Functionalized Trigonal Lanthanide Complexes: A New Family of 4f Single-Ion Magnets

Abstract

We report the synthesis, characterization, and magnetic properties of eight neutral functionalized trigonal lanthanide coordination complexes LnL with Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8). These were prepared through a one-pot synthesis where, first, the ligand H3L was synthesized in situ through a Schiff base reaction of tris(2-aminoethyl)amine with 2,6-diformyl-p-cresol. Following addition of Ln(OTf)3·xH2O and base, LnL was obtained. Powder X-ray diffraction confirms that all complexes are isostructural. LnL contain pendant, noncoordinating carbonyl functions that are reactive and represent direct anchoring points to appropriately functionalized surfaces. Furthermore, these reactive carbonyl functions can be used to postfunctionalize LnL: for example, with aromatic π systems. We present herein the Schiff base condensation of 7 with benzylamine to yield 9 as well as the characterization and magnetic properties of 9. Our study establishes LnL as a truly versatile module for the surface deposition of Ln-based single-ion magnets.