Structures and Redox Reactivities of Copper Complexes of (2-Pyridyl)alkylamine Ligands. Effects of the Alkyl Linker Chain Length
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- 作者：Takao Osako ; Yoshiki Ueno ; Yoshimitsu Tachi ; and Shinobu Itoh
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：December 1, 2003
- 年：2003
- 卷：42
- 期：24
- 页码：8087 - 8097
- 全文大小：192K
- 年卷期：v.42,no.24(December 1, 2003)
- ISSN：1520-510X
文摘
Ligand effects on the structures and redox reactivities of copper complexes have been examined using (2-pyridyl)alkylamine derivatives as the supporting ligands, where particular attention has been focused on the effects of thealkyl linker chain length connecting the tertiary amine nitrogen atom and the pyridine nucleus: N-CH2-Py (Pym)vs N-CH2CH2-Py (Pye). X-ray crystallographic analysis of the copper(I) complex of tridentate ligand PheLPym2 [N,N-di(2-pyridylmethyl)-2-phenylethylamine] (complex 1) has demonstrated that it possesses a trigonal pyramidal geometryin which a d-
interaction with an 
1-binding mode exists between the metal ion and one of the ortho carbons ofthe phenyl ring of the ligand side arm (phenethyl). The result shows sharp contrast to the d- interaction with an2-binding mode existing in the copper(I) complex of PheLPye2 {N,N-di[2-(2-pyridyl)ethyl]-2-phenethylamine} (complex2). Such a d- interaction has been shown to affect the stability of the copper(I) complex in CH2Cl2. Oxygenationof copper(I) complex 1 supported by PheLPym2 produces a bis(
-oxo)dicopper(III) complex, also being in sharpcontrast to the case of the copper(I) complex 2 with ligand PheLPye2, which preferentially affords a (-2:2-peroxo)dicopper(II) complex in the reaction with O2. Such an effect of the alkyl linker chain length of the metal binding sitehas also been found to operate in the RSSR (disulfide)/2RS- (thiolate) redox system. Namely, ligand S2,RLPym1(di{2-[(alkyl)(2-pyridinylmethyl)amino]ethyl} disulfide) with the methylene linker group (Pym) induced the reductivedisulfide bond cleavage in the reaction with copper(I) ion to give a bis(-thiolato)dicopper(II) complex, while theligand with the ethylene linker group (Pye), S2,BnLPye1 (di{2-[(benzyl)(2-(2-pyridinyl)ethyl)amino]ethyl} disulfide), gavea disulfide-dicopper(I) complex. These ligand effects in the Cu2-O2 and Cu2-S2 systems have been discussed bytaking into account the difference in electron-donor ability of the pyridine nucleus between the Pym and Pye ligandsystems.
interaction with an 1-binding mode exists between the metal ion and one of the ortho carbons ofthe phenyl ring of the ligand side arm (phenethyl). The result shows sharp contrast to the d- interaction with an2-binding mode existing in the copper(I) complex of PheLPye2 {N,N-di[2-(2-pyridyl)ethyl]-2-phenethylamine} (complex2). Such a d- interaction has been shown to affect the stability of the copper(I) complex in CH2Cl2. Oxygenationof copper(I) complex 1 supported by PheLPym2 produces a bis(-oxo)dicopper(III) complex, also being in sharpcontrast to the case of the copper(I) complex 2 with ligand PheLPye2, which preferentially affords a (-2:2-peroxo)dicopper(II) complex in the reaction with O2. Such an effect of the alkyl linker chain length of the metal binding sitehas also been found to operate in the RSSR (disulfide)/2RS- (thiolate) redox system. Namely, ligand S2,RLPym1(di{2-[(alkyl)(2-pyridinylmethyl)amino]ethyl} disulfide) with the methylene linker group (Pym) induced the reductivedisulfide bond cleavage in the reaction with copper(I) ion to give a bis(-thiolato)dicopper(II) complex, while theligand with the ethylene linker group (Pye), S2,BnLPye1 (di{2-[(benzyl)(2-(2-pyridinyl)ethyl)amino]ethyl} disulfide), gavea disulfide-dicopper(I) complex. These ligand effects in the Cu2-O2 and Cu2-S2 systems have been discussed bytaking into account the difference in electron-donor ability of the pyridine nucleus between the Pym and Pye ligandsystems.