Lim Ae Ran, Joo Yong Lak
Analytical Laboratory of Advanced Ferroelectric Crystals, Jeonju University Jeonju 55069 South Korea
Department of Science Education, Jeonju University Jeonju 55069 South Korea.
RSC Adv. 2018 Oct 4;8(59):34110-34115. doi: 10.1039/c8ra06268d. eCollection 2018 Sep 28.
To understand the dynamics of the cation in layered perovskite-type (CHCHNH)CuCl, the temperature-dependent chemical shifts and spin-lattice relaxation times in the rotating frame have been measured using H magic angle spinning nuclear magnetic resonance (MAS NMR) and C cross-polarization (CP)/MAS NMR techniques. Each proton and carbon in the (CHCHNH) cation is distinguished in MAS NMR spectra. The Bloembergen-Purcell-Pound (BPP) curves for H in CHCH and NH, and for the C in CH and CH are revealed to have minima at low temperatures. This implies that the curves represent the CH and NH rotational motions. The amplitude of the cationic motion is enhanced at the C-end, that is, the N-end of the organic cation is fixed to the inorganic layer through N-H⋯Cl hydrogen bonds, and becomes short with larger-amplitude molecular motions.
为了理解层状钙钛矿型(CHCHNH)CuCl中阳离子的动力学，使用H魔角旋转核磁共振(MAS NMR)和C交叉极化(CP)/MAS NMR技术测量了旋转坐标系中随温度变化的化学位移和自旋晶格弛豫时间。(CHCHNH)阳离子中的每个质子和碳在MAS NMR光谱中都能区分。CHCH和NH中H以及CH和CH中C的布洛姆伯根-珀塞尔-庞德(BPP)曲线在低温下有最小值。这意味着这些曲线代表了CH和NH的旋转运动。阳离子运动的幅度在C端增强，也就是说，有机阳离子的N端通过N-H⋯Cl氢键固定在无机层上，并且随着分子运动幅度的增大而变短。
