Purines zinc complexes

Mononuclear complex formation was confirmed for the adduct of zinc(II) salt with 2-mercaptobenzothiazole and o-phenanthroline (253). The t/-S coordination is observed in the complexes of triphenylphos-phine gold with 2-mercapto-l-methylimidazole (254) (88JOM119), 8-mercaptotheophilline (255) (91IC3743), 2-mercaptobenzoxazole (256) [94AX(C)1420], and purine-6-thiol (257) (94AJC577). 

The complex [(HLJZnCUJ (L = purine) has been shown to possess the tetrahedral structure (80) (Zn—Cl, 2.226-2.254 A Zn—N, 2.054 A).548 The interaction of 7-azaindole (81) with zinc chloride has been investigated, and the products [Znl CU] (Zn—Cl, 2.231, 2.212 A Zn—N, 2.063, 2.038 A) and [LH]2[ZnCU] have been structurally characterized.548 Complexes of zinc with cytosine,549 adenosine triphosphate550-552 and other purines553 have been investigated, and a crystal structure of the complex [ Zn(bipy)(H2ATP) 2] 4H2O551 has been described. 

Sigel, H. and Naumartn, C. F., Ternary complexes in solution. XXIV. Metal ion bridging of stacked purine-indole adducts. The mixed-ligand complexes of adenosine 5 -triphosphate, tryptophan, and manganese(II), copper(II), or zinc(II), /. Am. Chem. Soc., 98(3], 730, 1976. 

The indirect determination of certain organic substances can be made by complexometric titration methods. Such methods depend on the formation of an insoluble product between the organic material and a metal then, either the excess metal in solution is determined by a suitable titration with EDTA, or the metal-containing precipitate is decomposed and the liberated metal ions titrated. Thus, for example, narcotine, papaverine, codeine, strychnine and brucine have been determined by formation of iodobis-muthate complexes, chlorpromazine and quinine" as cadmium iodide complexes, purines and nicotinic acid derivatives by precipitation with mercury and barbiturates by precipitation with zinc. ... 

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