Structural Analysis of a Banana-Liquid Crystal in the B4 Phase by Solid-State NMR

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• 作者：Kazuhiko Yamada ; Sungmin Kang ; Koji Takimoto ; Masaya Hattori ; Kei Shirata ; Susumu Kawauchi ; Kenzo Deguchi ; Tadashi Shimizu ; Junji Watanabe
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：June 6, 2013
• 年：2013
• 卷：117
• 期：22
• 页码：6830-6838
• 全文大小：413K
• 年卷期：v.117,no.22(June 6, 2013)
• ISSN：1520-5207

文摘

In this paper, we present a structural investigation of 1,3-phenylene bis[4-((4-10-decyloxyphenyl)iminomethyl)-benzoate], known as a banana-liquid crystal, in the B4 phase, which was performed by solid-state nuclear magnetic resonance (NMR) methodology combined with quantum chemical calculations. The present solid-state NMR measurements including ¹³C CPMAS, 2D TOSS-deTOSS, dipole-dephase, 1D and 2D EXSY, and MAS-j-HMQC provided accurate spectral assignments and unambiguous NMR parameters such as ¹³C chemical shift tensors, which were used for construction of the three-dimensional structure with the aid of density functional theory calculations. In the obtained molecular structure, two arms of the bent-core molecule are asymmetrically expanded such that the direction of the dipole moment is off alignment with respect to the middle line of the center benzene ring. It is this antisymmetric structure that is the origin of the twisted helical system in the B4 phase.