Guanine cadmium complexes

A number of zinc and cadmium complexes of adenine (82),554,555 adenine N-oxide,556 guanine,557 inosine,558 cytidine559 and other nucleosides560 have been studied. The structure of (9-methyladenine)ZnCl2 is polymeric each zinc ion is tetrahedrally coordinated to two chlorine atoms (Zn—Cl = 2.22 A), and to N-l and N-7 of neighbouring adenine moieties (Zn— N = 2.05A).561 A structural study of the related cadmium complex, CdCl2(DMSO)L (L = 9-methyladenine), has shown the complex to form a one-dimensional polymer. 2... 

A structure determination of CdL(H20)5 3H20 (L = guanosine-5 -phosphate) reveals a cadmium ion octahedrally coordinated by live water molecules and the N-7 of the purine ring system (Cd—N = 2.37 A Cd—O = 2.24-2.34 A).568 Similarly, a structure determination of CdL2(H20)4 (L = 8-azahypoxanthinato) reveals octahedral cadmium bonded to N-7 of the purine anions and to four water molecules.569 Theophylline (83) is frequently used as a substitute for guanine (84) in model systems, and the complexes [CdI (RNH2)2(H20)2] (L = 83) have been described.570... 

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