1‘-(Diphenylphosphino)ferrocenecarboxylic Acid and Its P-Oxide and Methyl Ester: Synthesis, Characterization, Crystal Structure, and Electrochemistry

• DOI: 10.1021/om950528q
• Publication Date: 2002-07-26T05:01:06Z
• Authors: Jaroslav Podlaha; Petr Štěpnička; Jiří Ludvík; Ivana Císařová
• Keywords: Phosphine oxide

The ferrocene derivative (η5-C5H4PPh2)Fe(η5-C5H4COOH) (3), a potential hybrid phosphine ligand with heteroannular soft and hard donor groups, was synthesized in 71% yield from 1-phenyl-1-phospha[1]ferrocenophane by ring opening phenyllithium, followed reaction carbon dioxide acidification. Oxidation of 3 hydrogen peroxide its esterification diazomethane provided the derivatives, oxide 4 methyl ester 5, respectively. new compounds were characterized IR, UV/vis, MS, NMR spectroscopy, degenerate 1H spectra being assigned aid selective 1H{1H} decoupling, 1H,1H-COSY, 13C HMQC, nJ(P,C) APT. solid-state structures 3−5 determined single-crystal X-ray diffraction. Voltammetric measurements related monosubstituted derivatives acetonitrile revealed that phosphines are first oxidized to corresponding ferrocenium which then subject intramolecular electron transfer group iron, resulting species immediately stabilized further electrochemical and/or chemical oxidation give oxides. second independent process is reversible these ferrocene/phosphine oxides ferrocenium/phosphine There processes associated irreversible carboxyl group.