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)3 in 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 CuCl2 in 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.