Design, synthesis and characterization of a phosphino-azine ligand

Azine compounds has recently gained significant attention due to the interesting properties that they display which could be relevant in fields such as Pharmacology and Material Sciences. These types of ligands recently stand out in Coordination Chemistry because of the facilities that exhibit to easy coordinate to diverse transition and post-transition metal ions. Besides to the azine skeleton (C=N-N=C), the addition of other donor atoms in the brands such as sulphur, oxygen or phosphorus in the ligand increases the coordination possibilities. In this sense, we are interested in azine ligands as precursors of metallosupramolecular architectures which could shown interesting properties.

The research herein reported is focused on the design, synthesis and characterization of a potentially dianionic and tetradentate [P₂O₂] organic phosphino-azine ligand (LP⁸). The addition of the phosphine group to the azine skeleton allows the stabilisation of soft metal ions and the assembly of novel functional structures. The azine ligand LP⁸ has been prepared by an iminic condensation reaction between two equivalents of (diphenylphosphino)benzaldehyde and one equivalent of azine monohydrate. The obtained compound was fully characterized by using several techniques both in solution and in solid state such as elemental analysis, mass spectrometry, infrared spectroscopy, ¹H NMR spectroscopy and X-ray diffraction.