Solvothermal synthesis, characterization and properties of [ReCl5(py)]− complex with T (Néel) of 5.5 K

Abstract

The synthesis and properties of a rhenium(IV) complex with pyridine as a ligand are presented. The complex, with the formula (2-methyl-pyH)[ReCl 5 (py)] 4,4 0 -bipyridyl 1 has been characterized by elemental analysis, IR spectroscopy, SQUID and X-ray measurements. The single crystal X-ray structure of 1 shows that the rhenium center is of distorted octahedral environment, consisting of five chloride atoms and one pyridine ligand. The solid-state magnetic measurements show antiferromagnetic interactions with T (Néel) of 5.5 K.

Deciphering the origin of giant magnetic anisotropy and fast quantum tunnelling in Rhenium(IV) single-molecule magnets

“…Despite several years of comprehensive experimental efforts in designing Re(IV) ion-based SMMs/SCMs, the origin of giant magnetic anisotropy is not well understood 39 . As in most of the cases, the axial ZFS ( D ) values are extracted using magnetization measurements, which are known to be insensitive to the sign and strength of the D parameter 41 43 44 45 46 47 48 49 50 51 . On other hand, the most promising high frequency-electron paramagnetic resonance (HF-EPR) technique has its own limitation, where the sign can be accurately determined but such large magnitude of D are often difficult to estimate 39 .…”

“…The goal of the present communication is to gain a thorough understanding of the magnetic anisotropy in six coordinate Re(IV) complexes using state-of-the-art ab initio calculations. By modelling structurally diverse 13 mononuclear six coordinate Re(IV) complexes 39 41 43 44 45 46 47 48 49 50 51 , we aim to answer the following intriguing questions (i) What is the suitable theoretical methodology to compute ZFS parameters in 5 d transition metal ions such as Re(IV) complexes? (ii) What is the origin of giant D values and is there a correlation between the nature of the donor atoms and the sign of the D values in these complexes?…”

Synthesis and structural characterization of the novel unusual oxido-bridged rhenium complex with Re atoms in two different coordination environments

“…Most plausible, although not unambiguous oxidation state assignment is "Re III/IV ". The complex has been obtained by means of a solvothermal method, which seems to be a rich and promising, yet not completely explored source of rhenium complexes at different oxidation states [11]. According to our best knowledge, the only reported examples of binuclear complexes with X-ray structures interpreted as "Re III, IV " mixed-valence species include [Re III,IV 2 (μ-O)Cl 2 (tpa) 2 ](SbF 6 ) 3 (tpa = tris(2-pyridylmethyl)amine [12]) (1) and [Re III,IV 2 (μ-O)Cl 2 (Metpa) 2 ] (PF 6 ) 3 [13] (2).…”