the production of thymoquinone from thymol and carvacrol

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such as diethylenetriamine (dien) and triethylenetetramine (trien). Adding four - CH2CO2 - groups to an ethylenediamine framework gives a hexadentate ligand, which can single-handedly satisfy the secondary valence of a transition-metal ion (Figgis 1966). Figure 3.4. Typical polydentate ligands (Source: Keim et al. 2002) In the catalyst synthesis, the encapsulation of metal complexes into the zeolites method is known as a ship in a bottle procedure. Encapsulation of metal complexes is occurred in the super cages of the zeolite. Ship in a bottle approach involving the entrapments of a bulky complex in a zeolite cage, has been widely used to immobilize metal complexes of phthalocyanines, porphyrin and Shiff’s base type ligands as seen in Figure 3.5 (Arends et al. 2001). Ligands bond with transition metal using the electron pairs. With this bonding ligand give electrons to the transition metal. Electropositive metal ion enters a second interaction with ligand to give accepted electrons from ligand to ligand. With this interaction metal gives electron and the bond between the metal and oxygen weakens. The weak bond between them causes the increasing susceptibility of reaction entrance of reactant. That is why transition metal complexes are used as catalysts. Transition 17
metal complexes catalyze the reaction and are considered to be good catalysts (Brunel et al. 1998). (a) (b) (c) Figure 3.5. (a) Shiff’s Base ligand (b) Phthalocyanine (c) Porphyrin In Figure 3.5 case (a), where W = -(CH2)2- ( H2salen) =-(CH-CH2)- ( H2Salpn) CH3 (Source:Ramesh et al.2003, Ramesh et al. 1996) =-(C2H4) NH (C2H4) - (H2 saldien) 18
Page 1 and 2: THE PRODUCTION OF THYMOQUINONE FROM
Page 3 and 4: ACKNOWLEDGEMENTS I would like to ac
Page 5 and 6: ÖZET Bu tezde, genel esnek ligand
Page 7 and 8: 5.4. Catalytic Monoterpene Oxidatio
Page 9 and 10: LIST OF FIGURES Figure Page Figure
Page 11 and 12: LIST OF TABLES Table Page Table 2.1
Page 13 and 14: of thymoquinone are limited only to
Page 15 and 16: advantages compared to homogeneous
Page 17 and 18: NH4 +2 generates the acid sides. Ca
Page 19 and 20: homogeneous internal structures whi
Page 21 and 22: CHAPTER 3 TRANSITION METALS AND COO
Page 23 and 24: not determined by orbital energy al
Page 25 and 26: 3.3.1. Oxidation State The transiti
Page 27: it surrounds the metal, forms very
Page 31 and 32: Figure 4.1. Flexible ligand method:
Page 33 and 34: included in the synthesis mixture.
Page 35 and 36: CHAPTER 5 OXIDATION OF MONOTERPENES
Page 37 and 38: In the GC-MS analysis of the oil of
Page 39 and 40: There are few studies on monoterpen
Page 41 and 42: Homolytic Pathways: Heterolytic Pat
Page 43 and 44: 6.1. Materials CHAPTER 6 EXPERIMENT
Page 45 and 46: inductively coupled plasma spectrom
Page 47 and 48: These tests were performed in detai
Page 49 and 50: Table 7.1. Metal content of encapsu
Page 51 and 52: 7.1.3. X-ray Diffraction (XRD) Anal
Page 53 and 54: Figure 7.2 (cont.) 42
Page 55 and 56: ands observed in the region 1200-16
Page 57 and 58: Figure 7.5. IR spectra ligand (H2 s
Page 59 and 60: Figure 7.6. DSC analysis result sho
Page 61 and 62: 7.2. Catalytic Activities 7.2.1. De
Page 63 and 64: eaction products, among which TQ wa
Page 65 and 66: carvacrol conversion (%) 16 14 12 1
Page 67 and 68: e 11.6% with a small amount of THQ.
Page 69 and 70: during the oxidation process and th
Page 71 and 72: leaching of Cr (salpn) complexes fr
Page 73 and 74: 7.3.2. Effect of Temperature Four d
Page 75 and 76: 7.4. Oxidation of Thymol Carvacrol
Page 77 and 78: at 60 o C. Essentail oil contained
Page 79 and 80:
REFERENCES Anthony, F., 1999. Advan
Page 81 and 82:
Martin, R.R.L., Neves, G. 2001. “
Page 83 and 84:
APPENDIX A DETERMINATION OF HYDROGE
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