Study of the Influence of the Metal-ligand Complex on the Size of Aqueous Metallo-supramolecular Micelles

A library of metallo-supramolecular block copolymers has been synthesized, and the micellization behavior of those copolymers in water has been studied. A series of amphiphilic block copolymers composed of poly(styrene) and poly(ethylene oxide) joined by a bis(terpyridine)ruthenium complex were prepared. The micelles formed from these copolymers were characterized by AFM and TEM. The results evidence that the classical scaling laws relating the micelle size to the size of the hydrophobic block are not valid for metallo-supramolecular copolymers. This different behavior is due to electrostatic repulsions between the charged and bulky metal-ligand complexes present at the core-corona interface. If those repulsions are screened by increasing the ionic strength during micelle formation, the classical behavior is observe

Growth and characterization of benzylic amide [2]catenane thin films

We report here the first results on the thin-film growth of benzylic amide catenanes. The films were deposited onto gold single crystals by two different methods: by sublimation under ultra-high vacuum and by dipping of the substrate into a solution of the catenane. Sublimation yielded well-ordered films (domain diameter ~100 Å) while dipping produced disordered films. The vibrational and electronic properties of these films were investigated by high-resolution electron energy loss spectroscopy (HREELS) as a function of film thickness. The vibrational spectra indicate that the first layer of catenanes is chemisorbed

Effect of potassium intercalation on the electronic and vibrational properties of benzylic amide [2]catenane films

The appearance of gap states in benzylic amide catenane thin films following potassium intercalation was investigated by electron energy loss spectroscopy and quantum chemical calculations. Both theory and experience find an excitation energy for transitions into these new states of ~2 eV. The characteristics of these states are discussed.

IRAS investigation of a catenane adsorption on Au(111)

The adsorption of a benzylic amide [2]catenane on a Au(111) single crystal has been studied using infrared reflection absorption spectroscopy. The evolution of the infrared spectra during catenane deposition at different temperatures of the gold substrate (300 and 90 K) has been compared. Evidence of the catenane deformation upon chemisorption have been found at 300 K only. At 90 K the catenane is weakly adsorbed without any deformation.

Photoemission study of pristine and potassium intercalated benzylic amide [2]catenane films

In this paper we report a photoelectron spectroscopy (XPS and UPS) study of films of a benzylic amide [2]catenane on Au(111). We show that this molecule retains its molecular integrity during sublimation and that it chemisorbs on the metal surface. Potassium intercalation modifies the electronic structure of the films. We have observed a reduction of its amide functions and a modification of the charge density of the aromatic rings. The creation of polaron-like states in the gap of the neutral catenane and a decrease in the catenane work function of 0.8 eV have been demonstrated.