Mechanistic investigation of the electrochemical reduction of Cp2TiX2

被引:66
作者
Enemærke, RJ [1 ]
Larsen, J [1 ]
Skrydstrup, T [1 ]
Daasbjerg, K [1 ]
机构
[1] Aarhus Univ, Dept Chem, DK-8000 Aarhus C, Denmark
关键词
D O I
10.1021/om034360h
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The mechanism for the electrochemical reduction of titanocene dihalides, CP2TiX2 (X = Cl, Br, I), in tetrahydrofuran has been described successfully using a common mesh scheme. On the basis of simulations of recorded cyclic voltammograms it has been possible to evaluate a number of thermodynamic and kinetic parameters for the species involved: i.e., CP2TiX2-, (CP2TiX)(2), CP2TiX, and CP2Ti+. In general, the standard potentials of the oxidized titanium-based species increase (i.e. become less negative) in the orders CP2TiX2, (CP(2)Tix)(2)(+), CP2TiX+, CpTi2+ and X = Cl, Br, I. From the extracted data pertaining to electrochemically reduced solutions Of CP2TiX2, it becomes evident that while CP2TiX2- is the major constituent for X = Cl, CP2TiX and (CP2TiX)(2) are the main species in the cases of X = Br, I. The presence Of (CP2TiX)(2) is surprising, as the solvent tetrahydrofuran was believed to be capable of breaking the weak dimeric structure. Kinetic investigations of the reactions between electrochemically reduced solutions Of CP2TiX2 and benzyl chloride show that the reactive species are CP2TiX and (CP2TiX)(2), with almost no contribution from CP2TiX2-, even in the case of X = Cl.
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页码:1866 / 1874
页数:9
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