Molecular recognition patterns of 2-aminopurine versus adenine: A view through ternary copper(II) complexes

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• 作者：Alicia Dom&#xed ; nguez-Mart&#xed ; n^a ; ^{adominguez@ugr.es"" rel=""nofollow} ; Duane Choquesillo-Lazarte^b ; Josefa Mar&#xed ; a Gonz&#xe1 ; lez-P&#xe9 ; rez^a ; Alfonso Castiñ ; eiras^c ; Juan Nicló ; s-Guti&#xe9 ; rrez^a
• 关键词：Molecular recognition ; Mixed-ligand copper(II) complexes ; 2-aminopurine ; Iminodiacetate ; Metal binding pattern ; Interligand interactions
• 刊名：Journal of Inorganic Biochemistry
• 出版年：2011
• 出版时间：August 2011
• 年：2011
• 卷：105
• 期：8
• 页码：1073-1080
• 全文大小：1256 K

文摘

In contrast to the comprehensive structural information about metal complexes with adenine, the corresponding to its isomer 2-aminopurine (H2AP) is extremely poor. With the aim to rationalize the metal binding pattern of H2AP, we report the molecular and/or crystal structure of four novel compounds with various iminodiacetate-like (IDA-like) copper(II) chelates: [Cu(IDA)(H2AP)(H2O)]·H2O (1), [Cu(MIDA)(H2AP)(H2O)]·3H2O (2), {[Cu(NBzIDA)(H2AP)]·1.5H2O}n (3) and [Cu(MEBIDA)(H2AP)(H2O)]·3.5 H2O (4), where IDA, MIDA, NBzIDA and MEBIDA are R = H, CH3, benzyl- and p-tolyl- in R-N-(CH2-COO-)2 ligands, respectively. Synthesis strategies include direct reactions of copper(II) chelates with H2AP (alone, for 1 and 3) and/or with the base pairs H2AP:thymine (1–4) or H2AP:cytosine (3). Moreover, these compounds have been also investigated by spectral and thermal methods. Regardless of the N-derivative of the IDA chelator, molecular recognition between H2AP and the referred Cu(II)-chelates only displays the formation of the Cu–N7(purine-like) bond what is clearly in contrast to what was previously reported for adenine. The metal binding pattern of 2-aminopurine is discussed on the basis of the electronic effects and steric hindrance of the 2-amino exocyclic group.