Oxidation of linear trinuclear ruthenium complexes [Ru(3)(dpa)(4)Cl(2)] and [Ru(3)(dpa)(4)(CN)(2)]: synthesis, structures, electrochemical and magnetic properties |
| |
Authors: | Kuo Ching-Kuo Liu Isiah Po-Chun Yeh Chen-Yu Chou Chung-Hsien Tsao Ting-Bin Lee Gene-Hsiang Peng Shie-Ming |
| |
Institution: | Department of Chemistry, National Taiwan University, No 1, Roosevelt Rd., Sec. 4, Taipei, Taiwan. |
| |
Abstract: | The neutral, monocationic, and dicationic linear trinuclear ruthenium compounds Ru(3)(dpa)(4)(CN)(2)], Ru(3)(dpa)(4)(CN)(2)]BF(4)], Ru(3)(dpa)(4)Cl(2)]BF(4)], and Ru(3)(dpa)(4)Cl(2)]BF(4)](2) (dpa=the anion of dipyridylamine) have been synthesized and characterized by various spectroscopic techniques. Cyclic voltammetric and spectroelectrochemical studies on the neutral and oxidized compounds are reported. These compounds undergo three successive metal-centered one-electron-transfer processes. X-ray structural studies reveal a symmetrical Ru(3) unit for these compounds. While the metal--metal bond lengths change only slightly, the metal--axial ligand lengths exhibit a significant decrease upon oxidation of the neutral complex. The electronic configuration of the Ru(3) unit changes as the axial chloride ligands are replaced by the stronger "pi-acid" cyanide axial ligands. Magnetic measurements and (1)H NMR spectra indicate that Ru(3)(dpa)(4)Cl(2)] and Ru(3)(dpa)(4)Cl(2)]BF(4)](2) are in a spin state of S=0 and Ru(3)(dpa)(4)Cl(2)]BF(4)], Ru(3)(dpa)(4)(CN)(2)], and Ru(3)(dpa)(4)(CN)(2)]BF(4)] are in spin states of S=1/2, 1, and 3/2, respectively. These results are consistent with molecular orbital (MO) calculations. |
| |
Keywords: | density functional calculations metal–metal interactions multiple bonds N ligands ruthenium |
本文献已被 PubMed 等数据库收录! |
|