Structural diversity in the (Ag–NO3-–2-aminopyrimidyl derivatives) system: New zero-, one-, and two-dimensional inorganic–organic hybrids

Five new silver(I) complexes of the formula [Ag(L1)(NO3)]n (1), [Ag4(L2)6(NO3)4] (2), [Ag(L3)(NO3)]n (3), [Ag3(L4)3(NO3)3]n (4), and [Ag(L4)(NO3)]n (5) have been synthesized by reactions of silver(Ι) nitrate with a family of 2-aminopyrimidine and its derivatives (namely, 2-aminopyrimidine (L1), 2-amino-4,6-dimethylpyrimidine (L2), 2-amino-4-methoxy-6-methylpyrimidine (L3), and 2-amino-4,6-dimethoxypyrimidine (L4), respectively). The influences of substituted groups of ligands and reaction solvent systems on the structure of the complexes are discussed. The reaction of AgNO3 with L1 yields a one-dimensional (1-D) zigzag chain (1). The reaction of AgNO3 with L2 leads to a zero-dimensional (0-D) tetramer (2). When L3 is used, a two-dimensional (2-D) grid network (3) is obtained. On the other hand, by using the same silver(Ι) nitrate but different reaction solvent systems, 4 and 5 are isolated, respectively. Complex 4 has a 1-D polymeric ribbon further connected by intermolecular hydrogen bonds to form a 2-D layer structure. While 5 shows a 2-D honeycomb-like layer consisting of 24-membered metallocycles. The results reveal that the nature of organic ligands and the choice of solvent all have great impact on the structure of the complexes. In addition, the secondary forces such as hydrogen-bonding interactions including intramolecular and intermolecular hydrogen bonds also play important roles in the formation of supramolecular architectures, for instance, to link low-dimensional entities to high-dimensional frameworks. The luminescence properties of the synthesized silver complexes were investigated in the solid state at room temperature.

Graphical abstractFive new luminescent silver(Ι) complexes have been prepared by reactions of silver(Ι) nitrate with a family of 2-aminopyrimidine and its derivatives and characterized by X-ray single-crystal diffraction. The results reveal that the substituted groups of ligands and reaction solvent systems have great influence on the formation and structure of metal–organic frameworks. In addition, the secondary forces such as hydrogen bonds also play important role in the overall architecture and stabilization of the complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide