Time resolved excitation dynamics in emeraldine base

0444776 - ÚMCH 2016 RIV NL eng J - Journal Article
Menšík, Miroslav - Rais, David - Pfleger, Jiří
Time resolved excitation dynamics in emeraldine base.
Chemical Physics. Roč. 456, 29 July (2015), s. 79-84. ISSN 0301-0104. E-ISSN 1873-4421.
[International Conference Electronic and Related Properties of Organic Solids /13./ - ERPOS 2014. Świeradów Zdrój, 06.07.2014-10.07.2014]
R&D Projects: GA MŠMT LH12186; GA MŠMT(CZ) LD14011; GA ČR GAP108/12/1143
Grant - others:European Commission(XE) COST Action MP1202 HINT
Institutional support: RVO:61389013
Keywords : polyaniline * emeraldine base * transient absorption spectroscopy
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.758, year: 2015

Using femtosecond pump–probe transient absorption spectroscopy (wavelengths 330–800 nm), we observed and explained excited state, charge transfer and polaron state dynamics in emeraldine base form of polyaniline in dimethyl sulfoxide solution. The excited state created by a pump pulse (700 nm) in the quinoid absorption Q-band loses its initial symmetry by subsequent energy transition to a charge transfer state within 50 fs. The hot charge transfer state either recombines non-radiatively into the ground state with decay time constant 0.55 ps or transfers into a relaxed state corresponding to the relaxed phenyl geometry during ca 2.1 ps. This relaxed state shows a prolonged lifetime of about 6.5 ps before its recombination to the ground state. However, a small amount of long-lived polarons with lifetime of about 2 ns in air and with lifetime longer than 6 ns in the solution bubbled with dry N2 was detected.
Permanent Link: http://hdl.handle.net/11104/0247657