Syntheses, structures and photoluminescent properties of a series of Ag(i) coordination architectures based on 2,4-diamino-6-methyl-1,3,5-triazine and dicarboxylates: from a 0D discrete molecule to a 3D infinite network

Abstract

Five mixed-ligand Ag(I) coordination complexes (CCs), namely, [Ag2(dmt)2(suc)·H2O]n (1), [Ag2(dmt)2(suc)(H2O)·0.5H2O] (2), [Ag2(dmt)2(glu)]n (3), [Ag2(dmt)2(adip)]n (4), and [Ag2(dmt)2(tpa)]n (5) (dmt = 2,4-diamino-6-methyl-1,3,5-triazine, H2suc = succinic acid, H2glu = glutaric acid, H2adip = adipic acid, H2tpa = terephthalic acid), have been synthesized through a one-pot ultrasonic reaction of AgNO3, dmt and different dicarboxylates and characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. Complexes 1 and 2 formed in different solvent systems (methanol/acetonitrile for 1 and methanol/ethanol for 2) exhibit a two-dimensional (2D) sheet and a zero-dimensional (0D) tetranuclear motif, respectively. Different solvent systems influence the coordination modes (μ2-N,N′ for 1 and μ1-N for 2) of dmt and the conformations (anti for 1 and gauche for 2) of the suc anion; as a result, two diverse structures are produced. Complex 3 is a one-dimensional (1D) chain structure running along the a axis constructed from the [Ag2(μ1-dmt)2] subunit and the gauche–gauche μ5-η1:η1:η1:η2 glu ligand. Similarly, complex 4 is also a 1D chain structure, but the adip ligand adopts an anti–anti–anti conformation to link the [Ag2(μ1-dmt)2] subunit to complete the 1D chain. Complex 5 is a complicated 3D framework built from a tetrahedral Ag(I) center, a quadridentate tpa and an angular bidentate dmt ligand which can be simplified as a new (2,4,4)-connected 3-nodal net with the Schlafli symbol of {4.84.12}2{42.82.102}{8}2. The results show that the dicarboxylate and the solvent system play crucial roles in the formation of the resulting structures. Additionally, results about thermogravimetric curves and photoluminescence spectra were discussed.