Periodicity of Single‐Molecule Magnet Behaviour of Heterotetranuclear Lanthanide Complexes across the Lanthanide Series: A Compendium

Abstract

Acetato‐bridged palladium‐lanthanide tetranuclear heterometallic complexes of the form (Pd2Ln2(H2O)2(CH3COO)10)·2CH3COOH (Ln2 = Ce2(1), Pr2(2), Nd2(3), Sm2(4), Tb2(5), Dy2(6), Dy0.2Y1.8(6''), Ho2(7), Er2(8), Er0.24Y1.76(8''), Tm2(9), Yb2(10), Y2(11)) were synthesised and characterised by experiment and theoretical techniques. All complexes containing the Kramers lanthanide ions (Ln3+) (Ce (1), Nd(3), Sm(4), Dy(6), DyY(6''), Er(8), ErY(8''), Yb(10)) showed field‐induced slow magnetic relaxation, characteristics of single‐molecule magnetic and purely of molecular origin. In contrast all synthesised non‐Kramers lanthanide ions (Ln3+ = Pr(2), Tb(5), Ho(7), Tm(9), Y3+(11) is diamagnetic and non‐lanthanide) did not show any slow magnetic relaxation. The variation in the electronic structure as well as accompany consequences across the complexes representing all Kramers and non‐Kramers lanthanide ions were investigated. The origin of the magnetic properties and the extent to which the axial donor‐acceptor interaction involving the lanthanide ions and an electron‐deficient dz2 of palladium affects the observed magnetic and electronic properties across the lanthanide series are presented. We report unique consistent electronic and magnetic properties of isostructural complexes spanning the lanthanide series with property variant dependent on whether the ions are Kramers or non‐Kramers.