| Summary: | 碩士 === 輔仁大學 === 化學系 === 107 === Three heptanuclear manganese clusters [Mn7(OH)2(dhap)2- (N3)2(MeCN)6(H2O)2] ･1.5(MeCN)･5(ClO4) and [Mn7(OH)2(dhap)2(N3)2 (MeCN)4(H2O)4] ･1.5(MeCN)･5(ClO4) (1) [Mn7(OH)2(dhap)2(N3)3 (MeCN)4(ClO4)2] ･2(MeCN)･2 (ClO4) (2) (dhapH¬4 = 2,6-bis[N,N-di(hydroxyl -ethyl)aminomethyl]pyridine) are self-assembled from dhapH4 /NaClO4･H2¬O/Mn(ClO4)2･6H2¬O, dhapH4/Mn(ClO4)2･6H2¬O and dhapNaBr /Mn(ClO4)2･6H2¬O systems with NaN3 and Et3N in MeCN, respectively. Three complexes are all mixed-valence hepta-nuclear manganese center [MnII4MnIII3(OH)2]15+. Then , all manganese atoms in these two structure are assembled by two ligand with azide bridged .The differences between (1) and (2) is that (1) is single molecule structure , and then (2) is one-dimensional chain. At first before , we think that (1),(2) are pure substances they can be measured magnetic susceptibilities. However, the complex is a mixture , contains (1) and (2) . After all, these two complex separated and successfully measure XRD data.
The dc magnetic susceptibilities of complexes (2) has strong ferromagnetic interactions and weak interchain antiferro-magnetic interactions. And, complexes (2), out-of-phase signals in ac magnetic susceptibilities and magnetic hysteresis loop studies with are energy barrier ofeff =35.084 cm-1, and ×s, that confirmed both Mn7 are new single-chain magnet.
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