Solvent effects on the two-photon absorption of distyrylbenzene chromophores.
A series of organic- and water-soluble distyrylbenzene-based two-photon absorption (TPA) fluorophores containing dialkylamino donor groups at the termini was designed, synthesized, and characterized. The central core was systematically substituted to modulate intramolecular charge transfer (ICT). These molecules allow an examination of solvent effects on the TPA cross section (delta) and on the TPA action cross section. In toluene, the delta values follow the order of ICT strength. The effect of solvent on delta is nonmonotonic: maximum delta was measured in an intermediate polarity solvent (THF) and was lowest in water. We failed to find a correlation between the observed solvent effect and previous theoretical predictions. Hydrogen bonding to the donor groups and aggregation of the optical units in water, which are not included in calculational analysis, may be responsible for the discrepancies between experimental results and theory.
Woo
Han Young
HY
Mitsubishi Chemical Center for Advanced Materials, Department of Materials, University of California, Santa Barbara, California 93106, USA.
Liu
Bin
B
Kohler
Bernhard
B
Korystov
Dmitry
D
Mikhailovsky
Alexander
A
Bazan
Guillermo C
GC
D000042:Absorption; D001555:Benzene Derivatives / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D017785:Photons; D012997:Solvents / Q000737:chemistry; D013343:Styrenes / Q000138:chemical synthesis / Q000737:chemistry*
D001555:Benzene Derivatives; D012997:Solvents; D013343:Styrenes; C507243:distyrylbenzene