Hung Faan-Fung, Wu Shui-Xing, To Wai-Pong, Kwong Wai-Lun, Guan Xiangguo, Lu Wei, Low Kam-Hung, Che Chi-Ming
State Key Laboratory of Synthetic Chemistry, Institute of Molecular Functional Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, 571158, China.
Chem Asian J. 2017 Jan 3;12(1):145-158. doi: 10.1002/asia.201601414. Epub 2016 Dec 13.
Two classes of cationic palladium(II) acetylide complexes containing pincer-type ligands, 2,2':6',2''-terpyridine (terpy) and 2,6-bis(1-butylimidazol-2-ylidenyl)pyridine (C^N^C), were prepared and structurally characterized. Replacing terpy with the strongly σ-donating C^N^C ligand with two N-heterocyclic carbene (NHC) units results in the Pd acetylide complexes displaying phosphorescence at room temperature and stronger intermolecular interactions in the solid state. X-ray crystal structures of [Pd(terpy)(C≡CPh)]PF (1) and [Pd(C^N^C)(C≡CPh)]PF (7) reveal that the complex cations are arranged in a one-dimensional stacking structure with pair-like Pd ⋅⋅⋅Pd contacts of 3.349 Å for 1 and 3.292 Å for 7. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were used to examine the electronic properties. Comparative studies of the [Pt(L)(C≡CPh)] analogs by H NMR spectroscopy shed insight on the intermolecular interactions of these Pd acetylide complexes. The strong Pd-C bonds render 7 and its derivative sufficiently stable for investigation of photo-cytotoxicity under cellular conditions.
制备并对两类含钳形配体2,2':6',2''-三联吡啶（terpy）和2,6-双(1-丁基咪唑-2-亚基)吡啶（C^N^C）的阳离子钯（II）乙炔配合物进行了结构表征。用具有两个N-杂环卡宾（NHC）单元的强σ供体C^N^C配体取代terpy，导致钯乙炔配合物在室温下呈现磷光，并且在固态中具有更强的分子间相互作用。[Pd(terpy)(C≡CPh)]PF（1）和[Pd(C^N^C)(C≡CPh)]PF（7）的X射线晶体结构表明，配合物阳离子排列成一维堆积结构，1的成对状Pd⋅⋅⋅Pd接触距离为3.349 Å，7的为3.292 Å。采用密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算来研究电子性质。通过1H NMR光谱对[Pt(L)(C≡CPh)]类似物进行的对比研究揭示了这些钯乙炔配合物的分子间相互作用。强Pd-C键使7及其衍生物足够稳定，可用于在细胞条件下研究光细胞毒性。
