Anion influence on structure and photoluminescence properties of silver(I) complexes with naphthalene-2,3-diyl-diisonicotinate

The anion effects on the formation and photoluminescence (PL) of a series of AgX (X− = NO2−, NO3−, ClO4−, and PF6−) compounds with naphthalene-2,3-diyl-diisonicotinate (L) were investigated. According to the single-crystal X-ray structures, the NO2−, NO3−, and ClO4− anions act as anionic ligands rather than as simple counteranions whereas the PF6− anion acts as a simple counteranion. Correspondingly, the dinitroargentate anionic species, Ag(NO2)2−, was observed in the solid state. The PL intensity of the present compounds, moreover, was proportional to the Ag⋯X distance, namely the metallophilicity of the anions. The weak- or non-coordinating anions, ClO4− and PF6−, could be smoothly exchanged with the NO2− or NO3− anion, whereas the reverse exchanges did not occur. The compounds’ physicochemical properties were characterized by means of infrared (IR) spectroscopy, thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC), and PL.