The direct reaction between 6-mercaptopurine (6-MP) and Cd(II) under different conditions yields either [Cd2(6-MP)4(NO3)2](NO3)2 (1) or [Cd(6-MP-)2.2H2O]n (4). Compound 1 behaves as the building block of the polymer [Cd(6-MP2-)2]n[Ca(H2O)6]n (3), by deprotonation of 6-MP ligand. In the reaction of 1 to give 3, the dinuclear compound [Cd2(6-MP)4(H2O)2](NO3)4.2H2O (2) can be isolated as an intermediate. Polymers 3 and 4 convert into each other in water via deprotonation-protonation reactions. The structures of compounds 1-3 have been determined by X-ray diffraction. Given the small differences in the arrangement shown in the crystal structures of the polymer 4 and the polyanion of 3, the stabilities and energetics of the two arrangements have been examined by DFT calculations to determine the possibility of identifying new conformations of both polymers. In addition, the two polymers have been characterized on surfaces by means of AFM. The direct reaction between 6-MP and Cd(II) and the deprotonation of the polymer 4 have proven to be useful routes for the isolation of one-dimensional systems on surfaces. The development of new strategies to characterize these types of polymers on surfaces opens the possibility to perform nanoscale studies on their properties and their potential use as nanomaterials.

Calculations performed with the goal of designing suitable electrical conductive [M(6-MP)(2)](n) (M = transition metal, 6-MP = 6-mercaptopurinato) one-dimensional coordination polymers suggested that metal ions such as Ni(II) could provide suitable materials. In this work, direct hydrothermal reactions between 6-mercaptopurine (6-MPH) and the analogous 6-thioguanine (6-ThioGH) with NiSO(4).6H(2)O yield the compounds [Ni(6-MP)(2)](n).2nH(2)O [1] and [Ni(6-ThioG)(2)](n).2nH(2)O [2]. The X-ray structures confirm that both compounds present similar structures based on one-dimensional chains in which the deprotonated nucleobases act as the bridging ligands connecting the metal ions by short distances. Electrical measurements at room temperature confirm the conductor character of both coordination polymers. The small differences found in these measurements have been rationalized with the help of density functional theory calculations. Preliminary adsorption studies on surfaces for 1 have allowed characterization of single chains on mica and graphite. The results obtained suggest the potential use of coordination polymers on nanomaterials for molecular electronics.

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