Relaxation Processes from the Highly Excited States in the Molecular Systems Based on the Methylene Blue

Author(s) P.O. Kondratenko1, T.M. Сакун1, Yu.M. Lopatkin2

1 National Aviation University, Cosm. Komarov Av 1, 03058 Kyiv, Ukraine

2 Sumy State University, Rimskiy-Korsakov, 2, 40007 Sumy, Ukraine

Issue Volume 4, Year 2012, Number 4
Dates Received 06 September 2012; published online 29 December 2012
Citation P.O. Kondratenko, T.M. Сакун, Yu.M. Lopatkin, J. Nano- Electron. Phys. 4 No 4, 04022 (2012)
PACS Number(s) 34.70.+e, 32.80.Rm
Key words Dye methylene blue, Highly excited state, The relaxation of excitation, Photodissociation, Electron phototransfer, Leuco form of dye.
The theoretical and experimental studies of relaxation of the methylene blue molecules (MB) out of the highly excited states have allowed to show the existence of nonbinding potential surfaces, which correspond to excited σσS* and σσN* states, which leads to bond dissociation S-C and N-C, localized in the vicinity of the symmetry axis of the MB molecule; the electron transfer from the highly excited σσS*-state of MB on the matrix causes the appearance of dication MBNH2 + typical for acidified (pH < 1) aqueous solutions of MB; two-quantum excitation of MB by light with hν < E(σσS*) leads to phototransfer electron and hydrogen atom from matrix onto MB and the formation of the leuco form of dye MBNH.