Conformational polymorph of o-aminoanilinium(dibenzo[18]crown-6) supramolecules in [Ni(dmit)2]- salts.
Conformational polymorph of o-aminoanilinium(dibenzo[18]crown-6) supramolecules in [Ni(dmit)2]- salts.
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DOI：
10.1002/asia.200900407
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发表时间：
2010-03
期刊：
影响因子：
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通讯作者：
T. Akutagawa;Hiroyuki Koshinaka;Qiong Ye;S. Noro;J. Kawamata;H. Yamaki;Takayoshi Nakamura
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文献类型：
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作者：
T. Akutagawa;Hiroyuki Koshinaka;Qiong Ye;S. Noro;J. Kawamata;H. Yamaki;Takayoshi Nakamura
将超分子(HOPD(+))(DB[18]冠-6)阳离子引入到[Ni(Dmit)(2)](-)盐(dmit(2-)=2-硫氧-1，3-二硫醇-4，5-二硫代)中，其中HOPD(+)和DB[18]冠-6分别是邻氨基苯胺和二苯并[18]冠-6。构象多态为四方(HOPD(+))(DB[18]冠-6)[Ni(Dmit)(2)](-)(1)和单斜晶系(HOPD(+))(DB[18]冠-6)[Ni(Dmit)(2)](-)(2)。盐1和盐2中HOPd(+)的氨基分别在V型DB[18]冠-6的底部和上部形成N-H(+)O氢键，从而产生不同的超分子构象。根据超分子阳离子的构象，盐1和盐2中的[Ni(Dmit)(2)](-)阴离子排列分别为4(1)螺旋pi堆积和二维层。盐1和盐2在室温下的磁行为服从居里-魏斯定律，[Ni(Dmit)(2)](-)阴离子上的S=1/2自旋。然而，盐1的电子共振谱的g值和线宽在28K时出现了磁异常，这是由于4(1)螺旋[Ni(Dmit)(2)](-)pi堆叠中的反铁磁有序所致。当温度高于200K时，盐2的介电响应随温度和频率变化较大，而盐1的介电响应不明显。HOPd(+)在盐2的阳离子层内的分子运动有助于介电响应，这一点得到了摆运动势能曲线的从头计算和X射线晶体结构分析中大的热参数的支持。盐1晶体中固定的(HOPD(+))(DB[18]冠-6)排列与较小的介电响应一致。由于HOPd(+)的邻氨基在超分子阳离子结构中的空间位阻，形成了具有不同介电和磁性的构象多晶型。
The supramolecular (HOPD(+))(DB[18]crown-6) cation, in which HOPD(+) and DB[18]crown-6 are o-aminoanilinium and dibenzo[18]crown-6, respectively, was introduced into [Ni(dmit)(2)](-) salts (dmit(2-) = 2-thioxo-1,3-dithiole-4,5-dithiolate). Conformational polymorphs were observed as tetragonal (HOPD(+))(DB[18]crown-6)[Ni(dmit)(2)](-) (1) and monoclinic (HOPD(+))(DB[18]crown-6)[Ni(dmit)(2)](-) (2). The ammonium group of HOPD(+) in salts 1 and 2 formed the N-H(+)O hydrogen bonds at the bottom and upper positions of V-shaped DB[18]crown-6, respectively, thereby producing a different supramolecular conformation. The [Ni(dmit)(2)](-) anion arrangements in salts 1 and 2 were 4(1)-helical pi stacking and a two-dimensional layer, respectively, depending on the conformation of the supramolecular cations. The magnetic behavior of salts 1 and 2 obeyed the Curie-Weiss law at room temperature with S = 1/2 spin on the [Ni(dmit)(2)](-) anion. However, the g value and line width in the electron resonance spectra of salt 1 showed a magnetic anomaly at 28 K, which was owing to antiferromagnetic ordering in the 4(1)-helical [Ni(dmit)(2)](-) pi stack. Large temperature- and frequency-dependent dielectric responses were observed for salt 2 at temperatures above 200 K, whereas no particular dielectric responses were observed in salt 1. The molecular motion of HOPD(+) within the cationic layer of salt 2 contributed to the dielectric response, and this was supported by ab initio calculations showing the potential-energy curve for pendulum motion and by the large thermal parameters in the X-ray crystal structure analysis. The fixed (HOPD(+))(DB[18]crown-6) arrangement in the crystal of salt 1 was consistent with the small dielectric response. The steric hindrance of the o-amino group of HOPD(+) in the supramolecular cation structure yielded the conformational polymorph with different dielectric and magnetic properties.