Redox-active macrocyles designed for direct attachment to electrode surfaces

Gokel

1996

J. Org. Chem.

Self Cite

Electrospray ionization mass spectrometry (ESI-MS) was used to probe multiple cation complexation by C(12)H(25)(CH(2))(12)(CH(2))(12)C(12)H(25), 2, and <18N>CH(2)C(6)H(4)CH(2), 3. Complexation of two cations (2Na(+), 2 K(+), or Na(+) and K(+)) by 3 and three cations by 2 (3 Na(+), 3 K(+), and mixtures) as well as mixed proton-metallic cation complexes of both were observed. The K(+)/Na(+) cation-binding selectivity of 18-crown-6 was studied by ESI-MS of a methanol solution, and the selectivity profile was favorably compared with data obtained previously by ion-selective electrode techniques in the same solvent.

Section: Resultsmentioning

confidence: 99%

Correlation of Solution and Gas Phase Complexation Assessed by Electrospray Ionization Mass Spectrometry: Application to One-, Two-, and Three-Ring Macrocycles

Gokel

1996

J. Org. Chem.

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“…First, compound 6 or 7 was prepared by the condensation of 4-aminophenol or 6-amino-1-hexanol with 5 . The purified 6 or 7 was then reacted with chlorocarbonylferrocene through an esterification reaction. After purification by chromatography on silica gel, triads 2 and 3 were obtained as red solids in yields of 56 and 45%, respectively.…”

Section: Resultsmentioning

confidence: 99%

Effects of Photoinduced Electron Transfer on the Rational Design of Molecular Fluorescence Switch

Zhang

et al. 2009

J. Phys. Chem. C

Aiming at exploring the relationship between the spacer and fluorescence switch properties, we synthesized a series of new photoactive triads, in which one perylenetetracarboxylic diimide unit acting as the electron acceptor was attached to two ferrocene moieties through different spacers. This kind of donor-spacer-acceptor structure allows for tuning one of the key factors that governs photoinduced electron transfer, the distance between the electron donor and acceptor units. The excited-state electron-transfer processes were monitored by both steady-state and time-resolved emission as well as transient absorption techniques. It was found that fluorescence intensity of the solution of all triads 1-3 can be reversibly modulated by the electrochemical oxidation and reduction sequentially. More importantly, as the length of the spacer between the donor and acceptor increases, the background fluorescence increased proportionally, but the contrast ratio of the fluorescence decreases. Together these two factors determine the assay sensitivity, and therefore this work is helpful to provide a basis for the rational design of fluorescence switch by optimizing these factors above.

Redox-Switched Amphiphiles: Oxidized Ferrocene Derivatives Form Stable Vesicles When Either One or Two Alkyl Tails Are Present

Gokel

1997

J. Phys. Org. Chem.

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Thirty ferrocene derivatives were prepared and their ability to form vesicles in aqueous solution when oxidized was assessed. The compounds included alkyl ferrocenylmethyl ether derivatives of the form C 10 H 9 FeCH 2 OR in which R = octyl, dodecyl, tetradecyl, hexadecyl, octadecyl and eicosanyl. One single-tailed amine derivative, C 10 H 9 FeCH 2 NR 2 , R = octadecyl, was studied. Alkylferrocene derivatives had the form C 10 H 9 FeR in which R = butyl, decyl, tetradecyl, hexadecyl, octadecyl, eicosanyl and docosanyl. Sixteen symmetrical 1,1Ј-disubstituted ferrocenes were also studied. Three ethers were of the form C 10 H 8 Fe-1,1Ј-(CH 2 OR), 2 , R = tetradecyl, hexadecyl and octadecyl. Four corresponding dialkyl derivatives of the form C 10 H 8 Fe-1,1Ј-R 2 , R = decyl, tetradecyl, hexadecyl and octadecyl, were assessed. Finally, a range of 1,1Ј-disubstituted ferrocene derivatives were analyzed. These all had the form C 10 H 8 Fe-1,1Ј-(COR) 2 , for which R has the following identities: octyl, tridecyl, pentadecyl and heptadecyl (ketones); heptadecyloxy, 3-cholesteryl and 3-cholestanyl (esters); and two amides, R = NHC 18 H 37 and N(C 18 H 37 ) 2 . The alkyl and ether derivatives could be readily oxidized and formed vesicular aggregates upon sonication. The ketones, esters and amides could be oxidized but the ferricenium derivatives did not form stable aggregates. An interesting observation is that the aggregates formed were vesicular whether the ferrocene derivative had one or two alkyl tails.