An in-depth study on hydrogen-bonded 3-D frameworks possessing hydrophobic layers and hydrophilic pillars

Abstract

Eight lanthanide compounds [Ln(H₂O)₉](m-BDTH)₃·9(H₂O) where Ln = Pr (1), Nd (2) and Sm (3) and [Ln(H₂O)₈](m-BDTH)₃·9(H₂O) where Ln = Eu (4), Gd (5), Tb (6), Dy (7) and Tm (8) have been synthesized at room temperature. In these compounds a new class of pillared layer framework is exemplified in which 2-D hydrophobic organic layers of π-stacked and hydrogen-bonded (m-BDTH)⁻ are separated by hydrophilic [Ln(H₂O)_n]³⁺ cationic pillars. The thermal stability, reversible solvent uptake, photoluminescence properties and magnetic studies of these compounds were carried out. In addition, theoretical investigations were carried out in compound 1 for the existence of a near-planar pentamer water cluster.