Electroorganic reactions. Part 55.† Quinodimethane chemistry. Part 3. Transition metal complexes as inter- and intra-molecular redox catalysts for the electrosynthesis of poly(p-xylylene) (PPX) polymers and oligomers‡
作者:Robert G. Janssen、James H. P. Utley、Emmanuelle Carré、Evelyne Simon、Heike Schirmer
DOI:10.1039/b103274g
日期:——
The role of metal complexes as redox mediators in the electrosynthesis of poly(p-xylylenes) (PPXs) has been explored, with a view to designing metal-containing precursors that can act both as mediators and starting materials for metal-containing polymers. A number of transition metal complexes [Cr(III), Ni(II) and Co(II)] are efficient redox catalysts for production of quinodimethanes, and hence PPXs. Following encouraging results from experiments using mediators based on anthranilic acid and salicylaldehyde ligands a macrocyclic compound was designed, and successfully prepared by a convergent route that incorporated both a 1,4-bis(chloromethylarene) function as a precursor to a quinodimethane and a Ni(II) salen unit as an intramolecular redox catalyst. The macrocycle was successfully reduced cathodically to yield a PPX polymer with bound Ni(II). Evidence is presented for the operation of intramolecular redox catalysis (homomediation).
Redox Switchable Daisy Chain Rotaxanes Driven by Radical–Radical Interactions
作者:Carson J. Bruns、Marco Frasconi、Julien Iehl、Karel J. Hartlieb、Severin T. Schneebeli、Chuyang Cheng、Samuel I. Stupp、J. Fraser Stoddart
DOI:10.1021/ja500675y
日期:2014.3.26
to elucidate the electrochemicalswitching mechanism of the major cyclic daisychain products, which relies on spin-pairing interactions between V(•+) and BB(2(•+)) radical cations under reductive conditions. These daisychains are of particular interest as electrochemically addressable molecular switches because, in contrast with more conventional bistable catenanes and rotaxanes, the mechanical movement
Thermally and Electrochemically Controllable Self-Complexing Molecular Switches
作者:Yi Liu、Amar H. Flood、J. Fraser Stoddart
DOI:10.1021/ja048164t
日期:2004.8.1
Self-complexingmolecular systems are obtained when an arm component (a pi-donor) is covalently linked to a preformed macrocycle (a pi-acceptor). The resulting self-complexing compounds are not only attractive in relation to their topology, but also for their potential to undergo reversible movements, i.e., the arm can be driven out of or into the cavity of the linked macrocycle in response to temperature
Versatile Self-Complexing Compounds Based on Covalently Linked Donor-Acceptor Cyclophanes
作者:Yi Liu、Amar H. Flood、Ross M. Moskowitz、J. Fraser Stoddart
DOI:10.1002/chem.200400614
日期:2005.1
of the arm. In the case of compounds carrying a DNP ring system in their side arm, two diastereoisomeric, self-complexing conformations are observed below 272 K in hexadeuterioacetone. By contrast, control over the TTF-containing arm's movement is more or less ineffective through the thermally sensitive equilibrium although it can be realized by chemical and electrochemical ways as a result of TTF's