Crystal structures of chloro(meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)Cl2, and dihydroxo(meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)(OH)2, and two-stage hydrolysis of its homologue dimethoxo(meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp) (OMe)2

Article abstract of DOI:10.1016/S0277-5387(97)00011-9

The crystal structures of chloro(meso-tetraphenylporphyrinato)germanium(IV), Ge(tpp)Cl₂, 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 Ge⁴⁺ 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)Cl₂ molecule has Ge(1) - Cl(1) = 2.262(1) and Ge(1) - N(1) = 2.019(2) A. 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) A. The structure of Ge(tpp)(OH)₂ has Ge(1) - O(1) = 1.809(3) and Ge(1) - N(1) = 2.027(2) A. 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 CDCl₃ (or CD₂Cl₂) 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.