Electronic and Magnetic Communication in Mixed-Valent and Homovalent Ruthenium Complexes Containing Phenylcyanamide Type Bridging Ligands
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- 作者：Muriel Fabre ; Jacques Bonvoisin
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：February 7, 2007
- 年：2007
- 卷：129
- 期：5
- 页码：1434 - 1444
- 全文大小：292K
- 年卷期：v.129,no.5(February 7, 2007)
- ISSN：1520-5126
文摘
Four new phenylcyanamido-bridge dinuclear ruthenium complexes [{Ru(tpy)(thd)}2(
-L)] withtpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione and L = dcbp = 4,4'-dicyanamidobiphenyl; bcpa = bis(4-cyanamidophenyl)acetylene; bcpda = bis(4-cyanamidophenyl)diacetylene; bcpea= 9,10,-bis(4-cyanamidophenylethynyl)anthracene have been prepared and fully characterized. The mixedvalent Ru(II)Ru(III) and homovalent paramagnetic Ru(III)Ru(III) forms of all the complexes wereelectrochemically generated and studied by UV-vis-NIR and EPR spectroscopy. Electronic communicationwas quantified by the electronic coupling parameter Vab extracted from intervalence measurements in thenear IR area, and magnetic communication was quantified in terms of the exchange coupling constant J,accessible from the intensity of the EPR signal when varying the temperature. Exponential decays for bothelectronic and magnetic coupling versus intermetallic distance were obtained and discussed.
-L)] withtpy = 2,2':6',2' '-terpyridine, thd = 2,2,6,6-tetramethyl-3,5-heptanedione and L = dcbp = 4,4'-dicyanamidobiphenyl; bcpa = bis(4-cyanamidophenyl)acetylene; bcpda = bis(4-cyanamidophenyl)diacetylene; bcpea= 9,10,-bis(4-cyanamidophenylethynyl)anthracene have been prepared and fully characterized. The mixedvalent Ru(II)Ru(III) and homovalent paramagnetic Ru(III)Ru(III) forms of all the complexes wereelectrochemically generated and studied by UV-vis-NIR and EPR spectroscopy. Electronic communicationwas quantified by the electronic coupling parameter Vab extracted from intervalence measurements in thenear IR area, and magnetic communication was quantified in terms of the exchange coupling constant J,accessible from the intensity of the EPR signal when varying the temperature. Exponential decays for bothelectronic and magnetic coupling versus intermetallic distance were obtained and discussed.