DISIGN AND CONSTRUCTION OF ORGANIC FERROMAGNET AND THEIR CRYSTAL DESIGN.

为了获得有机铁磁体，人们采用了两种方法：(I)分子内方法和(Ii)分子间方法。(I)以前的ESR研究表明，由相应的重氮前驱体在低温下成功地光化学生成了支链六碳和二十九碳烯类化合物，表明它们的磁性行为是自旋玻璃或超顺磁性的。虽然人们已经进行了大规模的卡宾前体的制备，以进一步了解这一现象，但在AC-SQUID仪器上的初步实验表明，在极其稀薄的条件下，仪器的灵敏度相当令人失望，这肯定是卡宾不与反铁磁性相互作用的必要条件。制备这些卡宾前体的关键步骤是胺催化的乙炔基酮的环三聚反应，其机理是通过使用取代的芳基乙炔基酮涉及芳基2-氨基乙烯酮来确定的。环He…更多的沙卡宾被认为是具有蜂窝状结构的理想聚卡宾的部分骨架，证明了S的自旋量子数为6，这与理论上的预期一致。这一结果与支链六苯异构体的结果一起清楚地表明，交替的烃分子的自旋多重性是由(3，5-二羟基苯基)硝基氮氧化物的拓扑对称性决定的。(Ii)对(3，5-二羟基苯基)硝基氮氧化物进行了初步的X-射线结构分析，表明羟基对分子的二维排列是有效的，合成了几个(羟基萘基)硝基氮氧化物异构体，并进行了磁性观察和X射线晶体分析。发现其中一些自由基在极低温度下表现出铁磁行为。对这些分子的进一步研究正在进行中。较少

In order to achieve an organic ferromagnet, two approaches to it were adopted ; (i) intrarmolecular approach and (ii) intermolecular one.(i) Previous ESR studies on branched-chain hexa-and nonacarbenes, successfully generated photochemically at a cryogenic temperature from the corresponding diazo precursors, suggested their magnetic behaviors as spin-glass or super-paramagnetic. Though large scale preparations of the carbene precursors were carried out to get further insights into the phenomenon, preliminary experiments on an AC-SQUID instrument revealed that the instrumental sensitivity was quite disappointing under an extremely dilute condition which was definitely required for the carbene not to interact antiferromagnetically.The key step for the preparation of those carbene precursors was an amine-catalyzed cyclo-trimerization reaction of ethynyl ketones, whose mechanisms were determined by the use of substituted aryl ethynyl ketones to involve aryl 2-aminoethenyl ketones.Cyclic he … More xacarbene which might be assumed to have a partial skeleton of an ideal polycarbene with honycomb structure was successfully generated to show that the spin quantum number S is 6 as expected theoretically. This result together with those of isomeric branched-chain hexacarbenes clearly demonstrates that the spin multiplicity of the alternant hydrocarbon molecules is determined by the topological symmetry of the pi-bond sequence.(ii) As preliminary X-ray structural analysis on (3,5-dihydroxyphenyl) nitronyl nitroxide indicated the hydroxyl group to be effective in arranging the molecules two dimentionally, syntheses, magnetic observations, and x-ray crystallographic analyzes of several (hydroxynaphthyl) nitronyl nitroxide isomers were performed along with those of the corresponding (bromophenyl)- and (bromonaphthyl) nitronyl nitroxide radicals. It was found that some of these radicals showed ferromagnetic behaviors at extreme low temperatures. Further studies on these molecules are under way. Less