3α, 17α, 21-Trihydroxy-5α-pregnan-20-on und Subst. TR 1018. Über Bestandteile der Nebennierenrinde und verwandte Stoffe, 101. Mitteilung

✍ Scribed by J. v. Euw; R. Neher; T. Reichstein

• Publisher: John Wiley and Sons
• Year: 1962
• Tongue: German
• Weight: 559 KB
• Volume: 45
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19620450128

✦ Synopsis

The authors investigate the reaction products formed, when Fe(H,O),,+ is deprotonated in perchlorat? solutions. When a small amount of base is added, metastable solutions containing the ions Fe(H,O),+, Fe(H,0)50H2+, Fe,(H,0),(OH)4+ and Fe(H,O),(OH)+ are formed, and a-FeOOH slowly crystallises out. In a narrow intermediate range immediately after adding the base, colloidal amorphous Fe(OH), and crystalline u-FeOOH are formed. If more base is added a dark brown solution of colloidal amorphous Fe(OH), results, in which the crystallisation of a-FeOOH, under certain conditions also of y-FeOOH, begins after an induction period of several days. Only when a nearly equivalent amount of base is added, Fe(OH), is precipitated. On ageing, this changes partly into a-Fe,O,, partly into u-FeOOH, a rather large amount remaining amorphous. In all the systems, no stable state is reached at room temperature, even after years. If a small amount of Fe2+ ions is coprecipitated, a complete crystallisation of the amorphous hydroxide to a-FeOOH takes place. The mechanism of the formation of the crystalline phases is discussed.