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Z. Li, M. Siklos, N.U Pucher, K. Cicha, A. Ajami, W. Husinsky, A. Rosspeintner, E. Vauthey, G. Gscheidt, J. Stampfl, R. Liska:
"Synthesis and Structure-Activity Relationship of Several Aromatic Ketone-Based Two-Photon Initiators";
Journal of Polymer Science Part A: Polymer Chemistry, 49 (2011), 3688 - 3699.

Several novel aromatic ketone-based two-photon initiators
containing triple bonds and dialkylamino groups were synthesized
and the structure-activity relationships were evaluated.
Branched alkyl chains were used at the terminal donor groups to
improve the solubility in the multifunctional monomers. Because
of the long conjugation length and good coplanarity, the evaluated
initiators showed large two-photon cross section values,
while their fluorescence lifetimes and quantum yields strongly
depend on the solvent polarity. All novel initiators exhibited high
activity in terms of two-photon-induced microfabrication. This is
especially true for fluorenone-based derivatives, which displayed
much broader processing windows than well-known highly active
initiators from the literature and commercially available initiators.
While the new photoinitiators gave high reactivity in two-photoninduced
photopolymerization at concentration as low as 0.1% wt,
these compounds are surprisingly stable under one photon condition
and nearly no photo initiation activity was found in classical
photo DSC experiment.

laser-induced polymers; NLO; photochemistry; photopolymerization; radical polymerization; two-photon absorption photoinitiator

Project Head Jürgen Stampfl:
ISOTEC III - Integrated Organic Sensor and Optoelectronic Technologies (Phase 3)