The design of hybrid materials relies on an understanding of the structural building units present in the reaction, but identifying these building units in solution can be hampered by difficulties in the interpretation of the characteristic spectroscopic signals. The importance of speciation and intermolecular interactions in identifying building units was explored in the uranyl squarate and croconate system with the isolation and characterization of six compounds: (USq1) [C₄H₁₂N₂][(UO₂)(C₄O₄)₂(H₂O)]·(H₂O), (USq2) [C₅H₆N][(UO₂)(C₄O₄)(μ₂-OH)]·2H₂O, (USq3) [C₂H₁₀N₂]₂[(UO₂)₆(C₄O₄)₃(μ₃-O)₂(μ₂-OH)₆], (UCr1) [C₄H₁₂N₂]₂[(UO₂)(C₅O₅)₃(H₂O)]·3H₂O, (UCr2) [C₅H₆N]₄[(UO₂)₄(C₅O₅)₄(μ₂-OH)₄(H₂O)₄], and (UCr3) [C₂H₁₀N₂]₅[(UO₂)₆(C₅O₅)₆(μ₃-O)₂(μ₂-OH)₆(H₂O)₄]. These compounds are built upon the traditional monomeric, dimeric, and trimeric uranyl oligomers that occur upon hydrolysis of the metal center. A combined solid and solution spectroscopic approach was used to understand the impact of uranyl oligomerization, ligand coordination, and intermolecular interactions. The v₁(UO₂²⁺) Raman shift and the UV–visible spectrum for each solid uranyl-squarate and uranyl-croconate compound reveals important information regarding the impact of π–π interactions on the chemical properties of uranyl hybrid materials.

中文翻译：

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铀酰方酸和croconate系统的光谱分析：评估溶液和固态相之间的差异

杂化材料的设计依赖于对反应中存在的结构建筑单元的理解，但在解析特征光谱信号时会遇到困难，因此无法确定溶液中的这些建筑单元。在铀酰方酸和丁烯酸体系中，通过分离和表征以下六种化合物，探讨了物种形成和分子间相互作用的重要性：（USq1）[C ₄ H ₁₂ N ₂ ] [（UO ₂）（C ₄ O _4））₂（H ₂ O）]·（H ₂ O），（USq2）[C ₅ H₆ N] [（UO ₂）（C ₄ Ò ₄）（μ ₂ -OH）]·2H ₂ O，（USq3）[C ₂ H ^ ₁₀ Ñ ₂ ] ₂ [（UO ₂）₆（C ₄ Ò ₄）₃（μ ₃ -O）₂（μ ₂ -OH）₆ ]，（UCR1）[C ₄ H ^ ₁₂ ñ ₂ ] ₂ [（UO ₂）（C ₅ ø ₅）₃（H ₂ O）]·3H ₂ O，（UCR2）[C ₅ H ^ ₆ N] ₄ [（UO ₂）₄（C ₅ ø ₅）₄（μ ₂ -OH）₄（H ₂ O）₄ ]，和（UCr3）[C ₂ H ^ ₁₀ ñ ₂ ] ₅ [（UO ₂）₆（C ₅ ø ₅）₆（μ ₃ -O）₂（μ ₂ -OH）₆（H ₂ O）₄ ]。这些化合物建立在传统的单体，二聚和三聚铀酰低聚物上，而传统的单体，二聚和三聚铀酰低聚物是在金属中心水解时出现的。结合使用了固溶和溶液光谱的方法来了解铀酰低聚，配体配位和分子间相互作用的影响。每个固体铀酰-方酸和尿烷-croconate化合物的v ₁（UO ₂ ²⁺）拉曼位移和紫外可见光谱揭示了有关π-π相互作用对铀酰杂化材料化学性质的影响的重要信息。