Ferrocenyloxysilanes: Synthesis, characterization and electrochemical investigations

P. Frenzel, S. W. Lehrich, M. Korb, A. Hildebrandt, H. Lang

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6 Citations (Scopus)

Abstract

A series of ferrocenyloxysilanes of type Si(OFc)(n)R4-n (Fc - Fe(eta(5)-C5H4)(eta(5)-C5H5); R - Me: 2, n = 1; 3, n = 2; 4, n = 3; 5, n = 4. R = Ph: 6, n = 2) and 1,3-dioxa-2-dimethylsilae[ 3] ferrocenophane (8) have been synthesized by the reaction of FcOH (1) or Fe(eta(5)-C5H4OH) 2 (7) with the respective chlorosilanes SiClnR4-n. Treatment of 6 with Ag[ B(C6F5)(4)].Et2O resulted in the formation of [ Fe(eta(4)eC(5)H(4)(=O))(eta(5) -C5H5)][ B(C6F5)(4)] (9). The molecular structures of 1-6, 8 and 9 in the solid state are reported. The electrochemical behavior of 2-6 and 8 was investigated by cyclic (CV) and square wave voltammetry. Ferrocenyloxysilane 3 shows two separated redox events at E1 degrees' = -125 mV (Delta E-p =62 mV) and E-2 degrees' = 80 mV (Delta Ep = 60 mV) during the first three cycles. However, in multi-cyclic experiments it decomposes. This differs from 4 and 5 because these compounds decompose more rapidly. Compared to 3, compound 6 (E-1 degrees', = -125 mV (Delta Ep = 59 mV), E-2 degrees' = 55 mV (Delta Ep = 62 mV)) in which Ph units are present is more stable towards electrochemical oxidation. The electron-donating OSiMe3 group in 2 leads to a significant cathodic shift of the redox potential (E degrees' = -165 mV) as compared with FcH. In contrast, ferrocenophane 8 possesses a reversible redox event at E degrees' = 10 mV (Delta Ep = 66 mV). Exemplarily, spectroelectrochemical UV-Vis/NIR studies were carried out on 6 indicating significant electrostatic interaction among the two ferrocenyloxy groups as oxidation progresses. (C) 2017 Elsevier B. V. All rights reserved.

Original languageEnglish
Pages (from-to)98-106
Number of pages9
JournalJournal of Organometallic Chemistry
Volume845
DOIs
Publication statusPublished - 15 Sep 2017
Externally publishedYes

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