Solid-State and Solution-State Coordination Chemistry of Lanthanide(III) Complexes with (Pyrazol-1-yl)acetic Acid

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• 作者：Xiao-Yan Chen ; George S. Goff ; Brian L. Scott ; Michael T. Janicke ; Wolfgang Runde
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：March 18, 2013
• 年：2013
• 卷：52
• 期：6
• 页码：3217-3224
• 全文大小：424K
• 年卷期：v.52,no.6(March 18, 2013)
• ISSN：1520-510X

文摘

As a precursor of carboxyl-functionalized task-specific ionic liquids (TSILs) for f-element separations, (pyrazol-1-yl)acetic acid (L) can be deprotonated as a functionalized pyrazolate anion to coordinate with hard metal cations. However, the coordination chemistry of L with f-elements remains unexplored. We reacted L with lanthanides in aqueous solution at pH = 5 and synthesized four lanthanide complexes of general formula [Ln(L)<sub>3sub>(H<sub>2sub>O)<sub>2sub>]路nH<sub>2sub>O (1, Ln = La, n = 2; 2, Ln = Ce, n = 2; 3, Ln = Pr, n = 2; 4, Ln = Nd, n = 1). All complexes were characterized by single crystal X-ray diffraction analysis revealing one-dimensional chain formations. Two distinct crystallographic structures are governed by the different coordination modes of carboxylate groups in L: terminal bidentate and bridging tridentate (1鈥?b>3); terminal bidentate, bridging bidentate, and tridentate coordination in 4. Comparison of the solid state UV鈥搗is鈥揘IR diffuse reflectance spectra with solution state UV鈥搗is鈥揘IR spectra suggests a different species in solution and solid state. The different coordination in solid state and solution was verified by distinctive <sup>13sup>C NMR signals of the carboxylate groups in the solid state NMR.