Osmium-Nitrosyl Oxalato-Bridged Lanthanide-Centered Pentanuclear Complexes - Synthesis, Crystal Structures and Magnetic Properties

TL;DR

This study synthesizes and characterizes a series of pentanuclear heterometallic complexes with lanthanide and osmium centers, revealing their structures and magnetic properties through various spectroscopic and crystallographic techniques.

Contribution

It introduces new lanthanide-osmium complexes with detailed structural and magnetic characterization, expanding understanding of their coordination chemistry and properties.

Findings

Complexes feature lanthanide or yttrium cores bridged by oxalato ligands to osmium-nitrosyl units.

Central metal ions exhibit coordination numbers of eight or nine.

Structural analysis confirms a lanthanide or yttrium core with specific bridging ligands.

Abstract

A series of pentanuclear heterometallic coordination compounds of the general formula (Bu 4 N) 5 [Ln{Os(NO)($\mu$-ox)-Cl 3 } 4 (H 2 O) n ] [Ln = Y (for 2) and Dy (for 3) when n = 0; Ln = Dy (for 3), Tb (for 4), and Gd (for 5) when n = 1] were synthesized by the reaction of the precursor (Bu 4 N) 2 [Os(NO)(ox)-Cl 3 ] (1) with the respective lanthanide(III) (Gd, Tb, Dy) or yttrium(III) chloride. For the five new complexes, the coordination numbers eight or nine are found for the central metal ion. The compounds were fully characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction analysis, magnetic susceptibility measurements, and ESI mass spectrometry. In addition, compound 1 was studied by UV/Vis spectroscopy and cyclic voltammetry. The X-ray dif-fraction analyses revealed that the anionic complexes consist of a lanthanide or yttrium core bridged through oxalato li-gands to four octahedral osmium-nitrosyl moieties. This picture , in which the central ion is eight-coordinate, holds for