Two 2D silver(I) coordination polymers derived from mixed ligands: Syntheses, structures, photoluminescent and thermal properties

Two isomers of the aminobenzonitrile were reacted with Ag2O and phthalic acid under ultrasonic condition, yielding two coordination polymers (CPs) of the formula [Ag2(o-abn)(pa)]n (1) and [Ag4(m-abn)(pa)2]n (2). They have been characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Both complexes 1 and 2 are 2D sheet structures which contain two different Ag(I) aggregates, 1D silver helical chain and 2D silver sheet for 1 and 2, respectively. The o-abn in 1 adopts a rare tridentate μ3-N,N′N′ mode to bridge the neighboring 1D silver chains to form a 2D coordination network, while the m-abn ligand just acts as a monodentate N-donor in 2 and does not contribute to the extension of the 2D silver sheet to the higher dimensionality. As the change of the relative position of amino and cyano groups of the aminobenzonitrile ligand, the dimensionality of the Ag(I) aggregates in 1 and 2 increases from 1D to 2D, which indicates that the relative positions of amino and cyano groups of aminobenzonitrile play an important role in the formation of the diverse Ag(I) aggregates, as a consequence, different 2D coordination networks are produced. Additionally, results about emissive behaviors and thermal stabilities of them are discussed.