Ni(II) tetrahydronorcorroles: antiaromatic porphyrinoids with saturated pyrrole units.

While hydrogenated porphyrins are abundant in natural and synthetic compounds, antiaromatic hydrogenated porphyrinoids have not been synthesized to date. Here, we report bacteriochlorin-like Ni-II tetra-hydronorcorrole complexes as the first examples of antiaromatic porphyrinoids that contain saturated pyrrole units.