AbstractPolymer anchored sulfonylazide is compared with its efficiency in the diazogroup transfer reaction of tosylazide. The resulting yields with the polymeric reaction are slightly lower than with tosylazide. However the greater thermostability of polymeric sulfonyl azide and its workup procedure make this alternative very attractive for synthesis. The reaction of polymeric sulfonyl azide with cyclic polyenes gives very small yields compared with the monomeric reaction. The attempt to generate diazocyclononatetraene by an alternative route leads only to the secondary product namely indene. At low temperature, and intermediate diazo-compound is, however, observed, which is tentatively assigned to structure 12.
ture, turn bright yellow on cooling, and vice versa, i. e. they are thermochromic. 3e is yellow and shows no thermochromism. The change in color of the Co3+-complexes with decreasing temperature is accompanied by a decrease in paramagnetism.The magnetic moments of 3a-d in the solid state lie between 1.2 and 5.3 vB at 300K and between 0.3 and 0.9 pB at 4K. In this temperature range, 3e is diamagnetic. The change in low spin-high spin equilibrium with temperature can be followed in solution by 3'P-NMR spectroscopy (Fig. I). Optimized thermodynamic parameters AGO, AH', and AS" for the low-spin-high-spin transition can be determined from the measurements if the following temperature-dependence of 6 is (Table I) :
la-e: Die Liganden la-d sind so schwach und hart, daB bei den Co3+-Komplexen 3a-d ein Gleichgewicht zwischen der d6-,,high spin"-und ,,low spin"-Elektronenkonfiguration existiert. Die Lage dieses Gleichgewichtes 118t sich uber den sterischen Anspruch der Alkoxy-Substituenten in weiten Grenzen steuern. Die Ethyl-Substituenten machen dagegen l e aus elektronischen Grunden zu einem deutlich starkeren Liganden als la-d. Der Co3+-Komplex 3e liegt ausschliel3lich in der diamagnetischen ,,low spin"-Konfiguration vor. ERA 477, Univenite de Rennes F-35 042 Rennes Cedex (Frankreich) P. Michaud Groupe dc Physique et Chimie du Solide, ERA 682 F-72017 Le Mans Cedex (Frankreich) [**I Wir danken Drs. J:R. Hamon. C. Lapinte und J.-M. Basset fiir Diskussionsbeitrige sowie Dr. J.-P. Mariot und Prof. F. Varret fur Hilfe bei den MaObauer-Untenuchungen. Diese Arbeit wurde vom CNRS (ATP 9812) und vom DGRST (Stipendium fiir P. M.) unterstiitzt. Angew. Chem. 94 (1982) Nr. 12 0 Verlag Chemie GmbH. 0-6940 Weinheim. 1982 0044-8249/82/1212-0921 S 02.50/0
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