Novel Non-Cytotoxic Acylphosphinates and Acylphosphine Oxides Photoinitiators

This study focused on the design and synthesis of a series of novel acylphosphine oxide (APO) and acylphosphinate photoinitiators based either on diphenylphosphine oxide (DPO) or 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO), systematically investigating the structure-property relationships in terms of photochemical performance, polymerization efficiency and cytotoxicity. Polymerization experiments demonstrated that DPO-based photoinitiators exhibit excellent photopolymerization efficiency, while the structurally optimized DOPO-based Type I photoinitiators also exhibit good reactivity. Biocompatibility experiments indicate that acylphosphinates (e.g., the (6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)(2,4,6-trimethoxyphenyl)methanone (TMO-DOPO) derivative) exhibit no significant toxicity toward C3H10 T1/2 mouse mesenchymal stem cells, significantly outperforming the traditional 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO) photoinitiator. These results highlight the DOPO role as a functional core in Type I initiation systems, providing an effective strategy for developing novel, efficient, and low-toxicity photoinitiators.