Ferrocene-anthraquinone

Fig. 4 Ferrocene-, anthraquinone- and ruthenium-derivitized electrochemical nucleoside triphosphates (electrotides) compatible with enzymatic incorporation into nucleic acids. Examples include a Fcl-UTP (adapted from [184]), b Aql-UTP (adapted from [184]), c Fcl-acyUTP (adapted from [185]), d ferrocene-acycloATP (adapted from [278]), e Fc2-dUTP (adapted from [181]), f Fcl-dUTP (adapted from [181]), g Aql-dCTP (adapted from [185]) and h dRuTP (adapted from [188])...

A more remarkable elongation of the CS lifetime was attained by complex formation of yttrium triflate [Y(OTf)3] with the CS state in photoinduced ET of a ferrocene-anthraquinone (Ec AQ) dyad (53). Photoexcitation of the AQ moiety in Ec AQ in deaerated PhCN with femtosecond (150 fs width) laser light results in appearance of the absorption bands 420 and 600 run at 500 fs, as shown in Eig. 14(a) (53). The absorption bands 420 and 600 nm, which are assigned to AQ by comparison with the absorption spectrum of AQ produced by the chemical reduction of AQ with naphthalene radical anion (53). The decay process obeys first-order kinetics with the lifetime of 12 ps [Eig. um. 

Scheme 7. Photodynamics of a ferrocene-anthraquinone dyad (Fc—AQ) (a) in the absence and (h) in the presence of Y(OTf)3 (53).

Table 3.4 Redox Potentials of Ferrocene-Anthraquinone Complexes and Their Protonated Species in 0.1 mol dm Bu4NC104-CH2Cl2 ...

Ethyttylene-Bridged Ferrocene-Anthraquinone (FcAq) Complexes 139... 

II. ETHYNYLENE-BRIDGED FERROCENE-ANTHRAQUINONE (FcAq) COMPLEXES... 

Various redox functionalities have been appended to NP cores via thiolated redox molecules, place exchange reactions, and postfunctionalization of a MPC through amide15 or ester-forming reactions.16 The redox moieties include ferrocene,17 biferrocene, phenol, nitrobenzene, and anthraquinone, which commonly are synthesized using a gold core composition. The observed voltammetry of these redox-active units tend to exhibit similar electrochemical potentials to their free... 

Fischer from tetrahydroindcne [253). In a similar manner, we obtained ferrocene analogs of anthronc and anthraquinone from ferrocene and phthalic anhydride. 

The deprotonated form, 1-FcAq, shows reversible two-step 1 e reduction at = -1.26 and -1.71 V versus ferrocenium/ferrocene (Fc /Fc) derived from the anthraquinone moiety, and reversible 1 e" oxidation at = 0.22 V due to the fer-rocenyl moiety in BU4NCIO4-CH2CI2 (Table 3.4). The first reduction potential shifts dramatically in the positive direction to E = -0.06 V, and the oxidation potential shifts moderately in the positive direction to E = 0.33 V in the protonation product, [1-FvAqH], whereas the second reduction potential is little changed. These results correspond to the structural changes in both ferrocenyl and anthraquinone moieties by protonation. 

In the paper [74] oxidation of ferrocene and anthracene in acetonitrile and dichloromethane was successfully studied using the NPV technique at 5 pm Pt disc microelectrodes. The pulse widths were very short (5 to 20 ps) combined with the waiting times of duration 25 ps. Besides NPV also RPV has been applied. The resulting NP and RP waves for the oxidation of 9,10-anthraquinone are demonstrated in Fig. 28. The model of quasi-reversible charge transfer was fitted and parameters of both processes (k , and E1/2) were estimated. The results show that NP and RP voltammetric experiments retain the advantages over fast CV method even at pulse times as short as 5 ps. They provide effective discrimination against the double-layer charging current as well. 

Consider the following example. Figure 9.27 shows a CV recorded on an n-Si electrode immersed in acetonitrile with two redox couples anthraquinone and its monoanion (AQ/AQ ) and ferrocene/ferrocenium (Fe(Cp)2/Fe(Cp)2 ). In this experiment, care was taken in the experimental set-up so that once the electrode was introduced into the cell, it was not further exposed to the external atmosphere. Thus, effects due to surface oxidation... 

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