Syntheses, characterizations, thermal stability and photoluminescence of four silver coordination polymers with mixed ligands

Four silver(I) coordination polymers (CPs), namely, [Ag2(mpyz)(ipa)]n (1) [Ag3(mpyz)(btc)]n (2) [Ag4(apyz)2(ipa)·0.5 DMF]n (3) [Ag3(apyz)2(btc)]n (4), have been purposefully synthesized under ultrasonic treatment of methylpyrazine (mpyz), aminopyrazine (apyz), isophthalic acid (H2ipa), 1,3,5-benzenetricarboxylic acid (H3btc) and AgNO3. And they were characterized by elemental analysis and X-ray single-crystal diffraction. Complexes 1 and 2 based on the same auxiliary ligand mpyz show various structures with silver chain. Complex 1 features a three-dimensional (3D) structure which consists of 1D helical silver chains. Complex 2 possesses an infinite silver chain with repeated Ag-triangle units. Complexes 3 and 4 with apyz as auxiliary ligand exhibit different structures. Complex 3 exhibits a 2D 44-sql network with the 1D double chains and complex 4 shows Ag6 units which are connected by Ag⋯Ag interaction in the 3D coordination network. Effects of the aromatic polycarboxylates on the structures and the intricacy of the self-assembly process were discussed. Additionally, results about infrared spectroscopy (IR), thermogravimetric analyses (TGA) and photoluminescence spectra behaviours of the compounds were also discussed.