A supra-molecular switchable dielectric material with non-linear optical properties. Issue 11 (2nd March 2017)

• Record Type: Journal Article
• Authors: Khan, Tariq; Asghar, Muhammad Adnan; Sun, Zhihua; Zeb, Aurang; Ji, Chengmin; Luo, Junhua
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 11(2017)
• Page Start: 2865
• Page End: 2870
• Publication Date: 2017-03-02
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c6tc05574e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A supra-molecular crystal, 1-[C6 H13 NH][18-crown-6][ClO4 ] monohydrate, has been reported to show reversible dielectric anomalies and nonlinear optical properties, which suggests that it could be conceived as the potential switchable dielectric and non-linear optical material. Abstract : A novel molecular phase transition material (PTM), 1-methylpiperidinium perchlorate [18-crown-6] monohydrate (1 ), has been synthesized, which exhibits reversible switchable dielectric anomalies near room temperature. The phase transition in1 is from noncentrosymmetric to noncentrosymmetric, displaying non-linear optical (NLO) properties with a second harmonic generation response of ∼0.8 times compared to that of potassium dihydrogen phosphate. Thermal analyses of1, including differential scanning calorimetry and specific heat measurements, confirm the first-order solid-state phase transition at 260 K. The dielectric constants display temperature-dependent anomalies with the temperature approaching the transition point ( T c ), where the evident step-like anomalies demonstrate two distinct states below and above the T c value, respectively. Variable-temperature single crystal X-ray diffraction discloses that the origin of its phase transition is ascribed to the order–disorder transformation of perchlorate anion, the methyl group of cation and the torsional angular change in crown molecule; that is, all three components contribute to the emergence of this phase transition. This result suggests that1 could be conceived as a potential switchable dielectric and NLO material, which provides an effective approach to design novel NLO switch materials.