A Novel Heteroditopic Terpyridine-Pincer Ligand as Building Block for Mono- and Heterometallic Pd(II) and Ru(II) Complexes
| Autor: | Gagliardo, M., Rodríguez, G., Dam, H.H., Lutz, M., Spek, A.L., Havenith, R.W.A., Coppo, P., De Cola, L., Hartl, F., van Klink, G.P.M., van Koten, G., Homogene katalyse en materialen, Quantumchemie, R¿ntgenparticipatieprogramma, Dep Scheikunde |
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| Přispěvatelé: | Homogene katalyse en materialen, Quantumchemie, R¿ntgenparticipatieprogramma, Dep Scheikunde, Homogeneous and Supramolecular Catalysis (HIMS, FNWI) |
| Rok vydání: | 2006 |
| Předmět: |
010405 organic chemistry
Ligand Stereochemistry Metalation Bridging ligand 010402 general chemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences Stille reaction Inorganic Chemistry chemistry.chemical_compound chemistry International (English) Moiety Physical and Theoretical Chemistry Terpyridine Pincer ligand Bifunctional |
| Zdroj: | Inorganic Chemistry, 45(5), 2143. American Chemical Society Inorganic Chemistry, 45(5), 2143-2155. American Chemical Society |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic051967c |
| Popis: | A palladium-catalyzed Stille coupling reaction was employed as a versatile method for the synthesis of a novel terpyridine-pincer (3, TPBr) bridging ligand, 4'-{4-BrC6H2(CH2NMe2)2-3,5}-2,2':6',2' '-terpyridine. Mononuclear species [PdX(TP)] (X = Br, Cl), [Ru(TPBr)(tpy)](PF6)2, and [Ru(TPBr)2](PF6)2, synthesized by selective metalation of the NCNBr-pincer moiety or complexation of the terpyridine of the bifunctional ligand TPBr, were used as building blocks for the preparation of heterodi- and trimetallic complexes [Ru(TPPdCl)(tpy)](PF6)2 (7) and [Ru(TPPdCl)2](PF6)2 (8). The molecular structures in the solid state of [PdBr(TP)] (4a) and [Ru(TPBr)2](PF6)2 (6) have been determined by single-crystal X-ray analysis. Electrochemical behavior and photophysical properties of the mono- and heterometallic complexes are described. All the above di- and trimetallic Ru complexes exhibit absorption bands attributable to (1)MLCT (Ru --tpy) transitions. For the heteroleptic complexes, the transitions involving the unsubstituted tpy ligand are at a lower energy than the tpy moiety of the TPBr ligand. The absorption bands observed in the electronic spectra for TPBr and [PdCl(TP)] have been assigned with the aid of TD-DFT calculations. All complexes display weak emission both at room temperature and in a butyronitrile glass at 77 K. The considerable red shift of the emission maxima relative to the signal of the reference compound [Ru(tpy)2]2+ indicates stabilization of the luminescent 3MLCT state. For the mono- and heterometallic complexes, electrochemical and spectroscopic studies (electronic absorption and emission spectra and luminescence lifetimes recorded at room temperature and 77 K in nitrile solvents), together with the information gained from IR spectroelectrochemical studies of the dimetallic complex [Ru(TPPdSCN)(tpy)](PF6)2, are indicative of charge redistribution through the bridging ligand TPBr. The results are in line with a weak coupling between the {Ru(tpy)2} chromophoric unit and the (non)metalated NCN-pincer moiety. |
| Databáze: | OpenAIRE |
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