Phosphinine-based ligands: Recent developments in coordination chemistry and applications

[Display omitted] •Phosphinines with different coordination modes.•Phosphinines in metal–ligand cooperativity.•Phosphinines in the activation of small molecules.•Phosphinines in catalysis.•Phosphinines in material science.•Phosphinines in light-induced transformations. This review covers the progress that has been made during the last 10 years in the coordination chemistry of 1-phosphinines, 1,4-diphosphinines and 1,3,5-triphosphinines and related ligands. There is particular emphasis on the reactivity and application of phosphinine-containing transition metal complexes in relation to the electronic, structural and coordination properties of the corresponding phosphorus heterocycle.