European Commission, Joint Research Centre (JRC), Karlsruhe, Germany.
Former Max Planck Institute for Radiation Chemistry, 45470 Mülheim a.d. Ruhr, Germany.
Molecules. 2023 Jun 28;28(13):5043. doi: 10.3390/molecules28135043.
Recent joint mass spectrometric and IR photodissociation studies have provided proof on the existence of octa-coordinated ionic lanthanide-carbonyl complexes under those extreme gaseous conditions. In contrast, in older literature concerning cryogenic studies of neutral Ln(CO) species, the highest coordination was assigned to hexa-coordinated Ln(CO) molecules. The present study aims to clarify the above controversy using matrix isolation spectroscopy and DFT calculations. In order to ensure the maximum possible coordination, the Ln(CO) complexes were synthesized in neat CO cryogenic matrices at 10 K and were investigated by infrared and UV-visible spectroscopy. The formed complexes were identified on the basis of the characteristic CO stretching frequencies of the ground-state molecules predicted by DFT calculations. Our joint experimental-theoretical analysis confirmed the preference of octa-coordinated Ln(CO) complexes in cryogenic neat CO matrices.
最近的联合质谱和红外光解研究在这些极端气体条件下提供了八配位离子镧系金属羰基配合物存在的证据。相比之下，在关于中性 Ln(CO)物种低温研究的旧文献中，最高配位数被分配给六配位 Ln(CO)分子。本研究旨在使用基质隔离光谱学和 DFT 计算来澄清上述争议。为了确保尽可能高的配位数，在 10 K 的低温 CO 基质中合成了 Ln(CO)配合物，并通过红外和紫外可见光谱进行了研究。根据 DFT 计算预测的基态分子的特征 CO 伸缩频率，确定了形成的配合物。我们的联合实验-理论分析证实了在低温纯净 CO 基质中，八配位 Ln(CO)配合物具有优势。
