The 2D isostructural lanthanide-organic frameworks [Ln(4-SBA)(IP)OH] · 1.5H2O (Ln = Sm 1, Eu, 2 Gd3 and Tb 4 ; 4-SBA = 4-sulfobenzoate and IP = 1H-imidazo[4,5-f][1,10]-phenanthroline) display different luminescent behavior. White light emission was realized by introducing single dopant Eu(III) and codopants Eu(III)/Gd(III) or Eu(III)/Tb(III) into the Sm(III) framework for the first time.