Amide-bridged Eu(III) coordination polymer for stable luminescent glass material

Abstract

A novel lanthanide coordination polymer composed of Eu(III) ion, low-vibrational frequency hfa (hfa: hexafluoroacetylacetonato), and phosphine oxide ligand with amide groups (dpba: N,N'-(ethane-1,2-diyl)bis(4-(diphenylphosphoryl)benzamide)), Eu-dpba is reported. A lanthanide coordination polymer with alkyl groups (dph: 1,6-bis(diphenylphosphoryl)hexane), Eu-dph is also prepared, as a reference sample. Eu-dpba showed phase transition behavior at 128 °C, although alkyl-bridged Eu-dph showed no phase transition behavior by differential scanning calorimeter measurements. The smooth surface on the Eu-dpba after heat treatment was observed using scanning electron microscope. The photophysical properties were estimated using the emission spectra and the emission lifetimes. We found that the emission quantum yield of Eu-dpba with heat treatment is the same as that of Eu-dpba without heat treatment.