Dalton communications. Functionalizable 5,5,10,10,15,15,20,20-octaethylporphyrinogen complexes of early transition metals: synthesis and crystal structure of titanium-, vanadium- and chromium-(III) derivatives and a two-electron oxidation of the porphyrinogen skeleton

Titanium-, vanadium- and chromium-(III) complexes of 5,5,10,10,15,15,20,20-octaethylporphyrinogen (L) have been synthesized and characterized by X-ray crystallography. They show bifunctional binding of LiCl. A hemiporphyrin–hemiporphyrinogen chromium(III) derivative, which forms via a two-electron oxidation of L under slightly different reaction conditions, has also been isolated and the crystal structure determined.