Search

Structural, magnetic and theoretical studies of three octahedral mononuclear DyIII complexes with triphenylphosphine oxide and halide ligands are reported. The Cl− and Br− analogues exhibit SMM behavior with energy barriers of 49.1 K and 70.9 K, respectively under a small dc field. Ab initio calculations were performed, the results of which predict higher energy barriers for iodide containing SMMs. [ABSTRACT FROM AUTHOR]

The initial use of quinoline-2-aldoxime (qaoH) and 2,6-diacetylpyridine dioxime (dapdoH 2 ) in heterometallic Mn–Ca chemistry has afforded a mixed-valence {Mn II/III 22 Ca 2 } cluster containing several {Mn 4 CaO x } subunits and a ‘butterfly’-like {Mn IV 2 Ca 2 } complex, respectively. The one-pot reaction of Mn(O 2 CPh) 2 ·2H 2 O and Ca(O 2 CPh) 2 ·H 2 O with qaoH and NEt 3 in a 1:1:1:1 molar ratio in a solvent mixture comprising MeCN/MeOH gave complex [Mn 22 Ca 2 O 14 (OH) 4 (OMe) 6 (O 2 CPh) 22 (qao) 2 (MeCN) 2 (H 2 O) 4 ](OH) 2 ( 1 ; 6Mn II /16Mn III ) in 20% yield. A similar reaction with that of 1 , albeit with Mn(O 2 CPh) 2 ·2H 2 O and Ca(NO 3 ) 2 ·4H 2 O in the presence of dapdoH 2 and NEt 3 , in a molar ratio of 1:1:2:2 in MeCN/MeOH, led to the smaller nuclearity complex [Mn 2 Ca 2 (OMe) 2 (NO 3 ) 2 (dapdo) 4 ] ( 2 ; 2Mn IV ) in 40% yield. The reported compounds demonstrate structural and magnetic relevance to both low- and high-valent states of the OEC. [ABSTRACT FROM AUTHOR]

The synthesis, characterization, and stability study of the first uranium complex bearing 2,6-diacetylpyridine dioxime (dapdoH 2 ) is reported. The dimeric complex [UO 2 (dapdoH)Cl] 2 is stable in solution as shown by ESI-MS and NMR spectrometry, and its solid-state structure was further analyzed by X-ray crystallography, IR, Raman and luminescence studies. [ABSTRACT FROM AUTHOR]

The targeted replacement of acetate groups in the optically inactive [MnIII3O(O2CMe)3(mpko)3](ClO4) single-molecule magnet with their naphthalene, anthracene, and pyrene fluorescent analogues has led to three new emissive SMMs with enhanced photo-luminescence properties and potential applications in the field of molecular electronics. [ABSTRACT FROM AUTHOR]

Abstract: The combination of azide, carboxylate (pivalate and in situ generated formate) and triethanolamine ligands in higher oxidation state Mn cluster chemistry has afforded a new pentadecanuclear, mixed-valence(II,III) compound with a large S and a negative D value. The unprecedented [MnII 2MnIII 13] cluster exhibits frequency-dependent out-of-phase (χ M″) signals, characteristics of the superparamagnetic-like slow relaxation of an SMM. [Copyright &y& Elsevier]

The synthesis, structure, and magnetochemical characterization of the largest manganese oxime cluster are reported. The Mn15/2-pyddinealdoxime compound is mixed-valence (Il/Ill) and possesses an irregular structural motif with a novel Mn/O core. The oximato-bridged cluster exhibits an S = 6 ground state and a negative magnetoanisotropy. [ABSTRACT FROM AUTHOR]