TY - JOUR
T1 - Preparation, spectroscopy, and electrochemistry of cyano-bridged bis(oxo-centered-hexa(μ-acetato)-triruthenium) complexes
AU - Zhang, Hua Xin
AU - Sasaki, Yoichi
AU - Abe, Masaaki
AU - Zhang, Yi
AU - Ye, Shen
AU - Osawa, Masatoshi
N1 - Funding Information:
This work was financially supported in part by the Ministry of Education, Culture, Sports, Science and Technology of Japan . H.-X.Z. is grateful to the Japan Society for the Promotion of Science for a postdoctoral fellowship ( P05123 ). The Project was sponsored by the Scientific Research Foundation of Guangxi University (Grant No. XDZ140116 ), the Hundred Talents Program of Guangxi Province and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry .
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/8/11
Y1 - 2015/8/11
N2 - Preparation, characterization, and properties of a cyano bridged complex containing the Ru3(μ3-O) cores, [{Ru3(μ3-O) (μ-CH3COO)6(py)2}2(μ-CN)](PF6) ([1]PF6) (py = pyridine), are reported and compared with the properties of [{Ru3(μ3-O)(μ-CH3COO)6(py)2}(μ-CN){Ru3(μ3-O)(μ-CH3COO)6(py)(CO)}] (2). The cyclic voltammogram of [1]+ in 0.1 M (n-Bu)4NPF6-CH2Cl2 solution with an Ag/AgCl reference electrode showed a series of redox waves assigned to the processes Ru3II,II,III/Ru3II,III,III (-1.70 V, -1.52 V), Ru3II,III,III/Ru3III,III,III (-0.37 V, -0.19 V), Ru3III,III,III/Ru3III,III,IV (+1.08 V), and Ru3III,III,IV/Ru3III,IV,IV (+2.03 V). Upon bridge formation the redox waves of the C-bonded Ru3 moiety of [1]+ stay at the similar potential region to those of Ru3(μ3-O)(μ-CH3COO)6(py)2(CN) (3) with a unidentate CN-, so that the enhancement of the π-back donation does not operate, indicating that the Ru3O core is not a good π-donor. Complex 2 showed five redox waves for the processes Ru3II,II,III/Ru3II,III,III (-1.15 V), Ru3II,III,III/Ru3III,III,III (-0.21 V, +0.55 V), and Ru3III,III,III/Ru3III,III,IV (+1.05 V, +1.35 V). The redox potential (-1.15 V) of the Ru3II,II,III/Ru3II,III,III process of the Ru3(py) (CO) unit in 2 showed a negative shift in comparison to that (-0.84 V) of [Ru3II,III,III(μ3-O) (μ-CH3COO)6(py)2(CO)]. The infrared spectroelectrochemistry of [1]+ and 2 in 0.1 M n-Bu4NPF6-CH2Cl2 solutions revealed that the frequencies of the stretching vibration ν(CN) of the cyanide increased with the increase in the isovalent oxidation states of [1]+ but those in the Ru3O-based mixed-valence states, Ru3II,III,III-Ru3III,III,III, and Ru3III,III,III-Ru3III,III,IV, were significantly smaller, which was possibly due to the effective electronic coupling through the CN- bridge between the two Ru3 units with different oxidation states. In contrast, such coupling was not observed for 2 that has two Ru3 units with significantly different ligand environment.
AB - Preparation, characterization, and properties of a cyano bridged complex containing the Ru3(μ3-O) cores, [{Ru3(μ3-O) (μ-CH3COO)6(py)2}2(μ-CN)](PF6) ([1]PF6) (py = pyridine), are reported and compared with the properties of [{Ru3(μ3-O)(μ-CH3COO)6(py)2}(μ-CN){Ru3(μ3-O)(μ-CH3COO)6(py)(CO)}] (2). The cyclic voltammogram of [1]+ in 0.1 M (n-Bu)4NPF6-CH2Cl2 solution with an Ag/AgCl reference electrode showed a series of redox waves assigned to the processes Ru3II,II,III/Ru3II,III,III (-1.70 V, -1.52 V), Ru3II,III,III/Ru3III,III,III (-0.37 V, -0.19 V), Ru3III,III,III/Ru3III,III,IV (+1.08 V), and Ru3III,III,IV/Ru3III,IV,IV (+2.03 V). Upon bridge formation the redox waves of the C-bonded Ru3 moiety of [1]+ stay at the similar potential region to those of Ru3(μ3-O)(μ-CH3COO)6(py)2(CN) (3) with a unidentate CN-, so that the enhancement of the π-back donation does not operate, indicating that the Ru3O core is not a good π-donor. Complex 2 showed five redox waves for the processes Ru3II,II,III/Ru3II,III,III (-1.15 V), Ru3II,III,III/Ru3III,III,III (-0.21 V, +0.55 V), and Ru3III,III,III/Ru3III,III,IV (+1.05 V, +1.35 V). The redox potential (-1.15 V) of the Ru3II,II,III/Ru3II,III,III process of the Ru3(py) (CO) unit in 2 showed a negative shift in comparison to that (-0.84 V) of [Ru3II,III,III(μ3-O) (μ-CH3COO)6(py)2(CO)]. The infrared spectroelectrochemistry of [1]+ and 2 in 0.1 M n-Bu4NPF6-CH2Cl2 solutions revealed that the frequencies of the stretching vibration ν(CN) of the cyanide increased with the increase in the isovalent oxidation states of [1]+ but those in the Ru3O-based mixed-valence states, Ru3II,III,III-Ru3III,III,III, and Ru3III,III,III-Ru3III,III,IV, were significantly smaller, which was possibly due to the effective electronic coupling through the CN- bridge between the two Ru3 units with different oxidation states. In contrast, such coupling was not observed for 2 that has two Ru3 units with significantly different ligand environment.
KW - Cyanide ligand
KW - Infrared spectroelectrochemistry
KW - Oxo-centered triruthenium clusters
KW - Redox property
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U2 - 10.1016/j.jorganchem.2015.07.032
DO - 10.1016/j.jorganchem.2015.07.032
M3 - Article
AN - SCOPUS:84938900390
VL - 797
SP - 29
EP - 36
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
SN - 0022-328X
ER -