Photochemistry of the π‐Extended 9,10‐Bis(1,3‐dithiol‐2‐ylidene)‐ 9,10‐dihydroanthracene System: Generation and Characterisation of the Radical Cation, Dication, and Derived Products
2001; Wiley; Volume: 7; Issue: 5 Linguagem: Inglês
10.1002/1521-3765(20010302)7
ISSN1521-3765
AutoresAllison Jones, C.A. Christensen, Dmitrii F. Perepichka, Andrei S. Batsanov, Andrew Beeby, Paul J. Low, Martin R. Bryce, Anthony W. Parker,
Tópico(s)Photochemistry and Electron Transfer Studies
ResumoFlash photolysis of bis[4.5-di(methylsulfanyl) 1,3-dithiol-2-ylidene]-9,10(-dihydroanthracene (1) in chloroform leads to formation of the transient radical cation species 1.+ which has a diagnostic broad absorption band at lambdamax approximately 650 nm. This band decays to half its original intensity over a period of about 80 micros. Species 1.+ has also been characterised by resonance Raman spectroscopy. In degassed solution 1.+ disproportionates to give the dication 1(2+), whereas in aerated solutions the photodegradation product is the 10-[4,5-di(methylsulfanyl) 1,3-dithiol-2-ylidene]anthracene-9(10 H)one (2). The dication 1(2+) has been characterised by a spectroelectrochemical study [lambdamax (CH2Cl2) = 377, 392, 419, 479 nm] and by an X-ray crystal structure of the salt 1(2-) (ClO4)2, which was obtained by electrocrystallisation. The planar anthracene and 1,3-dithiolium rings in the dication form a dihedral angle of 77.2 degrees; this conformation is strikingly different from the saddle-shaped structure of neutral 1 reported previously.
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