Thulium acetylacetonate is a coordination compound with the formula Tm(C5H7O2)3.

This anhydrous acetylacetonate complex is often discussed but unlikely to exist per se.

The 8-coordinated dihydrate Tm(C5H7O2)3(H2O)2 is a more plausible formula based on the behavior of other lanthanide acetylacetonates.

[3][4] Upon attempted dehydration by heating under vacuum, other hydrated lanthanide tris(acetylacetonate) complexes decompose to give oxo-clusters.

[7] The acetonitrile solution of its dihydrate and the dichloromethane solution of 5-[(4-fluorobenzylidene)amino]-8-hydroxyquinoline (HL) react by heating to obtain the complex [Tm4(acac)6(L)6(μ3-OH)2].