“…At first, people mainly modified the porphyrin ring by changing the metal atom in the center of the ring, adding different donor and acceptor substituents into the ring, [4][5][6] ligating different atoms or functional groups at the porphyrin meso site, [7][8][9] or designing the oligomers or aggregates of porphyrins, [10][11][12] to tune/enhance the NLO properties of porphyrins. Inspired by the development of organic-inorganic hybrids, researchers gradually combined graphene, [13][14][15] ferrocene, [16][17][18] C 60 [19][20][21] and other inorganic materials with porphyrins to form a series of complexes, which are used to improve the NLO performance of the porphyrins. Polyoxometalates (POMs) are a class of compounds that can reversibly accept or lose electrons without changing their structures, 22 and form a class of donor-acceptor hybrids with porphyrins containing a large π-bond, thus as expected improving the NLO performance of porphyrin materials.…”