Electronic structure of various ferricenium systems as inferred from Raman, infrared, low-temperature electronic absorption, and electron paramagnetic resonance measurements

The synthesis and electrochemistry of 2,5-dimethylazaferrocenes with heteroaryl bridges

“…Upon oxidation these bands red-shift to 735, 697 and 570 nm. 15 + thus absorbs at lower energy than poly-2,5-bis-(2-thiophene)-1 0 ,2 0 ,3 0 ,4 0 ,5 0 -pentamethylazaferrocene (k max = 662 nm) [22] and parent ferrocenium (641 and 631 nm), but at similar energy as the 1,1 0 -dimethylferrocenium ion (711, 702 nm) [24]. Even under the conditions of spectroelectrochemistry, 15 + is only short-lived and is subject to polymerization upon which the radical cation bands disappear while a red film forms on the working electrode.…”

Solid‐Phase Synthesis of Chiral Modular Ferrocene‐Based Peptides

“…EPR spectroscopy [16] confirms the formation of the immobilised ferricinium cation as the typical axial pattern with g ʈ = 4.30 and g Ќ = 1.99 is observed. [17] Chemical reversibility is checked on-bead by re-reduction to the neutral peptides employing CoCp 2 as reductant and UV/Vis-spectrophotometric monitoring (disappearance of the 512 nm band of CoCp 2 and development of the 400 nm absorption band of [CoCp 2 ] + ). Reduction requires hours to be completed, probably because of the hydrophobic character of CoCp 2 and the hydrophilic nature of the Tentagel resin employed (Figure 5, bottom).…”

Terahertz vibrational spectra of metallocene

“…There are some opinions about the assignments of low-frequency fundamental modes. Based on Raman spectra, Duggan and Hendrickson [21] concluded that symmetric stretching x 4 , antisymmetric stretching x 11 , and antisymmetric ring tilt x 21 , correspond to 169, 451, and 515 cm À1 (5.07, 13.5, and 15.5 THz), respectively. In contrast, Phillips et al [19] reported that the 511-and 454-cm À1 bands correspond to x 11 and x 21 .…”