Luigi Alvarado - Use of acid-base and redox chemistry to synthesize cobalt(III) and iron(III) complexes of a partially deprotonated triprotic imidazole-containing Schiff base ligand: Hydrogen bound 1D linear homochiral and zig-zag heterochiral supramol...

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      Publication Details (including relevant citation   information):

      Alvarado, L.; Brewer, G.; Carpenter, E.E.; Viragh, C.; Zavalij,   P.Y. Inorganic Chimica Acta 363 (2010) 817-822

      Abstract:

      Aerial reaction of cobalt(II) perchlorate with H3(1) [H3(1) is   the tripodal ligand derived from the condensation of   tris(2-aminoethyl)amine with three equivalents of   imidazole-2-carboxaldehyde] in methanol and [FeH3(1)(ClO4)2] with   Fe(1) in acetonitrile results in the formation of   [CoH2L](ClO4)2H2O and [FeHL]ClO4CH3CN, respectively. Mössbauer   spectroscopy and variable temperature magnetic susceptibility   indicate that [FeHL]ClO4CH3CN is a low spin iron(III) species.   Both complexes were characterized by EA, IR, and single crystal   structure determinations. Both complexes crystallize in the   centrosymmetric monoclinic space group, P21/c, so both   enantiomers of the chiral complex are present. The supramolecular   features of these complexes, caused by the partial deprotonation   of the ligand and the resultant formation of   imidazole–Himidazolate hydrogen bonds, are different. [FeHL]+   forms hydrogen bonds with molecules from adjacent cells of like   chirality. This results in a linear homochiral array of iron   complexes. In contrast, [CoH2L]2+ forms hydrogen bonds with a   molecule from the same cell and one from another cell resulting   in an 1D alternating heterochiral zig-zag chain.

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