Two 2D sliver complexes with a symmetric and noncentrosymmetric architecture controlled by the metal–ligand ratio

Abstract

The hydrothermal reaction of silver nitrate and 2,2′-phosphinico-dibenzoic acid (H₃L) with different metal to ligand ratios under hydrothermal conditions yielded two unusual complexes with the formulae of [Ag(H₂L)]_n (1) and [Ag₃(L)]_n (2). Both complexes were well characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopic and fluorescence studies. Complex 1 crystallizes in a centrosymmetric Pbcn space group and presents a two-dimensional (2D) layer structure through silver(I)-aromatic interaction, whereas complex 2 adopts a noncentrosymmetric Iba2 space group, in which the different coordination modes of the four groups around the phosphorus atom in the L³⁻ ligand occurs. Both complexes display green emissions, assigned as the ligand-to-metal charge-transfer character.