Sc(III), Eu(III), and Gd(III) Complexes with Macrocyclic Cavitand Cucurbit[6]uril: Synthesis and Crystal Structures
Sc(III), Eu(III), and Gd(III) Complexes with Macrocyclic Cavitand Cucurbit[6]uril: Synthesis and Crystal Structures
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DOI:
10.1007/s11173-005-0167-2
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发表时间:
2005-11
影响因子:
1.9
通讯作者:
A. A. Tripol’skaya-A.;E. A. Mainicheva;T. V. Mit’kina;O. A. Geras’ko;D. Naumov;V. Fedin
中科院分区:
文献类型:
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作者:
A. A. Tripol’skaya-A.;E. A. Mainicheva;T. V. Mit’kina;O. A. Geras’ko;D. Naumov;V. Fedin
Slow evaporation of solutions of Sc and Eu nitrates with macrocyclic cavitand cucurbit[6]uril gives crystals of isostructural complexes [Sc(NO3)(H2O)4(C36H36N24O12)](NO3)2⋅ 8.5H2O (space groupPna21,a= 32.0065(18) Å,b= 14.7904(8) Å,c= 11.5774(6) Å,V= 5480.6(5) Å3,Z= 4) and [Eu(NO3)(H2O)4(C36H36N24O12)](NO3)2⋅ 6.75H2O (space groupPna21,a= 31.9525(17) Å,b= 14.7203(8) Å,c= 11.8592(6) Å,V= 5578.0(5) Å3,Z= 4). The metal to ligand ratio in these complexes is 1 : 1; the complexes are obtained at 0.025–0.1 mol/l concentrations of the metals in solutions. With higher lanthanide concentrations (0.7–1 mol/l), the 2 : 1 complex with cucurbit[6]uril is formed of the composition [{ Gd(NO3)(H2O)5}2(C36H36N24O12)](NO3)4⋅ 6.5H2O (space group,a= 13.3972(6) Å,b= 14.4994(5) Å,c= 18.3290(8) Å, α = 73.5610(10)°, β = 87.2590(10)°, γ = 87.5540(10)°,V= 3409.4(2) Å3,Z= 2) and isotypical complex [{Gd(NO3)(H2O)5}2{(C5H5N) ⊂ (C36H36N24O12)}](NO3)4⋅ 8H2O with a pyridine molecule inside the cucurbit[6]uril cavity (space groupP21/n,a= 14.8263(6) Å,b= 13.3688(7) Å,c= 18.5970(9) Å, β = 107.5860(10)°,V= 3513.8(3) Å3,Z= 2). According to X-ray diffraction data, the metal atoms of the title complexes coordinate the O atoms in portals of cucurbit[6]uril molecules.