Lunstroot Kyra, Nockemann Peter, Van Hecke Kristof, Van Meervelt Luc, Görller-Walrand Christiane, Binnemans Koen, Driesen Kris
Katholieke Universiteit Leuven, Department of Chemistry, Laboratory of Coordination Chemistry, Celestijnenlaan 200F bus 2404, B-3001 Leuven, Belgium.
Inorg Chem. 2009 Apr 6;48(7):3018-26. doi: 10.1021/ic8020782.
Highly luminescent anionic samarium(III) beta-diketonate and dipicolinate complexes were dissolved in the imidazolium ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C(6)mim][Tf(2)N]. The solubility of the complexes in the ionic liquid was ensured by a careful choice of the countercation of the samarium(III) complex. The samarium(III) complexes that were considered are [C(6)mim][Sm(tta)(4)], where tta is 2-thenoyltrifluoroacetonate; [C(6)mim][Sm(nta)(4)], where nta is 2-naphthoyltrifluoroacetonate; [C(6)mim][Sm(hfa)(4)], where hfa is hexafluoroacetylacetonate; and choline[Sm(dpa)(3)], where dpa is pyridine-2,6-dicarboxylate (dipicolinate) and choline is (2-hydroxyethyl)trimethyl ammonium. The crystal structures of the tetrakis samarium(III) beta-diketonate complexes revealed a distorted square antiprismatic coordination for the samarium(III) ion in all three cases. Luminescence spectra were recorded for the samarium(III) complexes dissolved in the imidazolium ionic liquid as well as in a conventional solvent, that is, acetonitrile or water for the beta-diketonate and dipicolinate complexes, respectively. These experiments demonstrate that [C(6)mim][Tf(2)N] is a suitable spectroscopic solvent for studying samarium(III) luminescence. High-luminescence quantum yields were observed for the samarium(III) beta-diketonate complexes in solution.
高发光的阴离子钐（III）β-二酮酸酯和吡啶二甲酸酯配合物溶解于咪唑离子液体1-己基-3-甲基咪唑双（三氟甲基磺酰）亚胺，即[C(6)mim][Tf(2)N]中。通过仔细选择钐（III）配合物的抗衡阳离子，确保了配合物在离子液体中的溶解度。所研究的钐（III）配合物有：[C(6)mim][Sm(tta)(4)]，其中tta为2-噻吩甲酰三氟丙酮；[C(6)mim][Sm(nta)(4)]，其中nta为2-萘甲酰三氟丙酮；[C(6)mim][Sm(hfa)(4)]，其中hfa为六氟乙酰丙酮；以及choline[Sm(dpa)(3)]，其中dpa为吡啶-2,6-二羧酸（吡啶二甲酸酯）且choline为（2-羟乙基）三甲基铵。三种四钐（III）β-二酮酸酯配合物的晶体结构均显示钐（III）离子具有扭曲四方反棱柱配位。分别记录了溶解于咪唑离子液体以及常规溶剂（β-二酮酸酯和吡啶二甲酸酯配合物分别为乙腈或水）中的钐（III）配合物的发光光谱。这些实验表明[C(6)mim][Tf(2)N]是研究钐（III）发光的合适光谱溶剂。溶液中的钐（III）β-二酮酸酯配合物具有高发光量子产率。
