The compds. Fe(CO)3(dRpf)n+, n=0, 1, 2 and dRpf=1,1'-bis(dicyclohexylphosphino)ferrocene (1n+) or 1,1'-bis(diisopropylphosphino)ferrocene (2n+), were obtained as two-step reversible redox systems by photolytic and redox reactions. The iron-iron distance decreases from about 4 \AA to about 3 \AA on oxidn., which takes place primarily at the tricarbonyliron moiety. Whereas ferrocene oxidn. is calcd. to occur only in excited states, the near IR absorptions of the mixed-valent monocations are due to an unprecedented \dqinverse\dq inter-valence charge transfer from the electron-rich iron(II) in the ferrocene backbone to the electron-deficient tricarbonyliron(I). Protonation of complex 1 results in the formation of the structurally characterized hydride 1HBF4, which reacts with acetone to form the dication, 12+, and isopropanol. While the hydride 2HBF4 was found to be unstable, protonation of 2 in acetone resulted in the clean formation of 22+, formally a hydrogen transfer. on SciFinder(R)
%0 Journal Article
%1 Ringenberg.2017b
%A Ringenberg, Mark R.
%A Schwilk, Max
%A Wittkamp, Florian
%A Apfel, Ulf-Peter
%A Kaim, Wolfgang.
%D 2017
%J Chemistry - A European Journal
%K bond calcn;mol carbonyl charge complex crystal ferrocenyl iron mol optimized prepn;mixed redox spectroelectrochem structure transfer valent
%N 8
%P 1770--1774
%R 10.1002/chem.201605527
%T Organometallic Fe-Fe Interactions: Beyond Common Metal-Metal Bonds and Inverse Mixed-Valent Charge Transfer
%V 23
%X The compds. Fe(CO)3(dRpf)n+, n=0, 1, 2 and dRpf=1,1'-bis(dicyclohexylphosphino)ferrocene (1n+) or 1,1'-bis(diisopropylphosphino)ferrocene (2n+), were obtained as two-step reversible redox systems by photolytic and redox reactions. The iron-iron distance decreases from about 4 \AA to about 3 \AA on oxidn., which takes place primarily at the tricarbonyliron moiety. Whereas ferrocene oxidn. is calcd. to occur only in excited states, the near IR absorptions of the mixed-valent monocations are due to an unprecedented \dqinverse\dq inter-valence charge transfer from the electron-rich iron(II) in the ferrocene backbone to the electron-deficient tricarbonyliron(I). Protonation of complex 1 results in the formation of the structurally characterized hydride 1HBF4, which reacts with acetone to form the dication, 12+, and isopropanol. While the hydride 2HBF4 was found to be unstable, protonation of 2 in acetone resulted in the clean formation of 22+, formally a hydrogen transfer. on SciFinder(R)
@article{Ringenberg.2017b,
abstract = {The compds. [Fe(CO)3(dRpf)]n+, n=0, 1, 2 and dRpf=1,1'-bis(dicyclohexylphosphino)ferrocene ([1]n+) or 1,1'-bis(diisopropylphosphino)ferrocene ([2]n+), were obtained as two-step reversible redox systems by photolytic and redox reactions. The iron-iron distance decreases from about 4 {\AA} to about 3 {\AA} on oxidn., which takes place primarily at the tricarbonyliron moiety. Whereas ferrocene oxidn. is calcd. to occur only in excited states, the near IR absorptions of the mixed-valent monocations are due to an unprecedented {\dq}inverse{\dq} inter-valence charge transfer from the electron-rich iron(II) in the ferrocene backbone to the electron-deficient tricarbonyliron(I). Protonation of complex 1 results in the formation of the structurally characterized hydride [1H]BF4, which reacts with acetone to form the dication, 12+, and isopropanol. While the hydride [2H]BF4 was found to be unstable, protonation of 2 in acetone resulted in the clean formation of 22+, formally a hydrogen transfer. [on SciFinder(R)]},
added-at = {2019-07-15T13:41:23.000+0200},
author = {Ringenberg, Mark R. and Schwilk, Max and Wittkamp, Florian and Apfel, Ulf-Peter and Kaim, Wolfgang.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2bd05ce7854cfbe6edbb11965719c7ec6/b_schwederski},
doi = {10.1002/chem.201605527},
interhash = {2ba709315039dcf103bd285b7fcf0ebf},
intrahash = {bd05ce7854cfbe6edbb11965719c7ec6},
issn = {0947-6539},
journal = {Chemistry - A European Journal},
keywords = {bond calcn;mol carbonyl charge complex crystal ferrocenyl iron mol optimized prepn;mixed redox spectroelectrochem structure transfer valent},
number = 8,
pages = {1770--1774},
timestamp = {2019-07-15T11:42:10.000+0200},
title = {Organometallic Fe-Fe Interactions: Beyond Common Metal-Metal Bonds and Inverse Mixed-Valent Charge Transfer},
volume = 23,
year = 2017
}
