The crystal structures of chloro( meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)Cl 2, dimethoxo( meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)(OMe) 2, and dihydroxo( meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)(OH) 2, were determined. The coordination sphere of the Ge 4+ ion is a distorted octahedron in which the apical sites are occupied by two monodentate Cl − (or OMe −, OH −) groups. The geometry around the germanium centre of the Ge(tpp)Cl 2 molecule has Ge(1)Cl(1) = 2.262(1) and Ge(1)N(1) = 2.019(2) Å. In the structure of Ge(tpp)(OMe) 2 the germanium(1)-oxygen distance is 1.826(3), average Ge(1)N = 2.032(3), and O(1)C(23) = 1.331(6) Å. The structure of Ge(tpp)(OH) 2 has Ge(1)O(1) = 1.809(3) and Ge(1)N(1) = 2.027(2) Å. Two-stage hydrolysis of Ge(tpp)(OMe) 2 was studied by 1H and 13C NMR spectroscopy. The use of a limited amount of water in CDCl 3 (or CD 2Cl 2) allowed the hydrolysis intermediate, hydroxomethoxo( meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)(OMe) (OH), and hydrolysis product, dihydroxo( meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)(OH) 2, to be identified. X-ray diffraction data and solid-state 13C CP/MAS spectra of Ge(tpp)(OMe) 2 provide evidence for two monodentate methoxo groups coordinated to the germanium(IV) atom.