Homochiral column structure of rac- and Λ-[MIII(tn)3]P3O9 (M = Co, Cr; tn = 1,3-diaminopropane; P3O9 = cyclotriphosphate(3−)) produced by multiple hydrogen bonds
説明
The crystal structures of rac- and Λ-[MIII(tn)3]P3O9·nH2O (M = Co, Cr; tn = 1,3-diaminopropane = trimethylenediamine; P3O9 = cyclotriphosphate(3−)) were determined by single-crystal X-ray analyses. In rac-[Co(tn)3]P3O9·7.3H2O, the [Co(tn)3]3+ cations with the same absolute configuration (Δ or Λ) and the P3O93− anions are alternately arrayed and connected by multiple NH⋯O hydrogen bonds to form a homochiral columnar structure. Adjacent homochiral columns with opposite chirality are connected by intercolumn hydrogen bonds to form a racemic pair of columns. The crystal structure of rac-[Cr(tn)3]P3O9·7.5H2O is similar to that of the Co complex; however, there exist two types of racemic pairs of columns. In the crystal of Λ-[Co(tn)3]P3O9·2.5H2O, a pair of columns consisting of alternately stacked Λ-[Co(tn)3]3+ cations and P3O93− anions are linked by hydrogen bonds. Neighboring column pairs are further linked by hydrogen bonds to form a three-dimensional (3-D) sheet structure. The crystal structure of Λ-[Cr(tn)3]P3O9·2.5H2O is isomorphous with the Co complex. The circular dichroism (CD) spectra of aqueous solutions of Λ-[M(tn)3]Br3 (M = Co, Cr) change when P3O93− is added, and the changes were explained by ion pair formation through hydrogen bonds.
収録刊行物
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- New Journal of Chemistry
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New Journal of Chemistry 34 2777-, 2010-01-01
Royal Society of Chemistry (RSC)
