A 2:1 Dicationic Complex of Tetraethyl Methylenebisphosphonate with Uranyl Ion in Acetonitrile and Ionic Liquids
详细信息 查看全文
- 作者：Yupeng Liu ; Taiwei Chu ; Xiangyun Wang
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：January 18, 2013
- 年：2013
- 卷：52
- 期：2
- 页码：848-854
- 全文大小：428K
- 年卷期：v.52,no.2(January 18, 2013)
- ISSN：1520-510X
文摘
A new 2:1 dicationic complex formed by TEMBP with uranyl ion in acetonitrile and two hydrophobic ILs, [BMIm][NTf2] and [N4111][NTf2], has been identified with combination of optical spectroscopic and mass spectrometric studies. With excess of TEMBP ligand (L/U > 2.0), the uranyl is completely coordinated by two ligands to form a dicationic complex [UO2(TEMBP)2]2+. The UV鈥搗is spectra of [UO2(TEMBP)2]2+ in acetonitrile and in the two ILs are similar. The vibronic fine structures in UV鈥搗is spectrum of [UO2(TEMBP)2]2+ show characters of tetragonal coordination in the uranyl equatorial plane. The symmetry of proposed structure of [UO2(TEMBP)2]2+ is D2h, and its UV鈥搗is spectrum is tentatively interpreted based on the structural similarity to the well studied [UO2Cl4]2鈥?/sup> complex. The luminescence emission spectrum of [UO2(TEMBP)2]2+ shows typical vibronic bands, having a mirror relationship with the 455鈥?00 nm region of the corresponding absorption spectrum. The stoichiometry of [UO2(TEMBP)2]2+ is confirmed by electrospray ionization鈥搃on trap mass spectrometry (ESI-ITMS) studies with acetonitrile as solvent. The 鈥渘aked鈥?dication (m/z 423) is characterized by the remarkable eight peaks with interval of 14 m/z units in its tandem mass spectra, representing the fragmentation of ligands by losing C2H4 units from their ethoxy groups. However, the dication tends to exist as a weak adduct with either an additional ligand or an anion in the ESI mass spectrum. The adducts {[UO2(TEMBP)2]2+ + TEMBP} (m/z 567) and {[UO2(TEMBP)2]2+ + [ClO4]鈭?/sup>} (m/z 945) are favorable in pure acetonitrile, while only one adduct {[UO2(TEMBP)2]2+ + [NTf2]鈭?/sup>} (m/z 1126) is predominant in [BMIm][NTf2] (diluted with acetonitrile). The results of ESI-ITMS study are consistent with those of optical spectroscopic studies.