Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

The inorganicpigmentsmalachite,Egyptianblue,Ercolanoblueandchromeyellowhavebeendoped with theneutralhomolepticLn(III)complexLn(Tp)3 (Ln1⁄4Eu, Tb;Tp1⁄4hydrotris(pyrazol-1-yl)borate)in the presenceofarabicgumoracrylicemulsionasbinders,inordertoobtainphotoluminescentmaterials of interestforculturalheritagerestoration.Thedopedpigmentshaveshownemissionsassociatedtof–f transitions inthevisiblerangeuponexcitationwithUVlight.ThermalandUV-lightageingshavebeen carried out.Inallthecasesthephotoluminescentbehaviourismaintained,butinthecasesofacrylic- based paintsemissionspectraandlifetimesarestronglyinfluenced bythermaltreatments.Thechoiceof binder andpigmentsinfluences thephotoluminescentbehaviourofthecorresponding film paints.