DISIGN AND CONSTRUCTION OF ORGANIC FERROMAGNET AND THEIR CRYSTAL DESIGN.

为了获得有机铁磁体，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研究支链六和nonacarbenes，成功地产生在低温下从相应的重氮前体的光化学，建议其磁行为的自旋玻璃或超顺磁性。虽然进行了卡宾前体的大规模制备以进一步了解该现象，在AC-SQUID仪器上的初步实验表明，在极稀的条件下，仪器的灵敏度相当令人失望，而极稀的条件是卡宾不发生反铁磁作用的必要条件。乙炔基酮的三聚反应，其机理通过使用取代的芳基乙炔基酮来确定，包括芳基2-氨基乙烯基酮。 关于我们 成功地制备了一种具有Honycomb结构的理想聚卡宾的部分骨架的xacarbene，表明自旋量子数S与理论预期的一样为6。这一结果与同分异构支链六卡宾的结果一起清楚地表明，交替烃分子的自旋多重性是由π键序列的拓扑对称性决定的。(ii)作为初步的X-射线结构分析（3，5-二羟基苯基）硝酰基氮氧化物表明，羟基是有效地安排分子的二维，合成，磁性观察，和X-射线晶体学分析的几个（羟基萘基）硝酰基氮氧化物异构体进行沿着与相应的（溴苯基）和（溴萘基）硝酰基氮氧化物自由基。结果表明，这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。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