Incorporating palladium in the first coordination sphere of acetato-bridged lanthanoid complexes, [Pd Ln (H O) (AcO) ]⋅2 AcOH (Ln=Gd (1), Y (2), Gd Y (3), Eu (4)), led to significant bonding interactions between the palladium and the lanthanoid ions, which were demonstrated by experimental and theoretical methods. We found that electron density was donated from the d Pd ion to Gd ion in 1 and 3, leading to the observed slow magnetic relaxation by using local orbital locator (LOL) and X-ray absorption near-edge structure (XANES) analysis. Field-induced dual slow magnetic relaxation was observed for 1 up to 20 K. Complex 3 and frozen aqueous and acetonitrile solutions of 1 showed only one relaxation peak, which confirms the role of intermolecular dipolar interactions in slowing the magnetic relaxation of 1. The slow magnetic relaxation occurred through a combination of Orbach and Direct processes with the highest pre-exponential factor (τ =0.06 s) reported so far for a gadolinium complex exhibiting slow magnetic relaxation. The results revealed that transition metal-lanthanoid (TM-Ln) axial interactions indeed could lead to new physical properties by affecting both the electronic and magnetic states of the compounds.

Heterometallic Gd-Pt complexes ([Gd Pt (H O) (SAc) ] (SAc=thioacetate), [Y Gd Pt (H O) (SAc) ], and [Gd Pt (H O) (SAc) ]⋅7 H O have been synthesized. The crystal structures and DFT calculations indicated a Gd-Pt heretometallic bond. Single-crystal ESR spectra determined the direction of magnetic anisotropy as direction of the Gd-Pt bond. In other words, the Gd-Pt bond dictates the direction of magnetic anisotropy. The heterometallic Gd-Pt bond lowers the symmetry of the Gd ion, splitting the Kramers doublet in a dc field. Thus, we observed clear field-induced slow magnetic relaxation of [Y Gd Pt (H O) (SAc) ] up to 36 K. The relaxation process was determined to be a direct process.

The first three-dimensional (3D) conductive single-ion magnet (SIM), (TTF)2[Co(pdms)2] (TTF = tetrathiafulvalene and H2pdms = 1,2-bis(methanesulfonamido)benzene), was electrochemically synthesized and investigated structurally, physically and theoretically. The quite close oxidation potential between neutral TTF and the coordination precursor, (HNEt3)2[M(pdms)2] (M = Co, Zn) causes multiple charge transfers (CTs) between SIM donor [M(pdms)2] nand the TTF •+ acceptor as well as an intra-donor CT from the pdms ligand to Co ion upon electrocrystallization. Usually TTF works as a donor, whereas in our system, TTF works as both a donor and an accepter due to the close oxidation potentials. Furthermore, the [M(pdms)2] ndonor and TTF •+ acceptor are not segregated but strongly interact with each other, contrary to reported layered donor-acceptor electrical conductors. The strong intermolecular and intramolecular interactions, combined with the CT, cause relatively 2 high electrical conductivity to very low temperature. Furthermore, SIM behaviour with slow magnetic relaxation and opening of hysteresis loops were observed. (TTF)2[Co(pdms)2] (2-Co) is an excellent building block for preparing new conductive SIM.