New Ionic Plastic Crystals of NR<sub>4</sub>BEt<sub>3</sub>Me (R = Me and Et) and NR<i><sub>x</sub></i>R′<sub>4−</sub><i><sub>x</sub></i>BEt<sub>3</sub>Me (R = Et, R′ = Me and Pr, <i>x</i> = 1–3) in a New Class of Plastic Crystals
作者:Tomoyuki Hayasaki、Satoru Hirakawa、Hisashi Honda
DOI:10.1246/bcsj.20130040
日期:2013.8.15
New ionic plastic crystals of NR4BEt3Me (R = Me and Et) and NRxR′4−xBEt3Me (R = Et, R′ = Me and Pr, x = 1–3) were formed in a new region of plastic crystal. In this area, globular cations and anions are assembled by weak interactions. On the basis of our results of 1H and 13C NMR spectra and electrical conductivity measurements, we could conclude that isotropic reorientation and self-diffusion of globular cations and anions were detected in the crystal. X-ray diffraction (XRD) lines observed in RxR′4−xBEt3Me (R = Et, R′ = Me, x = 0–4) revealed a CsCl-type cubic crystal structure. Additionally, DSC spectra revealed that this new class of plastic crystals displays low phase-transition temperatures in the plastic phase and have high melting points. The former tendency is frequently detected in molecular plastic crystals while the latter is often found in ionic plastic crystals.
新型的NR4BEt3Me (R = Me和Et)和NRxR′4−xBEt3Me (R = Et, R′ = Me和Pr, x = 1–3)离子塑料晶体在新区域的塑料晶体中形成。在这一区域,球状阳离子和阴离子通过弱相互作用组装在一起。根据我们对1H和13C NMR谱图及电导率测量的结果,可以得出结论:在晶体中检测到了球状阳离子和阴离子的各向同性重定向和自扩散。X射线衍射(XRD)线在RxR′4−xBEt3Me (R = Et, R′ = Me, x = 0–4)中揭示了一个CsCl型立方晶体结构。此外,DSC谱图显示这类新型塑料晶体在塑料相中具有较低的相变温度,并且熔点较高。前一种趋势在分子塑料晶体中经常被检测到,而后一种则通常在离子塑料晶体中发现。