Syntheses, Crystal Structure, and Photochromic Properties of a New Stable Ti (Ⅳ) Complex

Abstract

A novel photochromism of titanium complex, formulated as [Ti(Ⅳ)(PDA) 2 ]•EtOH (Ti-PDA), was synthesized using a one-step in situ solvothermal method with a mixture of Ti( i PrO) 4 and [2,2'-bipyridine]-6,6'-dicarboxylic acid (H 2 PDA). The Ti-PDA dispalys a three-dimensional structure due to the comprising π…π contacts between the pyridine rings.Additionally, the crystals of Ti-PDA rapidly exhibit photochromic effect from colourless to dark blue after being exposed by xenon lamp or sunlight. Interestingly, this reversible transformation of color can be achieved using oxidant H 2 O 2 . Meanwhile, under the illumination of xenon lamp and with the assistance of H 2 O 2 , the microcrystals of Ti-PDA in aqueous dispersion can rapidly undergo photodegradation of methyl orange.