FU Berlin Digitale Dissertation
Marc Skupin : Synthesis of Diamido-Bolaamphiphiles and Synkinesis of porphyrin-containing Gaps in Monolayers of Gold Synthese von Diamido-Bolaamphiphilen und Synkinese von porphyrinhaltigen Lücken in Monoschichten auf Gold
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Abstract A series of olefinic hydrosulfide-bolaamphiphiles was synthesized to produce rigid monolayers with nanometer gaps on gold substrates, which can be functionalized in aqueous media. They either contained an activated carbon-carbon double bond ( Michael-bolaamphiphile ) for the Michael-Addition or an electron-rich double bond for bromination ( Alken-bolaamphiphile ). In order to produce rigid membranes an octacarboxylic acid porphyrin was fixed on gold by self-assembly from water at pH 12. The second self-assembly procedure step, the fixation of the bolaamphiphiles, was effected from a chloroform solution. A monolayer with a thickness of 20-25 Å, containing gaps of a 20 Å diameter, was obtained. Further the porous membranes were examined by a laser spectrometer for porphyrin fluorescence. There was no apparent difference in fluorescence intensity before and after the second self-assembly procedure. After addition of a copper-pyridinium porphyrin, this fluorescence was extinguished quantitatively. If the double bond of Michael-bola was aminated by means of a methylamine the Copper-pyridinium porphyrin could not enter the gap. Negatively-charged porphyrins were fixed in the gap by methylammonium groups, as shown by UV/Vis spectroscopy and on the other hand by the interruption of the ion current of [Fe(CN)6]4-from the bulk water solution. The second porphyrin was localized at a distance of 20 Å from the first one and acted as cover for the gap. If the pH-value was increased to 12, the methylammonium ions were neutralized and the "cover-porphyrin" dissociated in the bulk water volume. In this case Ferricyanide ions had again free access to the electrode. This closing and opening procedure is reversible and can be repeated several times. An analogous amination from aqueous medium by successive treatmeant with sodium hypobromite and methylamine was used for the Alken-bola. We thus succeeded to produce not covolent porphyrin-heterodimers ( "bottom"- and "cover-porphyrin" ) with a long distance (8 and 20 Å resp.) reproducibly. In first attempts to transfer the systems discribed above from planar electrodes to colloidal particles in volume water, gold colloids were applied. In order to increase the solubility of colloids in water, a bolaamphiphile was synthesized, which contained a gluconamide- instead of a methyl end group as done before in the synthesis of the alken-bola. The gold particles with a comparatively high mass are soluble with the Gluconamide-bola in aqueous solution permanently.

Table of Contents Download the whole PhDthesis as a zip-tar file or as zip-File For download in PDF format click the chapter title Inhaltsverzeichnis 0.Deckblatt und Danksagung Gutachter      1.Einleitung      1 2. Synthese und Charakterisierung          8 2.1 Synthese des Michael-Bolaamphiphils (8)          8 2.2 Synthese des Alken-Bolaamphiphils (17)        16 2.3 Synthese des Octyl-Bolaamphiphils (21)        25 2.4 Synthese des Gluconamid-Bolaamphiphils (26)        28 2.5 Funktionalisierung der Bolaamphiphile        31 2.5.1 Funktionalisierung des Michael-Bolaamphiphils (8)        31 2.5.2 Funktionalisierung des Alken-Bolaamphiphils (17)        34 2.6 Verwendete Porphyrine        35 3. Charakterisierungsmethoden        38 3.1 UV / Vis - Spektroskopie        38 3.2 Fluoreszenzspektroskopie        40 3.3 Fluoreszenz auf Metalloberflächen        41 3.4 Cyclische Voltammetrie (CV)        42 4. Fluoreszenzspektroskopie        48 4.1 Allgemeine Versuchsbedingungen und Fluoreszenzspektren des         48 Octacarbonsäureporphyrins (32)      4.2 Fluoreszenzlöschungsexperimente ohne und mit "Zaun"         51 4.3 Blockieren der Lücken durch trans-1,2-Cyclohexandiol        54 4.4 Einfluß der Methylamin-Michaeladdition        55 5. Cyclische Voltammetrie (CV)       58 5.1 Allgemeine Versuchsbedingungen und Cyclovolammogramm des         58 Octacarbonsäureporphyrins (32)      5.2 Cyclovoltammogramm des Michael-Bolaamphiphils (8)        59 5.3 Cyclovoltammogramme der Porphyrinlücken        60 5.4 Lückenverschluß durch Tyrosin        63 5.5 System mit dem Michael-Bolaamphiphil (8)        65 5.5.1 Funktionalisierung und Verschluß der Lücken        65 5.5.2 Nachweis der Porphyrine auf der Goldoberfläche durch       68 UV/ Vis-Spektroskopie      5.6 System mit dem Alken-Bolaamphiphil (17)      70 5.7 Diskussion      72  6. Modifikation der Lösungseigenschaften von Kolloiden        75 6.1 Ziel der Kolloidmodifikation und allgemeiner Überblick         75 6.2 Herstellung der "Citrat-Goldkolloide"        75 6.3 Modifikation der Kolloide mit dem Alken-Bolaamphiphil (17)        76 6.4 Modifikation Kolloide mit Octyl- und Gluconamid-Bolaamphiphilen        77  7. Zusammenfassung        80 7.1 Deutsche Zusammenfassung        80 7.2 English Conclusion        83  8. Experimenteller Teil        86 8.1 Meßgeräte und Hilfsmittel        86 8.2 Verwendete Abkürzungen und Symbole        88 8.3 Synthesevorschriften        89 8.4 Funktionalisierung der Bolaamphiphile in Lösung      113 8.5 Goldelektrodenmodifikation      116 8.6 Kolloidherstellung und Modifikation      117 9. Literaturverzeichnis      118

More Information:
Online available:	http://www.diss.fu-berlin.de/2001/205/indexe.html
Language of PhDThesis:	german
Keywords:	bolaamphiphil, porphyrin, colloid, membrane, monolayer
DNB-Sachgruppe:	30 Chemie
Date of disputation:	09-Oct-2001
PhDThesis from:	Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin
First Referee:	Prof. Dr. Jürgen-H. Fuhrhop
Second Referee:	Prof. Dr. Arnulf Dieter Schlüter
Contact (Author):	plata@chemie.fu-berlin.de
Contact (Advisor):	fuhrhop@chemie.fu-berlin.de
Date created:	19-Oct-2001
Date available:	24-Oct-2001

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