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• 作者：Lili Chu^a ; Baibin Zhou^a ; ^b ; ^{zhou_bai_bin@163.com} ; Chunxiao Wang^a ; ^{wangchunxiao842@yahoo.com.cn} ; Zhifeng Zhao^a ; ^b ; Zhanhua Su^a ; Kai Yu^a
• 关键词：Polyoxometalates ; Nickle ; Sandwich-type structure ; Electrochemical behavior ; Magnetic property
• 刊名：Solid State Sciences
• 出版年：2011
• 出版时间：February 2011
• 年：2011
• 卷：13
• 期：2
• 页码：488-491
• 全文大小：733 K

文摘

A novel 6-Nickel-substituted tungstophosphate Na₂₁[Na₃(H₂O)₈{Ni₃(H₂O)(B-α-PW₉O₃₄)(B-β-PW₈O₃₁)}₂]·36H₂O(1) has been successfully synthesized in aqueous solution and structurally characterized by single-crystal X-ray diffraction, elemental analysis, TG and IR. Polyanion [Na₃(H₂O)₈{Ni₃(H₂O)(B-α-PW₉O₃₄)(B-β-PW₈O₃₁)}₂]²¹⁻ is composed of two {Ni₃(H₂O)(B-α-PW₉O₃₄)(B-β-PW₈O₃₁)}¹²⁻ subunits linked by three Na⁺ ions. And each {Ni₃(H₂O)(B-α-PW₉O₃₄)(B-β-PW₈O₃₁)}¹²⁻ subunit is composed of two nonequivalent Keggin fragments, [B-β-PW₈O₃₁]⁹⁻ and [B-α-PW₉O₃₄]⁹⁻ held together via three Ni²⁺ ions. A new 1D network architecture is built up of the adjacent sandwich polyanions [Na₃(H₂O)₈{Ni₃(H₂O)(B-α-PW₉O₃₄) (B-β-PW₈O₃₁)}₂]²¹⁻ through two Na⁺ ions. The electrochemical behavior is elucidated in the pH = 5 (0.2 M Na₂HPO₄+ NaH₂PO₄) buffer solution employing cyclic voltammetry. Two reversible redox peaks correspond to the redox of the W^VI. An investigation of the magnetic property indicates that the six nickel centers exhibit dominantly ferromagnetic exchange interaction.