With regards to the environmental and safety concerns raised nowadays by the polymer industry, polymerization processes requiring light as the activation source are currently knowing a revival of interest after decades of disinterest. Recent progresses in photopolymerization are notably sustained by the development of new polymerization application namely 3D and 4D printing enabling an unprecedented access to structures of incredible complexity. Parallel to the manufacturing process, the polymer material itself and its composition are also facing numerous questions concerning their environmental and human health impacts. Beyond the monomers, the different additives introduced in the resin can also be potentially toxic so that a great deal of efforts is currently done to develop new photoinitiators with a toxicity assessed as being insignificant. In this field, iron-based metal complexes are candidates of choice due to the clinical demonstration of their very low toxicities. Among iron complexes, ferrocene is among the most widely studied iron-based metallocene. Due to its unique and reversible electrochemical properties as well as their absorption centred in the visible range, numerous photoinitiators have been developed with ferrocene or its oxidized form i.e. ferrocenium. Parallel to this, the remarkable electrochemical properties of ferrocenium made it an excellent candidate for its incorporation in photoinitiating systems. However, interest for iron-based photoinitiators was not limited to ferrocene and ferrocenium, and Schiff base complexes were also successfully used as initiators of polymerization. In this review, an overview of the different iron-based photoinitiating systems reported to date is presented. More precisely, if iron-based photoinitiators are developed since 50 years, a special focus will be done on photoinitiators designed for recent polymerization conditions, namely, under visible light and low light intensity.

关于当今由聚合物工业引起的环境和安全问题，经过数十年的不感兴趣，需要光作为活化源的聚合方法目前知道正在引起人们的兴趣。光聚合的最新进展尤其受到新聚合应用（即3D和4D打印）的开发的支持，这使人们能够前所未有地访问具有令人难以置信的复杂性的结构。在制造过程的同时，聚合物材料本身及其组成也面临着许多有关其对环境和人类健康的影响的问题。除单体外，引入树脂中的不同添加剂也可能具有潜在的毒性，因此目前已进行了大量工作来开发新的光引发剂，其毒性被评估为微不足道。在这一领域，由于其毒性极低的临床证明，铁基金属络合物是首选。在铁络合物中，二茂铁是研究最广泛的铁基茂金属之一。由于其独特和可逆的电化学性能，以及它们的吸收集中在可见光范围内，因此开发了许多具有二茂铁或其氧化形式即二茂铁的光引发剂。与此平行的是，二茂铁的出色的电化学性能使其成为光引发体系中掺入的极佳候选者。但是，铁基光引发剂的兴趣不仅限于二茂铁和二茂铁，而且席夫碱配合物也成功地用作聚合反应的引发剂。在这篇评论中 概述了迄今为止报道的不同的铁基光引发体系。更准确地讲，如果自50年以来开发铁基光引发剂，将特别关注为近期聚合条件（即在可见光和低光强度下）设计的光引发剂。