafulvalene chemistry

Tetrathiafulvalene (TTF) is a fascinating system: it is quite rare to find a synthetic molecule endowed with such a simple architecture that is capable of concentrating intense interest from various communities of chemists! This modest-sized molecule which consists of only 14 atoms, was synthesized in the early nineteen seventies [1-3] and since then has proved to be exceptionally popular in various fields of chemistry

O-Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed-Valence Complexes

Herein we report an efficient synthesis to prepare O-doped nanographenes derived from the π-extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed-valence (MV) complexes were grown in which the organic salts organize into face-to-face π-stacks, a favorable solid-state arrangement for organic electronics. Variable-temperature electron paramagnetic resonance (EPR) measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar π-stacking architectures. Electric measurements of single crystals of the MV salts show a semiconducting behavior with a remarkably high conductivity at room temperature. These findings support the notion that π-extension of heteroatom-doped polycyclic aromatic hydrocarbons is an attractive approach to fabricate nanographenes with a broad spectrum of semiconducting properties and high charge mobilities

Redox-active tetrathiafulvalene-based architectures : from recognition to self-assembly

Date du colloque : 06/2011</p

Metal-driven Self-Assembly: the Case of Redox-Active Discrete Architectures

International audienceThe metal-driven self-assembly strategy is well-established for the construction of discrete architectures featuring a cavity. The resulting molecular rings and cages are potentially useful as hosts for complementary guests. The recent years have seen a growing interest for introduction of given functionalities, including redox properties which, among other, allow modulating the ionic charge of the cavity. Depending on which subunit is electroactive, various situations can be encountered, with a global redox activity which is ligand- or/and metal-centered and which involves -or not- electronic interactions between the constituting units. In this feature article, we propose to survey those different situations by exploring some recent examples of the growing family of redox-active self-assembled rings and cages.</p

Typing Concurrent Objects and Actors

International audienceAs informal methods do little to help their use for concurrent and distributed programming, one of the most challenging current tasks is to build tools based on formal method in order to ease the development of such applications. In this context, we propose precise type systems for concurrent object and actor oriented programming languages. This paper analyzes the type systems that we have developed for realistic languages and presents their benefits and limits. First, it introduces the kernel of an actor language used to describe and validate the proposed technic. Then, the errors we wish to detect are precisely defined. Afterwards, the first type system is defined and its properties are presented. Finally, insights are given on a second more powerful type system, which is the basis of our future work