Metalla-supramolecular rectangles as electron reservoirs for multielectron reduction and oxidation.
The electron-transfer capacity of molecular rectangle ions [Pt(II)(4)(PEt(3))(8)(mu-anth(2-))(2)(mu-L)(2)](4+) with anth = anthracene-1,8-diyl and L = 4,4'-bipyridine (bp) or 1,2-bis(4-pyridyl)ethene (bpe) was investigated in acetonitrile and dichloromethane using cyclic voltammetry, EPR, and UV-vis-near-IR spectroelectrochemistry. The compounds can be reversibly reduced, first in a two-electron process and then via two closely separated one-electron steps. Oxidation was also possible at rather low potentials in a reversible two-electron step, followed by an electrochemically irreversible process. The spectroscopic results indicate reduction at the neutral acceptor ligands L and oxidation at the formally dianionic anthracene "clips". In contrast, the prototypical molecular square ([Pt(triphos)(mu-bp)](4))(8+) undergoes only irreversible reduction.
Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany. kaim@iac.uni-stuttgart.de
Wolfgang
W
Kaim
Brigitte
B
Schwederski
Akbey
A
Dogan
Jan
J
Fiedler
Christopher J
CJ
Kuehl
Peter J
PJ
Stang
D000873:Anthracenes / Q000737:chemistry; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction
D000873:Anthracenes; D008024:Ligands; D009944:Organoplatinum Compounds; C034020:anthracene