Open AccessDeveloping Structural First Principles for Alkylated Triphenylphosphonium-Based Ionic Liquids
Author(s) -
Brianna O’Rourke,
Clare Lauderback,
Lara I. Teodoro,
Morgan Grimm,
Matthias Zeller,
Arsalan Mirjafari,
Gary L. Guillet,
Patrick C. Hillesheim
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c05241
Subject(s) - ionic liquid , thermal stability , intermolecular force , alkyl , ionic bonding , chemical physics , thermal decomposition , chemistry , melting point , phase (matter) , crystal structure , crystallography , materials science , computational chemistry , organic chemistry , ion , molecule , catalysis
While ionic liquids have proved to be versatile materials for a wide spectrum of applications, e.g., energy, materials, and medicine, several challenges remain concerning the rational design of novel materials. In light of this, a series of four triphenylphosphonium-based ionic liquids have been synthesized for the first time. These compounds exhibit high thermal stability with decomposition temperatures up to 450 °C. Their solid-state structures are characterized by single-crystal X-ray diffraction and the intermolecular interactions rigorously analyzed via Hirshfeld surface analysis. It was found that the unique geometries of the anions used in the study form distinct interactions with the cations. The interactions in the crystalline state are correlated with the thermal properties of the four ionic liquids to rationalize the melting points and phase transitions for each compound. The observed arrangements of the alkyl chains on the cations are investigated computationally to gain an understanding of how rotational freedom may impact the thermal properties of the compounds. By intention, each IL reported in this work offers a unique property profile and contributes to the ever-growing ionic liquid catalog.