Structure and Thermodynamic Properties of (C5H12N)CuBr3: A New Weakly Coupled Antiferromagnetic Spin-1/2 Chain Complex Lying in the 1D鈥?D Dimensional Cross-Over Regime

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• 作者：Bingying Pan ; Yang Wang ; Lijuan Zhang ; Shiyan Li
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：April 7, 2014
• 年：2014
• 卷：53
• 期：7
• 页码：3606-3610
• 全文大小：300K
• 年卷期：v.53,no.7(April 7, 2014)
• ISSN：1520-510X

文摘

Single crystals of a metal organic complex (C₅H₁₂N)CuBr₃ (C₅H₁₂N = piperidinium, pipH for short) have been synthesized, and the structure was determined by single-crystal X-ray diffraction. (pipH)CuBr₃ crystallizes in the monoclinic group C2/c. Edging-sharing CuBr₅ units link to form zigzag chains along the c axis, and the neighboring Cu(II) ions with spin-1/2 are bridged by bibromide ions. Magnetic susceptibility data down to 1.8 K can be well fitted by the Bonner鈥揊isher formula for the antiferromagnetic spin-1/2 chain, giving the intrachain magnetic coupling constant J 鈮?鈭?7 K. At zero field, (pipH)CuBr₃ shows three-dimensional (3D) order below T_N = 1.68 K. Calculated by the mean-field theory, the interchain coupling constant J鈥?= 鈭?.91 K is obtained and the ordered magnetic moment m₀ is about 0.23 渭_B. This value of m₀ makes (pipH)CuBr₃ a rare compound suitable to study the 1D鈥?D dimensional cross-over problem in magnetism, since both 3D order and one-dimensional (1D) quantum fluctuations are prominent. In addition, specific heat measurements reveal two successive magnetic transitions with lowering temperature when external field 渭₀H 鈮?3 T is applied along the a鈥?axis. The 渭₀H鈥?i>T phase diagram of (pipH)CuBr₃ is roughly constructed.