Sonochemistry of selected hydrocarbons, sulfur containing and nitrogen containing organic compounds in aqueous solutions and nonaqueous Liquids [Elektronische Ressource] / von Zhi-Lin Wu

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Informations

• Publié par: friedrich-schiller-universitat_jena
• Publié le: 01 janvier 2005
• Nombre de lectures: 26
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Sonochemistry of Selected Hydrocarbons, Sulfur-containing
and Nitrogen-containing Organic Compounds in Aqueous
Solutions and Nonaqueous Liquids

Dissertation
Zur Erlangung des akademischen Grades doctor rerum naturalium
(Dr. rer. nat.)






vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakultät der
Friedrich-Schiller-Universität Jena
von Dipl. Chem. (Umweltchemie) Zhi-Lin Wu
geboren am 30. Juli 1965 in Zhenjiang, Jiangsu Provinz von China.






















Gutachter:
1.
2.
Tag der öffentlichen Verteidigung:
I
Contents
1 Introduction...........................................................................................................1
2 Theoretical Part.....................................................................................................4
2.1 Ultrasound..............................................................................
2.2 Acoustic Cavitation................................................................................................4
2.3 Mechanisms and Sites of Sonochemical Reactions............................................... 6
2.3.1 Mechanisms of Sonochemical Reactions....................................................... 6
2.3.2 Sites of Sonochemical Reactions ................................... 8
2.4 Kinetics of Sonochemical Reactions ..................................................................... 9
2.5 Sonochemistry of Organic Compounds in Aqueous Solutions ........................... 10
2.5.1 Mechanisms and Reaction Sites of Aquasonolysis...................................... 10
2.5.2 Effects of Acoustic Frequency ..................................................................... 14
2.5.3 stic Power............................................................................ 16
2.5.4 Effects of the Bulk Liquid Temperature and Applied Pressure ................... 18
2.5.5 the Dissolved Gas ........................................................................ 20
2.5.6 Effects of Organic Solutes ....................................................... 22
2.5.7 Effects of pH Values of the Solutions.......................................................... 25
2.6 Sonochemistry of Organic Chemicals in Nonaqueous Liquids........................... 26
2.6.1 Roles of Vapor Pressures of Organic Liquids.............................................. 27
2.6.2 Ultrasonic Cleavage of Organic Liquids and Radical Reactions ................. 27
2.6.3 Sonoluminescence and Temperatures at Hot Spots in Organic Liquids ...... 29
2.6.4 Sonolytic Rates and Kinetics of Organic Liquids ........................................ 30
3 Experimental Part................................................................................................32
3.1 Chemicals.............................................................................
3.2 Ultrasound Devices and Operating Conditions ............................... 33 II
3.2.1 Ultrasound Setup for Aqueous Solutions..................................................... 33
3.2.2 Ultrasound Setup for Nonaqueous Solutions ............................................... 34
3.3 Ultrasonic Power Measurement...........................................................................35
3.4 Analysis...............................................................................................................36
3.4.1 Sampler........................................................................36
3.4.2 Gas Chromatography...................................................................................37
3.4.3 UV/Vis Analysis of DPPH........................................................................... 38
4 Results of Sonolyses of Volatile Organic Substrates in Aqueous Solutions....... 39
4.1 Aquasonolyses of Selected C H Hydrocarbons................................................. 39 6 X
4.1.1 Aquasonolytic Rate Constants of Selected Cyclic Hydrocarbons ............... 39
4.1.2 Aquasonolytic Rate Constants of Selected Aliphatic Hydrocarbons........... 40
4.1.3 Products of Aquasonolyses of Selected C H Hydrocarbons...................... 40 6 X
4.2 Formation of Benzene during Aquasonolyses of the Selected C H 6 X
Hydrocarbons ...................................................................................................... 47
