Effect of different reaction conditions on the structural diversity of zinc(II) complexes with 9-deazahypoxanthine

The reactions of ZnX·nH2O (X = 2Cl− or SO42−) with 9-deazahypoxanthine (3,5-dihydro-4H-pyrrolo[3,2-d]pyrimidin-4-one, 9dhx), depending on the reactants, reaction medium and molar ratios between the reactants, afforded (9dhxH)2[ZnCl4]·H2O (1), [Zn(9dhx)Cl2]n (2) and [{Zn(9dhx)(H2O)3}2(μ-SO4)2] (3). The compounds were characterized by elemental analysis, infrared and multinuclear NMR spectroscopy, mass spectrometry, and single crystal X-ray analysis. X-ray analysis revealed that the complexes display different types of structures in terms of covalent bonds, i.e. zero-dimensional (0D) (1), 1D polymeric (2) and dimeric (3). Crystal structures of the complexes are stabilized by extended networks of N–H⋯Cl, O–H⋯Cl, O–H⋯O hydrogen bonds and π–π non-covalent contacts. The structural diversity of these compounds shows the coordination behavior of 9-deazahypoxanthine and also points out the coordination versatility of this heterocyclic compound. Moreover, in vitro cytotoxicity of complexes 1 and 3 were evaluated on human malignant melanoma (G361) and prostate epithelial (22Rv1) cancer cell lines.

Three zinc(II) complexes (9dhxH)2[ZnCl4]·H2O (1), [Zn(9dhx)Cl2]n (2) and [{Zn(9dhx)(H2O)3}2(μ-SO4)2] (3) involving 9-deazahypoxanthine (9dhx) were synthesized and thoroughly characterized by various methods including single crystal X-ray analysis, and tested for their in vitro cytotoxicity against G361 and 22Rv1.Figure optionsDownload as PowerPoint slide