TY - JOUR AU - Li, Zhiquan AU - Siklos, Marton AU - Pucher, Niklas AU - Cicha, Klaus AU - Ajami, Aliasghar AU - Husinsky, Wolfgang AU - Rosspeintner, Arnulf AU - Vauthey, Eric AU - Gescheidt, Georg AU - Stampfli, Jürgen AU - Liska, Robert TI - Synthesis and structure-activity relationship of several aromatic ketone-based two-photon initiators PY - 2011 JF - Journal of Polymer Science Part A: Polymer Chemistry JA - J. Polym. Sci. . A SN - 1099-0518 VL - 49 IS - 17 SP - 3688 EP - 3699 L1 - http://onlinelibrary.wiley.com/doi/10.1002/pola.24806/pdf L2 - http://onlinelibrary.wiley.com/doi/10.1002/pola.24806/full L3 - http://onlinelibrary.wiley.com/doi/10.1002/pola.24806/abstract L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref01252.png M3 - 10.1002/pola.24806 UR - http://dx.doi.org/10.1002/pola.24806 N2 - 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-photon-induced 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. ID - 1252 ER -