TY  - JOUR
A1  - Strehmel, Veronika
A1  - Sarker, A. M.
A1  - Lahti, P. M.
A1  - Karasz, F. E.
A1  - Heydenreich, Matthias
A1  - Wetzel, Hendrik
A1  - Haebel, Sophie
A1  - Strehmel, Bernd
T1  - One- and two-photon photochemistry and photophysics of poly(arylenevinylene)s containing a biphenyl moiety
N2  - Photochemical and photophysical properties were investigated for poly(arylenevinylene)s containing a flexible biphenyl "hinge" unit by applying one-photon (OP) and two-photon (TP) excitation to explore excited-state properties. The poly(arylenevinylene)s were poly[(2,5-dihexyloxy-p-phenylenevinylene)-alt-(4,4'-dihexyloxy-3,3'-biph enylenevinylene)] (1), poly[(2,5-dihexyloxy-p-phenylenevinylene)-alt-(2,2'-dihexyloxy-3,3'-biph enylenevinylene)] (2), and poly[(2,5-dihexyloxy-p-phenylenevinylene)-alt-(2,2'-biphenylene-vinylene )] (3). Effective emission quantum yields and related photonic properties were evaluated on a realistic per-chromophore basis using effective conjugation lengths based on the Strickler-Berg relationship. intramolecular photocyclization was deduced to occur in the one case where the biphenyl molecular connectivity permitted the reaction, based on matrix- assisted loser desorption/ionization time-of-flight (MALDI-TOF), heteronuclear multiple-quantum coherence (HMQC)-NMR, and gel-permeation chromatography (GPC) results. The various photoprocesses could be induced by either OP or TP excitation, though the first excited singlet state is the photoactive state. The higher excitation energy 1 of the TP excited state favors indirect population of the S, state by electronic coupling between the TP and OP excited states [lambda(max)(TPE) (nm): 726; delta (GM)([9]): 1 = 229, 2 = 215, 3 = 109). Photochemical processes occurring from the lowest OP excited state (S-1) could therefore also be indirectly induced by TP excitation
Y1  - 2005
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/13894
SN  - 1439-4235
ER  -