Tunable colors and white-light emissions by encapsulation of guest molecules or ions into a flexible metal–organic framework

Abstract Metal-organic frameworks (MOFs) are well known for their tunable structure and porosity with various important applications. In particular, their performance can be further improved by encapsulating luminescent guest molecules or lanthanide ions. This work aims to develop tunable colors and white-light emission materials by encapsulation of organic molecules and Eu3+ (or Tb3+) ions within a porous MOF (USTC-1). Various guest organic molecules or lanthanide ions are encapsulated into this MOF, yielding blue, blue-green, green, pink and red phosphorescence, respectively. Significantly, white-light emission can be achieved by encapsulating yellow- or green/red-emitting guest organic molecule into blue-emissive USTC-1 and adjusting the content of guest organic molecules. In addition, the white-light emissive USTC-1 composite materials can also be easily achieved by variation of the inclusion amount of single Eu3+ or Tb3+ ion in the host framework of USTC-1. The present work firstly reported white-light MOF-based composite materials by encapsulation of single organic molecule (non-dye molecule), and such strategy may open new perspectives for developing novel white-light emission materials by encapsulation of organic molecules or lanthanide ions.