Biomedical subjects

Ulla Létinois-Halbes

Publications and source records attributed to Ulla Létinois-Halbes.

3 recordsLinked to original sources

PubMed2005

A fast-moving [2]rotaxane whose stoppers are remote from the copper complex core.

[reaction: see text] A new copper-complexed rotaxane is described. It consists of a two-coordination site ring threaded by a sterically non-hindering 2,2'-bipyridine derivative. An electrochemical signal (oxidation or reduction of the copper center, Cu(I) or Cu(II)) induces rearrangement of the system. By using long and flexible linkers between the stoppers and the central complex, ligand exchange is fast, which leads to short response times (on the millisecond time scale and even below).

Journal Article↗

PubMed2005

Ag NMR as a tool for mechanistic studies of Ag-catalyzed reactions: evidence for in situ formation of alkyn-1-yl silver from alkynes and silver salts.

[Structure: see formula]. As demonstrated by 1H, 13C, and 109Ag NMR, a pi-alkyne-Ag complex and then an alkynyl silver are in situ formed from alkyne and silver salt in conditions related to those used for Ag-catalyzed alkynylation or for Ag/Pd-catalyzed sp-sp2 cross-coupling reactions. This finding allows for a rationale of the mechanisms of these reactions.

Journal Article↗

PubMed2004

Triphenylphosphane complex formation with hexyn-1-yl silver.

Hexyn-1-yl silver shows broad signals in 1H, 13C and 109Ag NMR. In the presence of 1 equiv. of triphenylphosphane, the signals are much sharper and at low temperature 109Ag,31P and 107Ag,31P coupling can be observed. On 109Ag decoupling, the 31P spectrum still shows the 107Ag,31P coupling indicating the formation of a coordination complex.

Alkynes↗