Tetraacylstannanes as Long‐Wavelength Visible‐Light Photoinitiators with Intriguing Low Toxicity

Abstract

The first tetraacylstannanes Sn[(CO)R]4 (R=2,4,6‐trimethylphenyl (1 a) and 2,6‐dimethylphenyl (1 b)), a class of highly efficient Sn‐based photoinitiators, were synthesized. The formation of these derivatives was confirmed by NMR spectroscopy, mass spectrometry, and X‐ray crystallography. The UV/Vis absorption spectra of 1 a, b reveal a significant redshift of the longest wavelength absorption compared to the corresponding germanium compounds. In contrast to the known toxicity of organotin derivatives, the AMES test and cytotoxicity studies reveal intriguing low toxicity. The excellent performance of 1 as photoinitiators is demonstrated by photobleaching (UV/Vis) and NMR/CIDNP investigations, as well as photo‐DSC studies.

Acylstannane: Spaltbare und hochreaktive Photoinitiatoren für radikalische Photopolymerisationen bei Wellenlängen über 500 nm mit exzellentem Photobleaching

“…[10] Danksagung Wird anken der Christian Doppler Gesellschaft und Ivoclar Vivadent fürdie großzügige finanzielle Unterstützung. Photoinitiator 1 zeigte hohe Reaktivitäti n (Meth)acrylat-Formulierungen beim Vergleich mit aktuell verwendeten PI.…”

“…Zusätzlich zeigte 1 sehr schnelles Photobleaching sowohl in Lçsung als auch innerhalb des Polymernetzwerks.I mU nterschied zu vielen bekannten Zinnorganylen zeigte 1 und auch die daraus resultierenden Photoprodukte überraschend geringe Zytotoxizität, vor allem im Vergleich mit ähnlichen Ge-Verbindungen. [10] Danksagung Wird anken der Christian Doppler Gesellschaft und Ivoclar Vivadent fürdie großzügige finanzielle Unterstützung.…”

New 1,8-Naphthalimide Derivatives as Photoinitiators for Free-Radical Polymerization Upon Visible Light

“…Therefore, the search for new photoinitiating systems with high performance under such types of irradiation is today a huge challenge. Different photoinitiating systems for LEDs were proposed recently; they are based on, for example, acylgermanes [6,7], acylstannanes [8,9], silyl glyoxylates [10], or different dye structures such as camphorquinone or anthraquinone derivatives reported in [11]. In the present paper, we propose 1,8-naphthalimide derivatives with original moieties as photoinitiators in a three-component system for the polymerization of methacrylates upon near-UV or visible LED irradiation.…”

Free Radical Photopolymerization and 3D Printing Using Newly Developed Dyes: Indane-1,3-Dione and 1H-Cyclopentanaphthalene-1,3-Dione Derivatives as Photoinitiators in Three-Component Systems

“…As abovementioned, visible light photopolymerization make use of dyes strongly absorbing in the visible range, and the color resulting from the photoinitiator in the polymer film can also be a major issue, especially when colorless coatings are desired. To date, photoinitiators capable to bleach during light irradiation are still scarce so that a great deal of efforts is currently developed by numerous research groups in order to access to these highly desired structures [29][30][31][32][33][34][35][36][37]. To this end, the development of visible light photoinitiators is also highly researched as the absorption of photoinitiators governs the choice of the irradiation sources and therefore the light penetration [38].…”