title: Palladium(II) Acetylide Complexes with Pincer-Type Ligands: Photophysical Properties, Intermolecular Interactions, and Photo-cytotoxicity.
abstract: 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 PdIIacetylide complexes displaying phosphorescence at room temperature and stronger intermolecular interactions in the solid state. X-ray crystal structures of [Pd(terpy)(C≡CPh)]PF6(1) and [Pd(C^N^C)(C≡CPh)]PF6(7) reveal that the complex cations are arranged in a one-dimensional stacking structure with pair-like PdII⋅⋅⋅PdIIcontacts 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 by1H NMR spectroscopy shed insight on the intermolecular interactions of these PdIIacetylide complexes. The strong Pd-Ccarbenebonds render 7 and its derivative sufficiently stable for investigation of photo-cytotoxicity under cellular conditions.
authors: 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.
authors: Faan-Fung
authors: FF
authors: Hung
authors: School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, 571158, China.
authors: Shui-Xing
authors: SX
authors: Wu
authors: 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.
authors: Wai-Pong
authors: WP
authors: To
authors: 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.
authors: Wai-Lun
authors: WL
authors: Kwong
authors: 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.
authors: Xiangguo
authors: X
authors: Guan
authors: 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.
authors: Wei
authors: W
authors: Lu
authors: 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.
authors: Kam-Hung
authors: KH
authors: Low
authors: 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.|HKU Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, 518053, China.
authors: Chi-Ming
authors: CM
authors: Che
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry / Q000494:pharmacology*; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology*; D011789:Quantum Theory; D013329:Structure-Activity Relationship
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D017319:Photosensitizing Agents; D011725:Pyridines; D010165:Palladium
keywords: intermolecular interactions; palladium; phosphorescence; photo-cytotoxicity