Bergs, Ralph; Sünkel, Karlheinz; Beck, Wolfgang (1993): Metallkomplexe mit biologisch wichtigen Liganden, LXVIII. Metallorganische Asparaginato-Cobaltkomplexe als Liganden für Alkali-Ionen. In: Chemische Berichte, Vol. 126, Nr. 11: S. 2429-2432




The trischelate complexes of the dianion of aspartic acid and -methylaspartic acid (5-C5Me5) (R = H, Me) form adducts with alkali iodides MI (M = Li, Na, K). The polymeric structure of (5-C5Me5)Co(L-asp.-2H+)KI (1c) was determined by X-ray diffraction. In the crystal of 1c the potassium ions are surrounded by five oxygen atoms of the carboxylate groups whereby two oxygen atoms form bridges between two K+ ions. Similarly, trischelate complexes 4 and 5 have been obtained from (5-C5Me5)Co(CO)I2 and 2,3-diaminopropionic, 2,4-diaminobutyric acid, and asparagine, respectively.