Inclusion Properties, Polymorphism and Desolvation Kinetics in a New 2-Pyridyl Iminophenol Compound with 1D Nanochannels

Abstract

The syntheses, crystal structures and solid-state inclusion properties of 3- and 2-pyridyl 3,5-diphenyl-4-hydroxy iminophenols are reported. Their solid-state organization is based on supramolecular head-to-tail chains sustained by O−H···N hydrogen bonds. It is shown that the position of the pyridinic nitrogen is crucial to determine the inclusion propensity. Although formation of nonsolvated close packed networks is observed for both compounds, the 2-pyridyl iminophenol derivative is also able to form nanochannels hosting arrays of guest molecules (toluene, acetone, chloroform). Most interestingly the toluene solvate occurs in two concomitant polymorphs, presenting different channel arrangements, whose properties are studied also by means of high-pressure X-ray diffraction. Thermal analyses are used to determine the kinetics of desolvation of all solvates, whose thermal behavior is correlated with their supramolecular structures.