Self-assembly of a cobalt octacyanotungstate network into a giant chiral helix

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• 作者：Takuya Shiga ; Tamaki Tetsuka ; Fumichika Iijima ; Graham N. Newton ; Hiroki Oshio
• 关键词：Supermolecule ; Helix ; Metal complex ; Cyanide bridges
• 刊名：Polyhedron
• 出版年：28 January, 2014
• 年：2014
• 卷：68
• 期：Complete
• 页码：157-163
• 全文大小：3888 K

文摘

Cyanide-bridged cobalt-tungstate one-dimensional networks, {[Co₁₇W₉(CN)₇₂(L^{R or S})₂₆(MeOH)₄]路16MeOH路64H₂O}_n (1^R or 1^S : L^{R or S} = N-(2-pyridylmethylene)-(R or S)-1-phenylethylamine), were synthesized. Single-crystal X-ray crystallography reveals that 1^R has a cyanide-bridged chiral helical one-dimensional structure, in which cyanide-bridged {Co₁₅W₈} units are linked by Co-W-Co trinuclear units. The {Co₁₅W₈} unit consists of four trigonal bipyramidal {Co₃W₂} moieties. The helical chain structure has 3₁ screw symmetry and exists as a chiral one-dimensional network. The pitch of the helix is 38 脜, exceeding that of double-stranded B-DNA (鈭?4 脜). In the Co₁₇W₉ chain, fifteen of the Co(II) ions are paramagnetic, while the remaining two Co(III) ions and all nine W(IV) ions are diamagnetic. Overall, the chains show paramagnetic behavior in the range of 1.8-300 K.