A photoactive {Ti16} metal–organic coordination capsule with a cavity length of ∼1.4 nm was synthesized and structurally characterized by single-crystal X-ray diffraction analysis. This {Ti16} coordination capsule has a much enhanced visible-light absorption band with a narrow band gap of 2.1 eV. In this highly porous crystalline coordination capsule, 2,5-dihydroxybenzoate (DHB) photosensitizers and Ti-oxo cluster units can work cooperatively to promote the photoelectrochemical and photocatalytic performance.
