Luminescence of a Ruthenium Complex Monolayer, Covalently Assembled on Silica Substrates, upon CO Exposure

High quality silica and Si(100) substrates were functionalized with a covalent 4-ClCH2C6H4SiCl3 monolayer. Additional covalent bonding of an OH-phenol functionalized asymmetric ruthenium complex [Ru(bpy)2L](PF6)2 to the silylated substrates was further achieved, thus fabricating a new monolayer of ruthenium complex molecules on both silica and Si substrates. The chemical and spectroscopic characterization was carried out by X-ray photoelectron and UV−visible spectroscopy measurements. The optical properties of this robust monolayer were studied at room temperature by luminescence measurements in controlled atmosphere. Results grant the system recognition properties for CO at ppm levels. The adopted synthetic procedure has proven to be effective in transferring molecular properties to the solid state thus obtaining a photoluminescent device.