4.2.1 Yield and Selectivity of Benzene during Aquasonolyses ............................ 47
4.2.2 Effect of the Initial Concentration on the Yield of Benzene........................ 49
4.2.3 Comparisons of Selectivity between Benzene and Other C Products 6
during the Aquasonolysis of 1,3-Cyclohexadiene ....................................... 49
4.3 Aquasonolyses of Thiophene and Its Derivatives................................................ 50
4.3.1 Aquasonolytic Rate Constants of Thiophene and Its Derivatives................ 51
4.3.2 Products from Aquasonolyses of Selected Thiophenes ............................... 52
4.4 Aquasonolyses of Thioethers............................................................................... 55
4.4.1 Aquasonolytic Rate Constants of Thioethers........................... 55
4.4.2 Products from Aquasonolyses of the Selected Thioethers........................... 56
4.5 Aquasonolyses of N-Heterocyclic Compounds................................................... 58
4.5.1 Aquasonolytic Rate Constants of the Selected N-Heterocycles .................. 59
4.5.2 Products from Aquasonolyses of the Selected N-Heterocycles................... 60
5 Results of Sonolyses of Volatile Organic Substrates in Nonaqueous
Liquids................................................................................................................. 61 III
5.1 Sonolyses of Aliphatic and Cyclic C H Hydrocarbons ..................................... 61 6 X
5.1.1 Sonolyses of the Selected C H Hydrocarbons at Normal Temperature..... 61 6 X
5.1.2 Sonolyses of the Selected Aliphatic C H Hydrocarbons at Low 6 X
Temperature ................................................................................................. 61
5.1.3 Sonolyses of the Selected Cyclic C H Hydrocarbons at Low 6 X
Temperature ................................................................. 67
5.2 Sonolytic Products of Selected Cyclic C H Hydrocarbons in Nonaqueous 6 X
Solutions.............................................................................................................. 71
5.2.1 Formation of Benzene during Sonolyses of Cyclohexene and
Cyclohexadiene in Organic Solvents ........................................................... 71
5.2.2 Secondary Reactions Occurring during Sonolyses of Cyclohexene and
Cyclohexadiene in Tetrachloroethylene....................... 73
5.2.3 Secondary Reactions Occurring during Sonolyses of Benzene and
Cyclohexane in Tetrachloroethylene............................................................ 73
5.3 Sonolytic Products of Pure Thioethers ................................ 75
5.4 Sonolytic Products of Pure Thiophene and Its Derivatives ................................. 77
5.5 Sonolytic Products of N-Heterocycles............................................ 80
6 Discussion...........................................................................................................84
6.1 Sonolytic Kinetics in Aqueous Solutions ............................................................
6.1.1 Comparison of Aquasonolytic Rate Constants of Model Compounds ........ 84
6.1.2 Roles of Thermostability of Organic Substrates .......................................... 84
6.1.3 Roles of Henry’s Law Constant and Transfer of Substrate.......................... 86
6.1.4 Roles of Vapor Pressure of Substrate........................................................... 87
6.1.5 Roles of Hydrophobicity of Substrate on Aquasonolytic Rate
Constants ...................................................................................................... 89
6.1.6 Effects of Initial Concentration of Organic Substrate on the Kinetics......... 92
6.2 Sonolyses of Organic Substrates.......................................................................... 94
6.2.1 Effects of Volatility of Liquids on the Sonolytic Rates ............................... 94
6.2.2 Sonolyses of Selected C H Hydrocarbons at Low Temperature................ 97 6 X
6.2.3 Sonolytic Pseudo-Yields of the Selected N-Heterocycles ........................... 98
6.2.4 Effects of Ultrasonic Intensity and Density on Sonolyses of Organic
Substrates ..................................................................................................... 99
IV
6.3 Roles of Lipophobicity and Volatility of Hydrocarbons on Sonolyses in
Nonaqueous Solutions....................................................................................... 102
6.3.1 Effects of LogP of Organic Solvents on Sonolyses of the Selected OW
C H Hydrocarbons.................... 102 6 x
6.3.2 Effects of Vapor pressures of C H Hydrocarbons on Sonolytic Rates 6 x
in Organic Solvents .............................