Phenol-Driven Modulation for the Synthesis of a Plant-based Titanium Metal-Organic Framework

Titanium-based metal-organic frameworks (MOFs) stand out owing to their hydrolytic stability and promising photocatalytic properties. However, the high reactivity of titanium precursors has limited their discovery to a comparably small number of structures reported to date. Strongly coordinating chelate linkers, such as ellagic acid (EA), amplify the synthetic difficulty of controlled crystal growth. To tackle this challenge, we employed an untapped modulator in MOF chemistry – phenol – which enabled the isolation of a new Ti-based MOF. TUW-11 (TUW = TU Wien) is built up of monometallic Ti4+ centers strongly bound by EA, resulting in a layered, honeycomb-like microporous framework. The underlying structure was determined by three-dimensional electron diffraction (3D ED), together with synchrotron X-ray techniques and scanning transmission electron microscopy. Furthermore, optoelectronic properties were studied thoroughly, and promising performance towards light-assisted dye removal reactions could be demonstrated using visible light.