Donor–Acceptor Type Thioxanthones: Synthesis, Optical Properties, and Two-Photon Induced Polymerization

Abstract

A set of thioxanthone derivatives bearing strongly electrondonating dialkylamino groups have been synthesized efficiently via the Buchwald−Hartwig, Sonogashira, and Heck reactions. Compounds possessing both one and two donors have been prepared. Their optical properties proved to be intriguing. The presence of the amino group alone increased the fluorescence quantum yield 100 times. Dyes possessing arylethylene and arylethynyl linkages absorbed UV radiation and violet light while emitting (weakly) red light, as a consequence of different geometries at ground and excited states. Our design led to an increase in two-photon absorption cross sections at the wavelength of interest (800 nm) to the highest values ever recorded for thioxanthones, while maintaining excellent solubility due to the fact that all new photoinitiators are highly viscous oils at room temperature. Some of the prepared D−π−A−π−D systems also proved to be initiators in two-photon polymerization.

Tailored thioxanthone‐based photoinitiators for two‐photon‐controllable polymerization and nanolithographic printing

“…Due to the well‐understood excited state dynamics of ITX, it is useful as a starting material for the development of high‐performance polymerization photoinitiators. As such, the design of our photoinitiators is based on a previous work of the Gryko group . Moreover, in order to guide the synthetic design, computational calculations were utilized to predict the absorption spectra of a set of potential photoinitiator molecules, and the experimentally synthesized materials were those that showed the most promise from these simulations.…”

3D printing hybrid organometallic polymer‐based biomaterials via laser two‐photon polymerization

“…In most cases, the hybrid materials are rendered photosensitive by adding photoinitiators with high two‐photon absorption cross‐sections, either commercially available ones (e.g. Irgacure 2959, Irgacure 369 and Michler's ketone) or custom‐synthesized ones . Hybrid organic–inorganic materials such as those based on organometallic polymers are highly promising due to their versatility of applications and properties.…”

“…Irgacure 2959, Irgacure 369 and Michler's ketone) or custom-synthesized ones. [27][28][29][30][31] Hybrid organic-inorganic materials such as those based on organometallic polymers are highly promising due to their versatility of applications and properties. To date, organometallic materials incorporating Ge, 32 Ti, 33 V 34 and Zr 35 have been produced by LTPP.…”

3D‐Laser‐Mikro‐Nanodruck: Herausforderungen für die Chemie

“…[110] Zusammenhänge zwischen Struktur und Eigenschaften konnten fürz entrosymmetische D-p-D-oder A-p-A-Motive und, zu einem bestimmten Maß, auch fürunsymmetrische Ap-D-Motive abgeleitet werden. [111][112][113] Während man auf große Zwei-Photon-Absorptionsquerschnitte hinarbeitet, dürfen natürlich andere Eigenschaften, wie gute Lçs-Angewandte Chemie Aufsätze lichkeit, Stabilitätu nd Effizienz der Initiation, nicht vergessen werden. Diese Initiatoren funktionieren gut unter den Bedingungen der 3D-Laserlithographie,w as durch zunehmende Komplexitäti m Molekülbau und der Synthese erkauft wird.…”

“…Diese Initiatoren funktionieren gut unter den Bedingungen der 3D-Laserlithographie,w as durch zunehmende Komplexitäti m Molekülbau und der Synthese erkauft wird. [111][112][113] Während man auf große Zwei-Photon-Absorptionsquerschnitte hinarbeitet, dürfen natürlich andere Eigenschaften, wie gute Lçs- [114] Fürdas DLWkçnnte die hohe Empfindlichkeit chemisch verstärkter Photolacke große Steigerungen der Schreibgeschwindigkeiten ermçglichen, ohne umständliche Anstrengungen, den Zwei-Photonen-Absorptionsquerschnitt zu vergrçßern. Bis jetzt wurden solche Photolacke allerdings wenig verwendet;e ine nennenswerte Ausnahme bilden einige kommerzieller Photolacke wie SU-8 (Microchem), ein Epoxid-basierter Negativphotolack, der fürd ie Fabrikation von mikroelektromechanischen Systemen weit verbreitet ist.…”