A near-infrared emitting MOF: controlled encapsulation of a fluorescein sensitizer at the time of crystal growth.

We report here a near-infrared (NIR) emitting lanthanide-based metal–organic framework (MOF) in which Yb3+ are sensitized by fluorescein (FL) as a low energy absorbing chromophore (FL@CD-MOF-161). The unique design of CD-MOF-161 allows for the entrapment of FL molecules in its pores during the synthesis and crystal growth, ensuring the efficient loading and spreading of chromophores within the crystal volume. [ABSTRACT FROM AUTHOR]