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

Abstract

The reaction of L1H {L1H = 3-(N9-guaninyl)propionic acid} with Me₃SnCl or (n-Bu₃Sn)₂O 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)₂O in a 2 : 1 ratio afforded a dimer [(n-Bu₃SnL3)₂·H₂O] (4). A mononuclear compound [Me₃Sn(L4)·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 (GG), between inter-chain guanine units has been observed. Similarly a homo orotatequartet has been observed in 4 as a result of intermolecular interactions.