Synthesis, characterisation, and properties of p-cymene Ruthenium(II) tetracarboxylate bipyridine complexes [(η6-p-cymene)Ru(Rn,Rn′-tcbpy)Cl][Cl]
| Autor: | Diane E.J.E. Robinson, Timothy W. Jones, Ryan E. Dawson, Gregory J. Wilson, Thomas Rüther, Yanek Hebting, Clint P. Woodward, Campbell J. Coghlan, Richard L. Cordiner |
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| Rok vydání: | 2016 |
| Předmět: |
010405 organic chemistry
Stereochemistry Ligand Decarboxylation Organic Chemistry chemistry.chemical_element 010402 general chemistry Electrochemistry 01 natural sciences Biochemistry Medicinal chemistry Dissociation (chemistry) 0104 chemical sciences Ruthenium Inorganic Chemistry Bipyridine chemistry.chemical_compound Molecular geometry chemistry Materials Chemistry Physical and Theoretical Chemistry Cyclic voltammetry |
| Zdroj: | Journal of Organometallic Chemistry. 823:136-146 |
| ISSN: | 0022-328X |
| Popis: | We report the synthesis and properties of new ruthenium-p-cymene complexes [(η6- -cymene)Ru(L)Cl][Cl] prepared from tetracarboxylic acid ligands L = 3,3′,4,4′-tetracarboxylicacid-2,2′-bipyridine (3,3′,4,4′-H4tcbpy), their methyl and ethyl ester derivatives (R4tcbpy), 4,4′,5,5′-tetracarboxylicacid-2,2′-bipyridine (4,4′,5,5′-H4tcbpy), and 4,4′-di-n-nonyl bipyridine (4,4′-dnbpy). The complexes were fully characterized by NMR, IR, MS, elemental analysis, UV–vis spectroscopy, and cyclic voltammetry. The single-crystal structure of [(η6-p-cymene)Ru(4,4′,5,5′-H4tcbpy)Cl]Cl 2 shows a ‘piano stool’ geometry with Ru-C (2.177(2)-2.231(2) A), Ru-N (2.0791–2.0801 A) distances and an N-Ru-N bond angle (77.4°) similar to equivalents in the 4,4′-dicarboxylic acid sister complex. Compared to the latter and also the 4,4′-dnbpy derivative 3, the UV–vis spectra show MLTC absorptions of the tetracarboxylates shifted to lower energy. The CVs show Ru(II/III) oxidation processes at 0.56–0.98 V (vs Fc/Fc+), depending on the ligand substitution. Changes in the electronic situation at the Ru centre reflected in the UV–vis and voltammetric data are correlated to HOMO levels calculated from photoelectron spectroscopy in air spectra recorded for all complexes. According to NMR experiments rapid ligand dissociation occurred when dissolving [(η6-p-cymene)Ru(3,3′,4,4′-Me4tcbpy)Cl]Cl 1b in DMF. In hot DMF decarboxylation led to the isolation of the 4′-dicarboxylic acid complex derivative. |
| Databáze: | OpenAIRE |
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