Multi-uracil arrays built on organostannoxane, organotelluroxane, and copper(II) carboxylate platforms. C-H⋯O interactions leading to tetrameric uracil motifs

The reaction of 3-(N1-uracyl)propanoic acid (LH) with (t-Bu₂SnO)₃in a 3:1 ratio afforded the hydroxide-bridged dimer [t-Bu₂Sn(μ-OH)L]₂(1). A similar reaction involving bis(tri-n-butyltin)oxide, (n-Bu₃Sn)₂O, in a 2:1 ratio afforded the one-dimensional (1D) coordination polymer [(n-Bu₃SnL)]_n(2). Similarly, the reaction of LH with (MeOAr)₂TeO in a 2:1 ratio afforded the mononuclear [(MeOAr)₂TeL₂]·H₂O (3). On the other hand, a similar reaction in a 1:1 ratio gave the dinuclear product [{(MeOAr)₂TeL}₂O]·C₂H₅OH·CH₃OH·H₂O (4). The reaction of complex 1 with CuCl₂in a 1:1 ratio yielded [Cu(II)L₂H₂O]₂·6H₂O (5). All the complexes show an extensive supramolecular organization in the solid state as a result of several intermolecular interactions. The role of uracil substituents in determining the final course of the supramolecular assembly is discussed. A tetrameric uracil supramolecular motif is formed in the crystal structure of complex 1 as a result of C-H⋯O interactions. Uracil-water interactions involving only C-H⋯O interactions have been observed in complex 5.