Phosphorescent Platinum(II) Complexes Featuring Chelated Acetoxime Pyrazoles: Synthetic, Structural, and Photophysical Study
| Autor: | Mikhail V. Dorogov, Alexander S. Novikov, Yuri Novozhilov, Oksana Ronzhina, Dmitrii S. Bolotin, Ilya E. Kolesnikov, Vitaliy V. Suslonov, Vadim Yu. Kukushkin, Mikhail Krasavin |
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| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Absorption spectroscopy 010405 organic chemistry chemistry.chemical_element General Chemistry Pyrazole Electron acceptor 010402 general chemistry Oxime Photochemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound chemistry Cascade reaction Luminescence Phosphorescence Platinum |
| Zdroj: | ChemistrySelect. 1:456-461 |
| ISSN: | 2365-6549 |
| DOI: | 10.1002/slct.201600130 |
| Popis: | Treatment of cis-[PtCl2(Me2SO)2] with the pyrazole acetoximes p-RC6H4{CN(H)NCCH}CH2C(Me)=NOH (R=OMe, H, F, Cl, CN, NO2), prepared by a cascade reaction from the vinyl isoxazoles p-RC6H4C(H)=C(H){CONCC(NO2)}Me, leads to the complexes [PtCl2(Ar{CN(H)NCCH}CH2C(Me)=NOH)] (71–88 %). The complexes exhibit solid state room temperature phosphorescence with emission maxima in the region of 644–691 nm and biexponential relaxation with τ1 ≈ 2 ms and τ2 ≈ 0.32 ms. In the platinum compounds, substituents R affect phosphorescence quantum yields, which increase by one order of magnitude on going from electron acceptor (R=NO2; 0.2 %) to electron-donor groups (R=OMe; 2.0 %). Based upon theoretical TD-DFT calculations using the CAM−B3LYP functional, the absorption spectra were attributed to metal-to-ligand charge transfer (1MLCT) and ligand-to-ligand charge transfer (1LLCT) processes. The pyrazole acetoximes and their complexes were characterized by elemental analyses (C, H, N), HRESI-MS, FTIR, 1H NMR (for metal-free species), and CP-MAS TOSS 13C{1H} NMR (for the platinum complexes). In addition, two complexes were studied by single-crystal X-ray diffraction. |
| Databáze: | OpenAIRE |
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