Synthesis, Crystal Structure and Magnetic Properties of Heteropolynuclear Re^IVM^II Complexes Based on the Robust [ReCl₅(pyzCOO)]^2– Unit (pyzCOO = 2‐pyrazinecarboxylate)

Abstract

Abstract:The syntheses, crystal structures and magnetic properties of four rhenium(IV) compounds of formulae (2) and Co (3)] and {[ReCl 5 (μ 3 -pyzCOO)] 2 Mn 2 (dmphen) 3 } n (4) (NBu 4 = tetra-n-butylammonium cation, pyzCOOH = 2-pyrazinecarboxylic acid, dmphen = 2,9-dimethyl-1,10-phenanthroline) are reported herein.

Enhancement of Intermolecular Magnetic Exchange through Halogen···Halogen Interactions in Bisadeninium Rhenium(IV) Salts

“…Anionic halorhenate(IV) salts are very appealing because of their unique magnetic properties, which include both slow relaxation and quantum tunneling of the magnetization and long-range magnetic order originating from single-ion or cooperative magnetic behaviours, respectively. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] In particular, the simple hexahalorhenate(IV) salts [Re IV X6] 2-(X = F, Cl, Br, and I) of paramagnetic and diamagnetic cations generally show significant short-range intermolecular ferro-or antiferromagnetic interactions, which are mainly transmitted through relatively short intermolecular Re-X•••X-Re contacts, occasionally leading to collective magnetic phenomena such as ferromagnetism and spin canting (weak ferromagnetism). [47][48][49][50][51][52][53][54][55][56][57][58][59] Herein we report the synthesis and magneto-structural characterization of two novel Re IV compounds of general formula [H2ade]2[Re IV X6]X2•4H2O [H2ade 2+ = 9H-adenine-1,7-diium; X = Cl (1) and Br (2)].…”

“…to the presence of intermolecular interactions and/or zero-field splitting (zfs) effects. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] The presence of a maximum in the magnetic susceptibility at ca. (Figs.…”

“…Anionic halorhenate­(IV) salts are very appealing because of their unique magnetic properties, which include both slow relaxation and quantum tunneling of the magnetization and long-range magnetic order originating from single-ion or cooperative magnetic behaviors, respectively. − In particular, the simple hexahalorhenate­(IV) salts [Re IV X 6 ] 2– (X = F, Cl, Br, and I) of paramagnetic and diamagnetic cations generally show significant short-range intermolecular ferro- or antiferromagnetic interactions, which are mainly transmitted through relatively short intermolecular Re–X···X–Re contacts, occasionally leading to collective magnetic phenomena such as ferromagnetism and spin canting (weak ferromagnetism). − …”

Magneto-structural correlations in a family of ReIVCuII chains based on the hexachlororhenate(iv) metalloligand

“…the effect of cation size on intermolecular interactions and T c ), the role of the [ReCl 6 ] 2− anion has been largely limited to that of synthetic precursor. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] Indeed, a common strategy for the creation of new Re IV complexes is the functionalisation of the [ReCl 6 ] 2− anion through halide exchange with ligands such as heterocyclic amines, pseudo halides such as cyanide, or chelates such as the oxalate anion. 6,[10][11][12][13] These species have subsequently been employed as metalloligands for the creation of larger oligomers.…”

“…6,[10][11][12][13] These species have subsequently been employed as metalloligands for the creation of larger oligomers. [14][15][16][17] More recently, several 1D chains based on the Re IV ion have been reported. For example, the [trans-ReCl 4 (CN) 2 ] 2− anion was used to construct the Single-Chain Magnet (SCM) {[Fe(DMF) 4 ][trans-ReCl 4 (CN) 2 ]} n which displays a coercive field of 1 T at T = 1.8 K, 9 the [ReF 6 ] 2− anion was used for the first time in 2014 as a metalloligand for the synthesis of the 1D complex {[Ni(Vim) 4 ][ReF 6 ]} n which exhibits strong ferromagnetic exchange between neighbouring metal ions, 20 while the {[Cu( pyim) 2 ][ReCl 4 (ox)]} n chain ( pyim = 2-(2′-pyridyl)imidazole and ox = oxalate) exhibits ferrimagnetic behaviour due to the presence of two different magnetic exchange interaction pathways (O, Cl) between the Re IV and Cu II ions.…”