The complex is a tetramer of binuclear Cr2(OH)3(OAc)3. The subunits are linked by acetate and hydroxide ligands. The oxidation state of chromium is +3, which explains the stability of the complex since octahedral d3 ions give kinetically robust complexes. Overall, the complex's structure is unusual compared to other transition metal carboxylate complexes.
Eshel, Michal; Bino, Avi; Felner, Israel; Johnston, David C.; Luban, Marshall; Miller, Lance L. (2000). "Polynuclear Chromium(III) Carboxylates. 1. Synthesis, Structure, and Magnetic Properties of an Octanuclear Complex with a Ring Structure". Inorganic Chemistry. 39 (7): 1376–1380. doi:10.1021/ic9907009. PMID 12526439. /wiki/Doi_(identifier) ↩