Encapsulating Iodine and Copper into Copper(I) Clusters Stabilized by Dichalcogenolate Ligands: Stability, Structure, and Optical Properties

The stability of
large ligated copper­(I) clusters of undeca- and dodecanuclearity encapsulating
iodide and stabilized by dithio- and diseleno-phosph­(in)­ates was investigated
by density functional theory (DFT) calculations. A bonding analysis
is provided, which shows strong iono-covalent bonding between the
iodide and its host. The electronic structures of the title compounds
suggest the possibility for interesting photoluminescent properties,
which were fully investigated by time-dependent DFT calculations including
vibronic contributions to simulate the phosphorescence spectra. The
quantum mechanical results were compared to the experimental data
obtained for the new clusters [Cu11(μ9-I)­(μ3-I)3­{Se2P­(OiPr)2}6]+ and [Cu11(μ9-I)­(μ3-I)3­(Se2PPh2)6]+, whose syntheses, X-ray structures, and full characterizations
are reported in this paper. From this combined theoretical/experimental
investigation, it is suggested that the encapsulation by the same
copper­(I) cages of a formally Cu– anion is also
possible. DFT calculations on these species are consistent with the
existence of stable two-electron superatoms.

本项研究通过密度泛函理论（DFT）计算，对包含碘化物并经二硫代和二硒代磷酸盐稳定的大型铜（I）簇团（十一核和十二核）的稳定性进行了探究。提供了键合分析，揭示了碘化物与其宿主之间强烈的离子共价键合。标题化合物的电子结构表明，其可能具有引人注目的光致发光特性，这一特性通过包括振动态贡献在内的时变DFT计算进行了全面研究，以模拟其磷光光谱。量子力学结果与实验数据进行了比较，实验数据为新簇团[Cu11(μ9-I)­(μ3-I)3­{Se2P­(OiPr)2}6]+和[Cu11(μ9-I)­(μ3-I)3­(Se2PPh2)6]+的合成、X射线结构和全面表征，相关内容已在本论文中报道。通过结合理论/实验研究，提出了一种可能性，即相同的铜（I）笼结构可以封装形式上的Cu-阴离子，且DFT计算结果与稳定双电子超原子的存在相一致。