Up to eight redox-active ferrocenyl units have been incorporated, through the unsaturated ethynyl linkers, on the periphery of a series of cyclic tetrapyrrole derivatives including zinc(II) phthalocyanine and 2,3-naphthalocyanine, and nickel(II) meso-diphenylporphyrin. The synthesis of the former two macrocycles 4 and 7 involves the Sonogashira coupling reaction of ferrocenylethyne with 4,5-dichlorophthalonitrile (1) or 6,7-dibromonaphthalonitrile (5), respectively, followed by a base-promoted cyclization. The meso-bis(ferrocenylethynyl)porphyrin 11 has been prepared from the dibromo analogue 10 also by a palladium-catalyzed coupling reaction. These novel macrocyclic compounds have been spectroscopically and electrochemically characterized. As revealed by cyclic voltammetry, the ferrocenyl moieties appear to be electrochemically independent in these complexes and there is no significant electronic coupling among the iron(II) centers.
Elementary form of nitrogen (protein), phosphorus, potassium and magnesium contained in sixty-six different kinds of Chinese medicines were analyzed by means of 14-MeV neutron activation technique. The % contents of these elements in Chinese medicines range from 4.1 to 38.6% (average: 12.7%) for protein, 0.1 to 10.5% (average: 1.3%) for phosphorous, 1.6 to 13.8% (average: 4.5%) for potassium and 0.1 to 2.5% (average: 0.5%) for magnesium. The procedure proves to be quite precise and potentially quite accurate, while only requiring about 20 minutes per sample. The methods of determining the elements are described.
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