A MnII6MnIII6 single-strand molecular wheel with a reuleaux triangular topology: Synthesis, structure, magnetism, and DFT studies
Ημερομηνία
2013Συγγραφέας
Zartilas, Sotiris M.Papatriantafyllopoulou, Constantina
Stamatatos, Theocharis C.
Nastopoulos, Vassilios
Cremades, E.
Ruiz, E.
Christou, George
Lampropoulos, Christos
Tasiopoulos, Anastasios J.
Source
Inorganic chemistryVolume
52Issue
20Pages
12070-12079Google Scholar check
Metadata
Εμφάνιση πλήρους εγγραφήςΕπιτομή
The use of the anion of 3-methyl-1,3,5-pentanetriol (mpt3-) in manganese carboxylate chemistry has afforded the new MnII/III 12 cluster [MnII6MnIII 6(mpt)6(CH3CO2)12(py) 6]·3CH3CN (1·3CH3CN). Complex 1 was isolated in moderate yield by the reaction of Mn(CH3CO 2)2·4H2O and H3mpt in a 2.6:1 molar ratio in a solvent mixture of acetonitrile and pyridine. The structure of 1 consists of alternating [MnII2(CH3CO 2)3(py)]+ and [MnIII 2(μ-OR)2(CH3CO2)(py)] 3+ dimeric units (three of each dimer), linked at each end by two alkoxo and one acetate bridges the mpt3- ligands adopt the η2:η2:η2:μ4 coordination mode. The overall metal topology of this new Mn12 wheel resembles a guitar plectrum, or a Reuleaux triangle. Complex 1 displays an unprecedented structural topology, being the first example of a Mn II6MnIII6 wheel constructed from alternating homovalent dimers and the only known Mn12 loop with the trigonal symmetry of a Reuleaux triangle (all other reported loops were ellipsoids). Variable-temperature, solid-state direct- and alternating-current magnetization studies were carried out on complex 1, revealing the presence of antiferromagnetic exchange interactions between the metal ions in the molecule, which lead to a spin ground-state value S = 0 the exchange coupling parameters J were calculated using density functional theory employing a hybrid B3LYP functional. © 2013 American Chemical Society.