Magnetism of Linear [Ln₃]⁹⁺ Oxo-Bridged Clusters (Ln = Pr, Nd) Supported inside a [R₃PR′]⁺ Phosphonium Coordination Material

Abstract

Two new isostructural phosphine coordination materials, Ln-PCM-21 (Ln = Pr, Nd), have been obtained using a tris(p-carboxylated) methyltriphenylphosphonium ligand that is formally dianionic when triply deprotonated, allowing access to materials based on uncommon metal-to-ligand ratios. The polymers of the formula [Ln3(mptbc)4]X·solv (X = Cl(-), NO3(-)) are cationic and contain unusual, linear oxo-bridged [Ln3](9+) clusters. Magnetic susceptibility data for both the Pr and Nd analogues has been compared to models based on three contrasting approaches.

Magnetism and Luminescence of a MOF with Linear Mn3 Nodes Derived from an Emissive Terthiophene-Based Imidazole Linker

“…The solid-state magnetic properties of 6 were also assessed since the near [Mn 3 ] 6+ nodes are structurally unusual and could give rise to interesting magnetic ordering. More specifically, linear M 3 oxo-bridged clusters are interesting model systems to study for their potential spin frustration [ 26 ]. In this case, the magnetic network of each [Mn 3 ] 6+ cluster can be simplified to have one common J parameter between Mn1 and Mn2, and it can be assumed that the single atom-O bridges will facilitate greater magnetic superexchange than the Mn-OCO-Mn bridges (see Figure 2 b).…”

Phosphonium salts and P-ylides

“…18 Wood, Humphrey and co-workers obtained two new isostructural materials by the reaction of Pr and Nd complexes with a tris(p-carboxylated) methyl-triphenylphosphonium ligand. 19 The later allowed access to materials with uncommon metal-to-ligand ratios. A series of new mononuclear and heteronuclear complexes of carboxylate phosphonium betaines with biologically important metals (Zn(II), Cd(II), Hg(II) and Cu(II)) were obtained by Galkina et al 20 The ligand binding mode was clarified by X ray diffraction (XRD).…”

Phosphonium salts and P-ylides

“…18 Wood, Humphrey and co-workers obtained two new isostructural materials by the reaction of Pr and Nd complexes with a tris(p-carboxylated) methyl-triphenylphosphonium ligand. 19 The later allowed access to materials with uncommon metal-to-ligand ratios. A series of new mononuclear and heteronuclear complexes of carboxylate phosphonium betaines with biologically important metals (Zn(II), Cd(II), Hg(II) and Cu(II)) were obtained by Galkina et al 20 The ligand binding mode was clarified by X ray diffraction (XRD).…”