Tunable White Light Emission of a Metal-Organic Framework Based on a Bisquinoxaline Derivative by Introducing Red-Green Cationic Dyes.

The unique structural advantages give metal-organic frameworks (MOFs) a special use as host substrates to encapsulate organic dyes, which would result in specific host-guest composites for white-light phosphors. In this work, an anionic MOF exhibiting blue emission was constructed using bisquinoxaline derivatives as photoactive centers, which could effectively encapsulate rhodamine B (Rh B) and acriflavine (AF) to form an In-MOF ⊃ Rh B/AF composite. By simply adjusting the amount of Rh B and AF, the emitting color of the resulting composite could be easily adjusted. The formed In-MOF ⊃ Rh B/AF composite exhibits broadband white light emission with ideal Commission International ed'Eclairage (CIE) coordinates of (0.34, 0.35), a color rendering index of 80.8, and a moderately correlated color temperature value of 5193.96 K. This strategy can be easily extended to other blue-emitting MOFs and dyes, thus opening up new prospects for the development of white-light-emitting materials.