Star hexacarboxylate: synthesis, crystal structure and luminescent properties of its terbium complex

Abstract

A new star host, hexakis (carboxylphenyl-2-thiolmethyl)benzene (1H6), has been synthesized by a simple one-step condensation procedure with the high yield. Crystal structure of the DMSO adduct 1H6·6DMSO (2) reveals it to be rhombohedral crystal system, space group R-3, with a = b = 2.4129(2), c = 1.1576(3) nm, α= β = 90°, γ= 120°, ∨= 5.837(2) nm3, Z = 3. The six arms of side benzoic acid rings and the H-bonded DMSO molecules are located alternatively above and below the central benzene plane with “1,3,5-up/2,4,6-down” conformation. Terbium complex (Tb21)2Py·9H2O (3) was prepared in hot pyridine, which shows bright characterized Tb(III) emission with a longer lifetime and higher luminescent intensity than that of the corresponding terbium benzoate in solid state. These observations suggest that host 1 is a good antenna for sensitizing TbIII emission.

通過簡單的一步縮合反應合成了新型主體分子——星狀六苯甲酸(1H_6),測定了其DMSO加合物1H_6·6DMSO(2)的晶體結構。晶體屬三方晶系,空間群為R-3,晶胞參數a=b=2.4129(2),c=1.1576(3)um,α=β=90°,γ=120°,V=5.837(2)um3,Z=3。六個DMSO和氫鍵鍵接的端基苯甲酸交替排列在中心苯環的上下方,形成“1,3,5-位基因向上;2,4,6-位基團向下”的雙三棱柱結構。在吡啶中制備了1的鋱配合物(Tb_21)_2Py·9H_2O(3),該配合物發射明亮的鋱離子特征熒光。與相應苯甲酸鋱的固體粉末的熒光光譜相比,化合物3有更高的發光強度和較長的激發態壽命。說明1能很好地包絡中心鋱離子,是好的天線結構配體。