A new approach to the effects of isocyanide (CN-R) ligands on the luminescence properties of cycloplatinated( ii ) complexes

• Published in: New journal of chemistry 2017, Vol.41 (24), p.15347-15356
• Main Authors: Shahsavari, Hamid R., Babadi Aghakhanpour, Reza, Hossein-Abadi, Mojdeh, Golbon Haghighi, Mohsen, Notash, Behrouz, Fereidoonnezhad, Masood
• Format: Article
• Language: English
• Subjects: Crystallography; Density functional theory; Ligands; Luminescence; NMR; NMR spectroscopy; Nuclear magnetic resonance; Optical properties; Photoluminescence; Single crystals; Spectrum analysis
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/C7NJ03110F

The present investigation highlights the effects of the presence of isocyanide ligands on the emission properties of cycloplatinated( ii ) compounds. The new complexes with a general formula of [Pt(ppy)(Me)(CN-R)] (ppy = deprotonated 2-phenylpyridine and R = benzyl ( 1 ), 2-naphthyl ( 2 ), tert -butyl ( 3 )) were produced using a quite simple method. Then, the resulting complexes were accurately identified employing multinuclear 1D and 2D NMR spectroscopy and two of them ( 1 and 3 ) were further authenticated by single crystal X-ray crystallography. The optical properties of 1–3 were investigated by UV-visible and photoluminescence spectroscopy. The obtained photophysical data were supported by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The concurrent presence of Me and isocyanide ligands as two strong carbon σ-donor ancillary ligands in the structure of these cycloplatinated( ii ) complexes was probably responsible for the strong luminescence observed at room temperature. This was confirmed by the obtained relatively high quantum yield values (0.41, 0.56 and 0.40 for 1 , 2 and 3, respectively). The luminescence investigation of the complexes under different conditions indicates that R substituents in the structures of isocyanide ligands have a remarkable influence on the emission properties.