Deschenaux, Robert

2007, Gottis, Sébastien, Kopp, Cyril, Allard, Emmanuel, Deschenaux, Robert

A liquid-crystalline mixed [5 : 1]hexa-adduct of [60]fullerene was synthesized by addition of two different malonate derivatives onto C60. The hexa-adduct derivative 2 was prepared by a stepwise synthetic procedure (fullerene -> mono-adduct of C₆₀ -> hexa-adduct of C₆₀). Cyanobiphenyl and octyloxybiphenyl derivatives were selected as mesogens. The malonate derivatives showed either a monotropic nematic phase or a monotropic smectic A phase, and the hexa-adduct derivative gave rise to an enantiotropic smectic A phase.

2001, Even, Michaël, Heinrich, Benoît, Guillon, Daniel, Guldi, Dirk M., Prato, Maurizio, Deschenaux, Robert

Grafting of a ferrocene-containing liquid-crystalline malonate derivative to C₆₀ led to the mixed fullerene-ferrocene material 1 which gave rise to a smectic A phase. Cholesterol was used as liquid-crystalline promoter. X-ray diffraction experiments and volumetric measurements indicated that 1 is organized in double layered structures. The corresponding supramolecular organization within the mesomorphic lamellar phase is characterized by a microsegregation of the different units (ferrocene, fullerene, and cholesterol) in distinct sublayers. In such a smectic A phase, C₆₀ imposes the arrangement of the other molecular moieties. Photophysical studies revealed that electron transfer occurs from the donor ferrocene to the electron accepting fullerene. The formation of a long-lived radical pair, with lifetimes of the order of several hundred nanoseconds, was confirmed by time-resolved spectrometry, especially in the near infrared region, in which the radical anion of the fullerene moiety displays its characteristic fingerprint absorption.

, Nguyen, Thanh Tung, Nguyen, Thi Le Anh, Deschenaux, Robert

Liquid-crystalline gold nanoparticles were prepared by grafting mesomorphic α,β- unsaturated carbonyl olefins onto the organic shell of gold nanoparticles containing terminal olefin ligands by applying the olefin cross-metathesis. The latter reaction was performed under standard conditions using second-generation Grubbs catalyst. The title materials were found to be stable up to 200 °C and gave rise to the formation of smectic A phases in agreement with the structure and nature of the liquid-crystalline promoters. The olefin cross-metathesis proved to be a reaction of choice for the design of liquid-crystalline nanoparticles.