Nicholas Aaron D, Arteaga Ana, Ducati Lucas C, Buck Edgar C, Autschbach Jochen, Surbella Robert G
Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA, 99354, USA.
Department of Fundamental Chemistry Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, 05508-000, Brazil.
Chemistry. 2023 Jul 20;29(41):e202300077. doi: 10.1002/chem.202300077. Epub 2023 Jun 13.
We report the structural, vibrational, and optical properties of americium formate (Am(CHO ) ) crystals synthesized via the in situ hydrolysis of dimethylformamide (DMF). The coordination polymer features Am ions linked by formate ligands into a three-dimensional network that is isomorphous to several lanthanide analogs, (e. g., Eu , Nd , Tb ). Structure determination revealed a nine-coordinate Am metal center that features a unique local C symmetry. The metal-ligand bonding interactions were investigated by vibrational spectroscopy, natural localized molecular orbital calculations, and the quantum theory of atoms in molecules. The results paint a predominantly ionic bond picture and suggest the metal-oxygen bonds increase in strength from Nd-O<Eu-O<Am-O. The optical properties were probed using diffuse reflectance and photoluminescence spectroscopies. Notably, the rarely reported D → F emission band is observed and dominates the emission spectrum. This behavior is unusual and is attributed to the C coordination environment of the metal center.
我们报道了通过二甲基甲酰胺（DMF）原位水解合成的甲酸镅（Am(CHO₂)₃）晶体的结构、振动和光学性质。该配位聚合物的特征是Am离子通过甲酸根配体连接成三维网络，该网络与几种镧系元素类似物（如Eu³⁺、Nd³⁺、Tb³⁺）同构。结构测定揭示了一个九配位的Am金属中心，其具有独特的局部C₂对称性。通过振动光谱、自然定域分子轨道计算和分子中的原子量子理论研究了金属-配体键相互作用。结果描绘了一幅主要为离子键的图景，并表明金属-氧键的强度从Nd-O＜Eu-O＜Am-O递增。使用漫反射和光致发光光谱对光学性质进行了探测。值得注意的是，观察到了很少报道的⁵D₀→⁷F₀发射带，且该发射带主导了发射光谱。这种行为是不寻常的，归因于金属中心的C₂配位环境。
