A new solid-state compound containing a heterobimetallic cluster of U and Ta, UTa 2 O(S 2 ) 3 Cl 6 , has been synthesized and its structure has been characterized by single-crystal X-ray diffraction methods. UTa 2 O(S 2 ) 3 Cl 6 was synthesized from UCl 4 and Ta 1.2 S 2 at 883 K. The O is believed to have originated in the Ta 1.2 S 2 reactant. The compound crystallizes in the space group P1 ¯of the triclinic system. The structure comprises a UTa 2 unit bridged by m 2 -S 2 and m 3 -O groups. Each Ta atom bonds to two m 2 -S 2 , the m 3 -O, and two terminal Cl atoms. Each U atom bonds to two m 2 -S 2 , the m 3 -O, and four Cl atoms. The Cl atoms bridge in pairs to neighboring U atoms to form a ribbon structure. The bond distances are normal and are consistent with formal oxidation states of + IV/ + V/-II/-I/-I for U/Ta/O/S/Cl, respectively. The optical absorbance spectrum displays characteristic transition peaks near the absorption edge. Density functional theory was used to assign these peaks to transitions between S 1-valence-band states and empty U 5f-6d hybrid bands. Density-of-states analysis shows overlap between Ta 5d and U bands, consistent with metal-metal interactions.