学位論文

スチルベン骨格をもつニトロニルニトロキシド類とその遷移金属錯体の合成ならびに磁気特性

NITRONYL NITROXIDESWITH ASTILBENE SKELETON AND THEIR TRANSITION METAL COMPLEXES : THEIR STRUCTURES AND MAGNETIC PROPERTIES

jpn

2008-03-24

Not Applicable (or Unknown)

2008-03-24

修士(工学)

工学研究科物質化学専攻; 指導教授: 中村暢男

With an expectation of some degree of intermolecular π-π stacking to transmit the spin-spin exchange interactions, the three nitronyl-nitroxide radicals with the trans- and cis-stilbene skeletons(1), (2), and (2’), and their corresponding transition metal complexes (Metal = Mn(a) and Co(b)) were prepared. The radicals behaved, as revealed by their magnetic susceptibility measurements, in a paramagnetic manner within an ordinary temperature range and in an antiferromagnetic fashion at very low temperatures. Complexation of the radical 1 with the metal complexes M(hfac)2 (M = Mn, Co) afforded one-dimensional zigzag-type ferrimagnetic chains of cis-orientaion about the metal, with the shortest interchain distances of 10.6 Å and 10.4 Å for the Mn- and Co-complexes, respectively. The ferrimagnetic characters shown by the radical 1a, the Mn(hfac)2 complex with the radical 1, were analyzed by the Seiden’s ferrimagnetic chain model to afford J/kB = -380 K and zJ/kB = -0.098 K. FCM and ZFCM observations of the Mn complex 1a revealed the ferromagnetic phase transition temperatures to be 4.0 K. The structures and the susceptibility data for 2 and 2’ are also reported.

Thesis