多色稀土有机配合物闪烁体的合成及X射线成像应用

Synthesis and X⁃ray imaging application of lanthanide⁃organic complex⁃based scintillators

以2,5⁃二氟苯甲酸(HDFBA)为第一配体,2,2'∶6',2″⁃三联吡啶(terpy)、1,10⁃菲咯啉(phen)为第二配体,成功合成4种稀土有机配合物闪烁体:[Tb(DFBA)3(terpy)(H_(2)O)](1)、[Eu(DFBA)3(terpy)(H_(2)O)](2)、[Tb(DFBA)3(phen)](3)、[Eu(DFBA)3(phen)](4)。这些稀土有机配合物闪烁体展现出优异的X射线剂量响应性、光稳定性以及高达(25100±2000)photons·MeV-1的稳态X射线激发的相对光产额。通过调节配合物中Eu^(3+)和Tb^(3+)的物质的量之比,实现了从绿色到红色的多色发光。将它们以一定的比例掺入聚乙烯醇(PVA)基质中获得均匀闪烁体薄膜,实现了高分辨(11.2 lp·mm^(-1))X射线成像。

Lanthanide⁃organic complex scintillators,known for their structural flexibility and optical tunability,have shown great promise as X⁃ray scintillators.Herein,four lanthanide⁃organic complex scintillators,named[Tb(DFBA)_(3)(terpy)(H_(2)O)](1),[Eu(DFBA)_(3)(terpy)(H_(2)O)](2),[Tb(DFBA)_(3)(phen)](3),and[Eu(DFBA)_(3)(phen)](4),were suc⁃cessfully synthesized by solvent volatilization using 2,5⁃difluoro benzoic acid(HDFBA)as the first ligand,2,2'∶6',2″⁃terpy(terpy)and 1,10⁃phenanthroline(phen)as the second ligands.The incorporation of phen in these complexes enhanced their molecular structural rigidity and coordination field stability,reduced non⁃radiative transitions,and resulted in excellent luminescent properties.The fluorine⁃substituted organic ligands minimized non⁃radiative O—H vibrations,thereby improving luminescence efficiency.As a result,the lanthanide⁃organic complex⁃based scintil⁃lators exhibited high radiation responsiveness and excellent X⁃ray absorption capability,and achieved a high steady⁃state X⁃ray excited relative light yield of(25100±2000)photons·MeV^(-1).Additionally,scintillators with multi⁃color luminescence ranging from green to red were fabricated by manipulating the molar ratio of Eu^(3+)to Tb^(3+)ions.Finally,when incorporated into a polyvinyl alcohol(PVA)matrix,a uniform,flexible scintillator film with high⁃resolution X⁃ray imaging(11.2 lp·mm^(-1))was obtained.These findings demonstrate that the introduction of a second ligand and appropriate hydrophobic groups(such as fluorine substitution)hold significant potential for designing high⁃performance lanthanide⁃organic complex scintillators for high⁃resolution X⁃ray imaging.CCDC:2294866,1;2294867,2;2294869,3;2294868,4.