Unusual Colorimetric Change for Alkane Solvents with a Porous Coordination Framework

Alkane-selective colorimetric change from white to pink was observed with the simple system consisting of UiO-66 and 7-azaindole. The colorimetric change was strongly enhanced with increasing amounts of defects inside the UiO-66 framework, which indicates that interaction between the defects and 7-azaindole plays a pivotal role for this phenomenon.