Novel mononuclear and 1D-polymeric derivatives of lanthanides and (η⁶-benzoic acid)tricarbonylchromium: synthesis, structure and magnetism

Abstract

Novel derivatives of lanthanides and (η6-benzoic acid)tricarbonylchromium were synthesized and characterized; complexes of Tb, Dy, Er and Yb exhibit SMM behavior.

Crystal Structure and Magnetic Properties of Peacock–Weakley Type Polyoxometalates Na9[Ln(W5O18)2] (Ln = Tm, Yb): Rare Example of Tm(III) SMM

“…15 kOe, a very smooth augmentation to reach of 3.6 µ B (1) and 2.0 µ B (2) at 50 kOe; no hysteresis was observed. These values are similar to those reported for Tm(III) [12,14] and Yb(III) [30,31] systems, and they confirm that there is an important splitting of the ground J manifold by the ligands [32,33]. For the ground state with a pure M J term, the saturation magnetization is given by M S = 1 2 × J × g J .…”

Mononuclear Dysprosium Thiocyanate Complexes with 2,2′‐Bipyridine and 1,10‐Phenanthroline: Synthesis, Crystal Structures, SIM Behavior, and Solid‐Phase Transformations

“…In terms of an electrostatic model, the following charge distribution was used: for the NCS – anions, the charge was (–1/3):(–1/3):(–1/3) (N/C/S), bpy and phen were considered as neutral moieties, and the partial charges on the coordinated water molecules were 0:0, +1/8:(–1/4), +1/4:(–1/2), +1/2:(–1) (H/O). As shown previously, the partial charges on electroneutral, as a whole, water molecules may lead to a substantial difference in the magnetization‐reversal barriers. The results of calculations are summarized in Tables S11 and S12.…”

Preparation and properties of uncommon Cd‐Mn carboxylate complexes—per se and as precursors for CdMn2O4‐based ceramics

“…Such a difference, in turn, originates from weaker Coulomb interactions between Cd 2+ and both of acac − ligands comparing with similar Ln 3+ − acac − interactions within {Ln (acac) 3 } moieties. This assumption is supported by the fact that for previously studied similar systems with 1Ln(acac) 3 :1RCOOH molar ratio, [ 19 ] no by‐products with other ratios were formed irrespectively of R composition.…”

“…Previously, the efficiency of such an approach, that is, of stepwise acac − to RCOO − substitution, has been demonstrated on a variety of heteroleptic Ln 3+ complexes. Mononuclear, [ 19a,b ] dinuclear [ 19c ] and 1D‐polynuclear Ln carboxylate complexes [ 19d ] derived from corresponding tris ‐acetylacetonates were isolated and studied, and the acac − to RCOO − ratio in resulting complexes always corresponded to the stoichometry of the reaction. If it is possible to expand such an approach for complexes of d ‐elements, for example, Cd 2+ , it will obviously rise new opportunities to control structures and, hence, properties of heteroleptic complexes formed by these elements.…”