A series of counter cation-dependent tetra β-diketonate mononuclear lanthanide(iii) single-molecule magnets and immobilization on pre-functionalised GaN substrates by anion exchange reaction

Abstract

A series of mononuclear lanthanide complexes with the formula [Hex₄N][Ln(DBM)₄] (1Ln) (Ln = Nd and Tb), [But₄N][Dy(DBM)₄] (2), [Et₄N][Dy(DBM)₄] (3), [PhCH₂N(CH₃)₃][Dy(DBM)₄] (4) and [Hex₄N][Dy(TTA)₄] (5) formed by four β-diketonate ligands (i.e. DBM = dibenzoylmethane, TTA = 2-thenoyltrifluoroacetone) and four organic counter ammonium cations (i.e. Hex₄N = tetrahexylammonium, But₄N = tetrabutylammonium, Et₄N = tetraethylammonium and PhCH₂N⁺(CH₃)₃) were structurally and magnetically characterized. The organic ammonium as contactless cation pairs with [Ln(β-diketonate)₄]⁻¹ moieties, the impact of different remote organic cations and the first coordination sphere comprising distinct β-diketonates on their SMM performance were elaborately studied. This is an efficient method by virtue of the interaction of the remote organic ion pair to modulate their single-molecule magnetic (SMM) properties. More importantly, the tetrakis β-diketonate Dy(III) anion can be almost intactly grafted on functional GaN substrate through an anion exchange reaction, resulting in diminishing slow magnetic relaxation behavior, which presents potential application in future SMM devices.