Four-coordinate, low-spin (S=0) and six-coordinate, high-spin (S=1) nickel(II) complexes of tetraphenylporphyrins with beta-pyrrole electron-withdrawing substituents: porphyrin-core expansion and conformation

Research has been conducted on the porphyrin-core expansion induced by a change in the nickel(II) coordination sphere. The isolation of tetraphenylporphyrin derivatives and their study by X-ray crystallography is examined.