Synthesis of One‐Component Type II Visible‐Light‐Absorbing Chalcones Containing Fused Aromatic Rings and Investigation of Free Radical Photopolymerization Properties

Abstract

AbstractThis paper presents four one‐component Type II visible‐light‐absorbing chalcones (CY10‐13) that containing various fused aromatic rings as its π‐conjugated moiety, that is a 2‐naphthalene moiety for CY10, 1‐naphthalene for CY11, benzofuran for CY12, and benzothiophene for CY13. The absorption region changes significantly when introducing various fused aromatic rings. However, they all exhibit good absorption properties ranging from 300 to 450 nm that can be well‐matched under ultraviolet (UV), 365 and 405 nm light irradiations. Furthermore, the structure–reactivity relationship is also studied through thermal, photochemical, electrochemical, and computation properties. Finally, all the chalcones demonstrate photoinitiating ability without additive additional hydrogen donor in their systems. Both of the CY11 and CY12 based photoinitiating formulations initiate sufficiently upon UV and light‐emitting diode (LED)@405 nm light exposures. Furthermore, triphenylamine‐substituted chalcone analogous (CY8) is added for comparison. Although CY10‐13 compounds have lower light harvesting regions than CY8, some of those new chalcones exhibit better photoreactivity. Thus, a chalcone containing fuses aromatic ring featuring straightforward synthesis as well as versatile absorption region and photoinitiating performance, has great potential in photopolymerization applications.