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 supramolecular comple

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• 作者：Luigi Alvarado ; Greg Brewer ; Everett E. Carpenter ; Carol Viragh ; Peter Y. Zavalij
• 关键词：X-ray crystal structures ; Supramolecular complexes ; Iron ; Cobalt ; Imidazole
• 刊名：Inorganica Chimica Acta
• 出版年：2010
• 出版时间：1 March 2010
• 年：2010
• 卷：363
• 期：4
• 页码：817-822
• 全文大小：450 K

文摘

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)₂·H₂O and [FeHL]ClO₄·CH₃CN, respectively. Mössbauer spectroscopy and variable temperature magnetic susceptibility indicate that [FeHL]ClO₄·CH₃CN 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–H···imidazolate 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.