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|6.1 Synthesis of the Organic Ligands| layer thickness 0.25 µm) with nitrogen as carrier gas (purity 99.999%) an oven temperature of 70°C, a flow rate of 22.5 ml/min, a detector temp. of 220°C, and a pressure of 102.1 kPa were used. The GC was calibrated by mixing different volumes of pure hydrogen (0-100%) together with nitrogen into a Schlenk vessel. The obtained signal (retention time for H 2 , t R = 1.95 min) was plotted against the calibration curve and multiplied accordingly to receive the total produced hydrogen content in the headspace. Irradiation experiments and hydrogen measurements were repeated several times for each reaction time (between 2 and 12 h) and catalyst concentration. Used Chemicals: All chemicals were reagent grade and were used without any further purification. Where necessary all manipulations were carried out by using Schlenk techniques under argon atmosphere. Prior to use dichloromethane was distilled over CaH 2 . Acetonitrile was dried and distilled over mole sieves A 4, methanol was dried and distilled over magnesium. THF and toluene and triethylamine were dried over KOH and distilled over Na/benzophenone. Prepared Chemicals The following chemicals were prepared according to literature procedures: [Ru(tbbpy) 2 Cl 2 ] [120] , [Ru(tbbpy) 3 ][PF 6 ] [120] 2 , [Ru(tbbpy) 2 (5-chloro-1,10-phenanthroline)][PF 6 ] [116] 2 , 4,4’-ditertbuthyl- 2,2’-bipyridine [204, 205] , 1,10-Phenanthrolin-5,6-dione [206] , [Ru(COD)Cl 2 ] [128] , 3,8-dibromo-1,10- phenanthrolin-5,6-dione [126] , bisbromethyldurene [207] , NiCl 2 (PPh 3 ) [208] 2 , [Pd(Cl) 2 (ACN) 2 ] [208] , [Mo(CO) 5 (thf)] [183] , 6.1 Synthesis of the Organic Ligands 6.1.1 Bromination of Phenanthrolines - method L1 To a round bottom flask, charged with 4.0 g of the phenanthroline derivate, 30 ml of fuming sulfuric acid (65%) were added with cooling (0°C). Then a big stir bar was carefully added to the mixture and the neck of the flask was closed with a watch glass. After stirring complete dissolution (∼2 hours stirring at 10°C) of the phenanthroline an the desired amount of bromine was added to the solution in one portion and the mixture was stirred until the brown color of the bromine |197|
|6.1 Synthesis of the Organic Ligands| disappeared. Heating of the mixture (60°C) may accelerate the reaction. After the reaction time the mixture was poured onto 200 ml of ice and was neutralized (pH 7) with ammonia. The formed precipitate was extracted with chloroform. Subsequently, the combined organic layers were dried over Na 2 SO 4 and the solvent was removed under vacuum. Then, the crude was dissolved in hot toluene and insoluble impurities were filtered off. After removal of the solvent purification was achieved by recrystallization from (ethanol, chloroform or ether/methylene chloride). Drying in high-vacuum yielded the desired brominated product. 6.1.2 1-Substitution of 1H-Imidazoles - method L2 Under argon atmosphere the desired amount of the desired 1H-imidazole (∼1.5 g) and 1.1 equivalent of sodium hydride (60% in paraffin) were suspended in 50 ml of dry DMF. After stirring and/or sonicating for several minuted the solids were completely reacted and no further gas evolution or sold material was observed. Then one equivalent of halogenated compound was added and the solution. Stirring for several hours at room temperature yielded a tinted solution. After the reaction time, the solvent was removed completely under vacuum and the residue was redissolved in chloroform and washed with water. The combined organic phases were dried over Na 2 SO 4 . After removal of the organic solvent the crude product was purified by column chromatography using chloroform and silica gel 60 as phase system. 6.1.3 3-Substitution of 1-Substituted 1H-Imidazoes - method L3 One equivalent (∼2.0 g) of the desired 1-substituted 1H-imidazoe was dissolved in a mixture of DMF and an excess of the halogenated compound. The solution was heated to 60-120°C for one to sixteen hours to form a viscous yellow precipitate, which was collected after cooling and was washed with toluene or petrol ether and diethyl ether. The crude product was purified by recrystallization from hot toluene with a small amount of methanol to yield the 1,3-substituted 1H-imidazolium halide as cream colored solid. A combination of method L2 and method L3 is possible for the prepatation of 1,3-homosubstituted 1H-imidazolium halides without intermediate workup. |198|
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Development of Novel Catalysts for
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Diese Arbeit entstand auf Anregung
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Den Arbeisgruppen von Prof. Dr. U.
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Contents 1 Introduction 1 1.1 Fossi
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|Contents| 6 Experimental Section 1
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|1 Introduction| 1 Introduction The
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|1.1 Fossil Fuels and Nuclear Power
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|1.2 Renewable Fuels| of natural ga
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|1.3 Energy Transformation and Stor
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|1.4 Solar Energy Conversion| A fra
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|1.5 Photosynthesis| Figure 9: Mole
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|1.6 Photocatalyzed Reactions| 2 NA
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|1.6 Photocatalyzed Reactions| (1)
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|1.7 Mimicking Photosynthesis| So t
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|1.8 Formalisms of Photocatalytic S
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|1.9 Multicomponent Systems from Fu
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|1.10 Intramolecular Photoredoxcata
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|2 Scope of the Thesis| motifs with
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|3.1 Brominated Phenanthrolines - A
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|3.2 Bisphenanthroline: A Suitable
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f f f f f f |3.2 Bisphenanthroline:
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|3.3 NN-NHC-Ligand bbip: Toward Sec
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Page 158 and 159: |3.3 NN-NHC-Ligand bbip: Toward Sec
Page 170 and 171: |3.4 Outlook, Exploratory Investiga
Page 185 and 186: |4 Summary| 4 Summary Against the b
Page 187 and 188: |4 Summary| The resulting complexes
Page 189 and 190: |4 Summary| 10 [TEA] + TEA visible
Page 191 and 192: |4 Summary| absorption between 430
Page 193 and 194: |4 Summary| additional NN- and NHC-
Page 195 and 196: |5 Zusammenfassung| Die Herstellung
Page 197 and 198: |5 Zusammenfassung| phenphen und Ru
Page 199 and 200: |5 Zusammenfassung| Fragment tragen
Page 201 and 202: |5 Zusammenfassung| [TEA] + TEA vis
Page 203 and 204: |5 Zusammenfassung| In einer abschl
Page 205 and 206: |6 Experimental Section| Spectroele
Page 207: |6 Experimental Section| 1.3648 was
Page 211 and 212: |6.1 Synthesis of the Organic Ligan
Page 223 and 224: |6.2 Synthesis of the Metal Complex
Page 249 and 250: |7 Appendix| 7 Appendix dd ddd DEI
Page 251 and 252: |7 Appendix| Ru(tpphz)Os [Ru(bpy) 2
Page 253 and 254: |References| [26] M. Chanon, M. Sch
Page 255 and 256: |References| [81] S. Tschierlei, M.
Page 257 and 258: |References| [138] L. Pazderski, J.
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|References| [194] C. Liu, J. Li, B
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Selbstständigkeitserklärung: Ich
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