Deuteron Magnetic Resonance Study of Cupric Formate Tetrahydrate Cu(DCOO)2·4D2O
Deuteron Magnetic Resonance Study of Cupric Formate Tetrahydrate Cu(DCOO)2·4D2O
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四水甲酸铜Cu(DCOO)2·4D2O的氘核磁共振研究
DOI：
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发表时间：
1969
期刊：
影响因子：
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通讯作者：
Takehiko Chiba
中科院分区：
文献类型：
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作者：
G. Soda;Takehiko Chiba
用氘磁共振（DMR）研究了Cu（DCOO）2 ·4D 2 O单晶在153°K ~ 291°K温度范围内的顺电-反铁电相变（Tc =246.1±0.2°K）引起的结晶水分子结构和运动的变化.在Tc以上，水分子的DMR谱线都被7个位置上的氘核的快速运动加宽.在Tc以下，观察到20对DMR谱线，对应于4个处于稳定位置的水分子和2个甲酸根离子及其a c面对映体。通过测量这些DMR谱线的四极分裂随温度和角度的变化，得到了以下结论。相变是水分子的有序-无序类型。在反铁电相，晶胞沿c轴方向沿着发生倍化，空间群为P 2 1 / n。该结构涉及水分子的三维排序。确定了氢键网络的结构。...
Deuteron magnetic resonance (DMR) of single crystals of Cu(DCOO) 2 ·4D 2 O has been studied from 153°K to 291°K to reveal the changes in the structure and the motions of the crystalline water molecules due to the paraelectric-antiferroelectric phase transition ( T c =246.1±0.2°K). Above T c , all the DMR lines of water molecules are broadened out by fast motions of deuterons among seven sites. Below T c , 20 pairs of DMR lines are observed corresponding to four water molecules in stable position and two formate ions and their a c -plane enantiomorphs. Following conclusions are derived from measurements of temperature and angular dependences of the quadrupole splittings for these DMR lines. The phase transition is an order-disordering type of water molecules. In the antiferroelectric phase, the unit cell doubling occurs along the c -axis direction and the space group is P 2 1 / n . The structure involves a three dimensional ordering of water molecules. The structure of hydrogen-bond network is determined. ...