Ag(i) complexes with alkylidene-bis(2-aminopyrimidines) as building units for discrete metallomacrocyclic frames. A structural and solution study

Abstract

Alkylidene-bis(2-aminopyrimidines) (pyr₂C_x, x = 2–5) are useful ligands to interact with Ag(I) yielding discrete metallocycles. Crystal structures of the [(pyr₂C₂)Ag(NO₃)]₂ and [(H-pyr₂C₄)Ag(NO₃)₂]₂ have been isolated where each macrocyclic moiety interacts with their surroundings through weak interactions, yielding 3D discrete structures, On the other hand, the solution study shows that the equilibrium constants for the formation of Ag(pyr₂C_x)⁺ complexes are higher than the literature values for Ag(I) complexes with single pyrimidines, although the differences could be explained by invoking the solid-state structures of the Ag(I)–pyr₂C_x complexes.