Magneto-structural correlations in dirhenium(iv) complexes possessing magnetic pathways with even or odd numbers of atomsElectronic supplementary information (ESI) available. CCDC 1557650-1557653. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt02612a

• Main Authors: Pedersen, Anders H, Julve, Miguel, Martínez-Lillo, José, Cano, Joan, Brechin, Euan K
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt02612a

The employment of pyrazine (pyz), pyrimidine (pym) and s -triazine (triz) ligands in Re IV chemistry leads to the isolation of a family of complexes of general formula (NBu 4 ) 2 [(ReX 5 ) 2 (μ-L)] (L = pyz, X = Cl ( 1 ) or Br ( 2 ); L = pym, X = Br ( 3 ); L = triz, X = Br ( 4 )). 1-4 are dinuclear compounds where two pentahalorhenium( iv ) fragments are connected by bidentate pyz, pym and triz ligands. Variable-temperature magnetic measurements, in combination with detailed theoretical studies, uncover the underlying magneto-structural correlation whereby the nature of the exchange between the metal ions is dictated by the number of intervening atoms. That is, the spin-polarization mechanism present dictates that odd and even numbers of atoms favour ferromagnetic (F) and antiferromagnetic (AF) exchange interactions, respectively. Hence, while the pyz ligand in 1 and 2 mediates AF coupling, the pym and triz ligands in 3 and 4 promote F interactions. Spin-polarization enforces either ferro- or antiferromagnetic exchange interactions between Re IV ions with odd or even numbers of intervening atoms.