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.