Solution-State Studies, X-ray Structure Determination and Luminescence Properties of an Ag(I) Heteroleptic Complex Containing 2,9-Bis(styryl)-1,10-phenanthroline Derivative and Triphenylphosphine

Abstract

A novel heteroleptic Ag(I) compound, formulated as [AgL(PPh3)]BF4 (1) (where L represents 2,9-bis((E)-4-methoxystyryl)-1,10-phenanthroline and PPh3 stands for triphenylphosphine), was successfully synthesized and thoroughly characterized. The compound’s stability in solution was confirmed through 1D and 2D nuclear magnetic resonance (NMR). The photo-irradiation of the complex in a CDCl3 solution, utilizing a common portable UV lamp emitting at λ = 365 nm, led to the partial transformation of the E,E-geometric isomer to E,Z, ultimately yielding a 1:1.4 molar ratio of isomers. Its molecular structure was determined via X-ray crystallography, while molecular packing was assessed using Hirshfeld calculations. The most notable interactions (51%) within the cationic inner sphere involved H···H bonds. The photophysical characteristics of the complex and L were evaluated both in the solid state and in solution (dichloromethane). Compound 1 is a weak emitter, with photoluminescence quantum yields of 8.6% and 4.3% in solution and the solid state, respectively.

Keywords

• Ag(I) coordination complex
• X-ray
• Hirshfeld analysis
• photoluminescence
• NMR studies
• photo-isomerization