Organostannoxane-supported nucleobase arrays: synthesis and supramolecular structures of polymeric and molecular organotin complexes containing guanine, uracil and 2-aminopurine

The reaction of L1H {L1H = 3-(N9-guaninyl)propionic acid} with Me3SnCl or (n-Bu3Sn)(2)O afforded the 1D coordination polymers, [Me3Sn(L1)](n) (1) and [n-Bu3Sn(L1)](n) (2) respectively. A reaction between L2H {L2H = 3-(N7-guaninyl)propionic acid} with Me3SnCl also afforded a 1D coordination polymer, [Me3Sn(L2)](n) (3). A similar reaction between L3H [uracil-6-carboxylic acid] with (Ph3Sn)(2)O in a 2 : 1 ratio afforded a dimer [(n-Bu(3)SnL3)(2)center dot H2O] (4). A mononuclear compound [Me3Sn(L4)center dot H2O] (5) was obtained in a 1 : 1 reaction of 3-{N9-(2-aminopurinyl)}propanoic acid (L4H) with Me3SnCl. Complexes 1-5 show rich supramolecular structures in the solid state as a result of several intermolecular interactions. Thus, in the one-dimensional coordination polymer 3, triple hydrogen bonding (G equivalent to G), between inter-chain guanine units has been observed. Similarly a homo orotatequartet has been observed in 4 as a result of intermolecular interactions.