Supramolecular Signatures of Adenine-Containing Organostannoxane Assemblies

The reactions of 3-(N9-adeninyl) propanoic add (LH) with various di- and triorganotin oxides have been investigated. Thus, the reaction of di-tert-butyltin oxide (t-Bu2SnO)(3) in a 3:1 ratio afforded the dinudear derivative [t-Bu2Sn(J4-0H)L](2)center dot 7H(2)0 (1). A similar reaction involving bis(tri-n-butyltin)oxide, (n-Bu3Sn)(2)O, in a 2:1 ratio afforded the one-dimensional (1D) coordination polymer [n-Bu3SnL center dot 0.33H(2)O], (2). Similarly the reaction with (n-Bu2SnO)(n) in a 2:1 ratio afforded the tetranuclear an-Bu(2)SnI2(mu(3)-0)(p-OH)L](2) (3). On the other hand, a similar reaction in a 1:1 ratio also gave the tetranuclear product [{an-Bu2Sn}(2)(mu(3)center dot 0)L](2) (4). The molecular structure of 1 reveals a central dinudear Sn202 motif where the two tin centers are bridged by two p-OH groups. Each tin is bound with a monodentate carboxylate group; the C=0 unit of these carboxylates is involved in an intramolecular hydrogen bonding with the bridging OH unit The supramolecular structure of 1 reveals the formation of a ID zigzag chain mediated by intermolecular hydrogen bonding interaction through the Watson-Crick or the Hoogsteen faces. 2 is a ID coordination polymer formed by the successive bridging of triorganotin units by the carboxylate ligand L The supramolecular structure of 2 reveals that two 1D coordination polymers interact to generate novel adenine homotrimers formed as a result of alternating Watson-Crick Watson-Crick and Hoogsteen Watson-Crick interactions. The molecular structures of 3 and 4 reveal them to be tetranuclear possessing a ladder-like structure. The essential difference between their molecular structures is that in 4 there are four carboxylate ligands, while in 3 there are only two. Both of these complexes reveal intramolecular and intermolecular hydrogen bonding and n...n stacking interactions. The nematicidal activity of 1-3 was examined against Caenorhabditis elegans. Compound 2 was found to be highly active, effecting a high mortality even at very low concentrations such as 25 or 10 ppm.