Optical gap and fundamental gap of oligoynes and carbyne.

The optoelectronic properties of various carbon allotropes and nanomaterials have been well established, while the purely sp-hybridized carbyne remains synthetically inaccessible. Its properties have therefore frequently been extrapolated from those of defined oligomers. Most analyses have, however, focused on the main optical transitions in UV-Vis spectroscopy, neglecting the frequently observed weaker optical bands at significantly lower energies.

Facile synthesis of oligoyne amphiphiles and their rotaxanes.

Carbon-rich organic compounds containing a series of conjugated triple bonds (oligoynes) are relevant synthetic targets, but an improved access to oligoynes bearing functional groups would be desirable. Here, we report the straightforward synthesis of two series of oligoyne amphiphiles with glycoside or carboxylate polar head groups, investigate their self-assembly behavior in aqueous media, and their use as precursors for the formation of oligoyne rotaxanes with cyclodextrin hosts. To this end, we employed mono-, di-, or triacetylenic building blocks that gave access to the corresponding zinc acetylides and allowed for the efficient elongation of the oligoyne segment in few synthetic steps a Negishi coupling protocol.

Unprecedented combination of regioselective hydrodefluorination and ligand exchange reaction during the syntheses of tris-cyclometalated iridium(III) complexes.

The first reported combination of regioselective hydro-defluorination and a ligand exchange reaction during the syntheses of neutral iridium(III) complexes is presented. Surprisingly, loss of one fluorine atom per ligand combined with a complete ligand exchange reaction on the transition metal were jointly observed during a bridge-splitting and substitution reaction of two different dimeric iridium(III) precursor complexes with two different ancillary ligands. The regioselectivity of defluorination was evidenced in both cases.

Immobilization of styrene-substituted 1,3,4-oxadiazoles into thermoreversible luminescent organogels and their unexpected photocatalyzed rearrangement.

A series of styrene-substituted 1,3,4-oxadiazoles has been designed and investigated as new low-molecular-weight organogelators. The photophysical properties of the resulting thermoreversible organogels have been characterized by UV/Vis absorption and luminescence spectroscopies. Surprisingly, the gelation ability of the oxadiazoles depended on the presence of the styrene moiety as gelation of the investigated oxadiazoles did not take place in its absence.

Photopolymerized lipids self-assembly for the solubilization of carbon nanotubes.

Because they have a great propensity to aggregation in water, solubilization of carbon nanotubes (CNTs) in aqueous media remains an important challenge. Our laboratory has reported the self-organization of synthetic lipids into hemi-micellar structures at the carbon nanotubes surface. Subsequent stabilization of these carbon nanotube/lipid assembly (CNT/LA) constructs is achieved through photopolymerization of the diyne motif of the pentacosa-10,12-diynoic lipids.