Synthesis of C-functionalized acetylacetone and its europium complex. Preparation and study of luminescence of europium-containing sol-gel films

New fuctionalized ligand 3-(3′-triethoxysilylpropylaminocarbonyl)pent-2-on-3-en-4-ol (EtO)₃SiCH₂·CH₂CH₂NHC(O)-CC(O)CH₃]=C(OH)CH₃] (I) containing ketoenol and triethoxysilyl groups is synthesized from 3-triethoxysilylpropyl isocyanate (EtO)₃SiCH₂CH₂CH₂N=C=O and acetylacetone. The reaction is accompanied by the formation of 2-(3′-triethoxysilylpropylaminocarboxy)-pent-2-en-4-one (EtO)₃SiCH₂CH₂·CH₂NHC(O)-OC(CH₃)=CH-C(O)CH₃ (II), the product of addition of acetylacetone enol form to isocyanate group. The ratio of amide I and urethane II forms is 7:3. Europium(III) tris3-(3′-triethoxysilylpropylaminocarbonyl) pent-2-on-3-en-4-olate] is prepared from I and Eu(i-OPr)₃. An alternative pathway consists in the reaction of europium tris(acetylacetonate) with 3-triethoxysilylpropyl isocyanate. Conditions of formation of transparent europium-containing sol-gel films were developed. Thermal stability and photoluminescence of the films were investigated.