In this invited frontier article, recently discovered d6 and d10 complexes with long-lived metal-to-ligand charge transfer (MLCT) excited states are highlighted. Chelating diisocyanide ligands give access to emissive Mo(0) and Cr(0) complexes with d6 electron configuration exhibiting photophysical properties similar to those of Ru(ii) polypyridines or cyclometalated Ir(iii) complexes. With Ni(0), these ligands yield luminescent tetrahedral d10 complexes similar to isoelectronic Cu(i) bis(diimine) compounds.