Synthesis of new organometallic complexes of Fe (III), Co (III) and Ni (III) coordinated to asymmetric Schiff bases to mediate photo-OMRP

Abstract

Organometallic complexes of FeIII, CoIII and NiIII will be synthesized to mediate / control organometallic-mediated radical photopolymerization reactions - Photo-OMRP (Organometallic-Mediated Radical Polymerization). The proposal is to systematically evaluate different combinations of coordinate ancillary ligands to different transition metals and, consequently, to achieve a fine adjustment through the variation of the electronic and steric contributions in the metallic center, directing the reactivity of these organometallic complexes to act efficiently in the photo-OMRP. The ligands evaluated will be different unpublished asymmetric Schiff bases coordinated to the metal center of Fe, Co or Ni versus the polymerization of vinyl monomers via photo-OMRP. The proposal extends in three stages, which are completely interconnected in the development process. Initially, the attention will be focused on the synthesis of tetradentate asymmetric Schiff bases. The second step will be focused on the synthesis of the Fe (II), Ni (II) and Co (II) complexes coordinated with the different Schiff base ligands. The third step will be dedicated to the evaluation of the efficiency of Fe (II), Ni (II) and Co (II) complexes in the photo-OMRP reaction. The final step will be to select the Fe (II), Ni (II) and Co (II) complexes with the best performances and submit them to an addition reaction with the radical generated by the photochemical cleavage of a symmetric primer for obtain the organometallic complexes (III). It is intended, therefore, to establish fundamentals for the understanding of the performance of the mediators, as well as the formation of the reaction intermediates involved in each reaction, allowing the planning of systems that combine reactivity and selectivity for the synthesis of new materials with differentiated architecture via photo-OMRP. (AU)