Synthesis and Photochemical Investigation of Tetraacylgermanes

Abstract

Tetraacylgermanes are auspicious candidates for additive manufacturing (such as lithography based ceramic manufacturing), as they are known to show high reactivity towards (meth)acrylates and absorption at wavelengths above 460 nm. We synthesized two novel tetraacylgermanes and investigated the reactivity of these compounds with methoxy groups in the ortho position of the aromatic moiety by comparing them both to reference substances lacking this substitution pattern and to the commercial benchmark Ivocerin®. In order to rationally assess the performance of these photoinitiators, steady-state photolysis (SSP) experiments and RT-FTIR photorheology measurements were performed. Comparable strong absorption in the long wavelength region and high photoreactivity has been found for the new initiators.