Sensitization with dyes is the most promising option to narrow the band gap and improve visible-light absorption of TiO2. As ideal structure and reaction models of TiO2, titanium oxo clusters (TOCs) with exact crystal structure are beneficial for further understanding the structure-property relationship of TiO2. Most reports mainly focus on the synthesis and properties of TOCs, but research on the band-gap tuning of TOCs at the large range of 3.7-2.0 eV by chromophore ligands (CLs) has been lacking. Herein, six new Ti-6-core-based TOCs (Ti-6-TOCs) were successfully synthesized by using CLs in a simple and general approach. Each Ti-6-TOC structure contains two Ti-3(mu(3)-O) units featuring a flat or pyramidal mode as building blocks. Five Ti-6-core structure types were present among the six Ti-6-TOCs, which enriched the family of hexanuclear TOCs. To be noted, the band-gap values were tuned at a wide range of 3.41-1.98 eV by controlling the type and number of the CLs 2-hydroxypyridine, salicylaldoxime, and catechol in the structure. Density functional theory calculation revealed that the lowest-energy bands of these Ti-6-TOCs are attributed to the CL-to-TiO core charge-transfer bands. This work provides a precise and wide-ranged band-gap tuning method for TOCs. Additionally, the six Ti-6-TOCs exhibit good photocurrent response.