Lanthanide-based near-infrared emitting metal-organic frameworks with tunable excitation wavelengths and high quantum yields.

We report here two isoreticular ytterbium (Yb) 2D metal-organic frameworks (MOFs) emitting near-infrared (NIR) luminescence with 1.26(2)% quantum yield values, which are among the highest values reported to date for MOFs incorporating NIR-emitting lanthanide cations. The excitation wavelength of the YbIII MOFs can be red-shifted to the visible range by introducing an amino group to the organic chromophore. Density functional theory (DFT) calculations were performed to gain insights into the photophysical properties of this new family of MOFs.