The rich chemistry of molecules exhibiting a quinoid structure has attracted the interest of a large scientific community for decades owing to their implications in a wide range of science. More recently, these molecules appeared to be also precusors of choice for on-surface synthesis. Two different approaches and the key role of the quinoidal precursors will be described and discussed in the presentation. The first approach will be devoted to the formation on surface of micrometer-sized materials based on covalent coordination bonds (by a controlled co-deposition process). The second approach will concern the chemical modification of a material on surface.