Deprotonated diindolylmethanes as dianionic analogues of scorpionate bis(pyrazolyl)borate ligands: synthesis and structural characterization of representative titanocene and zirconocene complexes

Deprotonation of di(3-methylindol-2-yl)phenylmethane (L2H2) or View the MathML source2-methoxyphenyldi(3-methylindol-2-yl)methane(L2′H2) with two equivalents of nBuLi, followed by reactions with Cp2TiCl2 or Cp2ZrCl2 yielded complexes View the MathML sourceCp2TiL2(1),Cp2TiL2′(2),Cp2ZrL2(3)andCp2ZrL2′(4). Compounds 1–4 were characterized by NMR spectroscopy, and compounds 1, 3, and 4 were further analyzed by X-ray crystallography and elemental analysis. The molecular structures of 1, 3, and 4 illustrate that chelating di(3-methylindol-2-yl)methanes have a structural relationship to coordinated bis(pyrazolyl)borates.