Intramolecular Ferromagnetism in Di-Nuclear 3 d-Transition-Metal Single-Molecule Magnets by Pseudo-Serial Arrangement.

Di-nuclear citrate complexes, [CH6 N3 ]2 [M2 (citH)2 (H2 O)4 ] ⋅ 2H2 O (citH4 =citric acid; M=FeII (Fe-2), CoII (Co-2), and NiII (Ni-2)), are synthesized. The ligand, citH3- , is deprotonated only at the three carboxy groups, which is different from the previously reported tetra-nuclear structures with cit4- ligands. Magnetic measurements reveal that these complexes have intramolecular ferromagnetism with J=∼0 cm-1 (Ni-2), 0.02 cm-1 (Co-2), and 0.04 cm-1 (Fe-2). Co-2 and Fe-2 show slow magnetic relaxation, and are field-induced SMMs with activation energy of spin-reversal Ueff =27 cm-1 (Co-2) and 4.2 cm-1 (Fe-2). Density functional theory calculations indicate that the uniaxial anisotropy along the z-axis of each metal ion center forms the pseudo-serial arrangement, leading to intramolecular ferromagnetism via the magnetic dipole interaction. This work demonstrates the creation of ferromagnetic SMMs by the magnetic dipole engineering of 3d di-nuclear metal ion centers.

Isolation of epidermal cells and cDNA cloning of TNF decoy receptor 3 of conger eel, Conger myriaster.

By using EDTA and a trypsin solution, we established a method for isolating the epidermal cells of the conger eel, Conger myriaster. We then identified TNF decoy receptor (DcR) cDNA in the species from a suppression subtractive hybridization library prepared from the epidermal cells stimulated with LPS. The full-length cDNA of conger TNF DcR (conDcR) consisted of 1479 base pairs, and the protein comprised 286 amino acid residues. Phylogenetic analysis indicated that conDcR was clustered into a DcR3 branch. ConDcR is likely to act as an important immune-regulating factor in inhibiting the apoptosis-inducing effect of TNF in the skin of conger eel.