Role of crystallization water molecules on hydrogen-bonded structures and dielectric phase transitions in amino trimethylene phosphonic acid-based crystals

Abstract

Three hydrogen-bonded organic salts (HTBA)₂(H₄ATMP)·(H₂O)₃ (1), (HTBA)₆(H₃O)(H_2.5ATMP)₂·(H₂O)₂ (2) and (HTBA)₆(H₃ATMP)₂·H₂O (3) were synthesized by combining different molar ratios of amino trimethylene phosphonic acid (H₆ATMP) and tert-butylamine (TBA). There are three-dimensional hydrogen-bonded networks in 1–3. The crystallization water molecules that are loosely trapped in the supramolecular hydrogen-bonded networks in 1 and 2 undergo order–disorder transitions whose dynamic changes are likely to be responsible for dielectric transitions and relaxations.