Thermodynamic phase transition triggered by distinct distortion and ordering of dipropylammonium picrate

Yuelan Zhou; Tianliang Chen; Zhihua Sun; Shuquan Zhang; Chengmin Ji; Cheng Song; Junhua Luo

doi:10.1002/asia.201402997

Thermodynamic phase transition triggered by distinct distortion and ordering of dipropylammonium picrate

Chem Asian J. 2015 Jan;10(1):247-51. doi: 10.1002/asia.201402997. Epub 2014 Oct 22.

Authors

Yuelan Zhou¹, Tianliang Chen, Zhihua Sun, Shuquan Zhang, Chengmin Ji, Cheng Song, Junhua Luo

Affiliation

¹ Key Laboratory of Optoelectronic Materials Chemistry and Physics, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022 (China).

PMID: 25339132
DOI: 10.1002/asia.201402997

Abstract

Dipropylammonium picrate (compound 1) undergoes a first-order phase transition at 185.0 K. Differential scanning calorimetry (DSC) measurements show reversible anomaly peaks with a thermal hysteresis of 10.2 K. Dielectric responses with distinct anisotropy and striking anomaly further confirm the phase transition. Detailed structural analyses demonstrate that the phase transition in 1 is dominated by order-disorder transformations of the dipropylammonium (DPA) cations and the picrate anions. Moreover, the unique distortions of the terminal propyl moieties in the flexible chain-like DPA cation also play an important role in this structural phase transition. All these results indicate that 1 is a potential phase-transition material.

Keywords: dielectric anomalies and anisotropy; distortion; order-disorder; phase transitions; picric acid.