the production of thymoquinone from thymol and carvacrol

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Figure 7.4 (cont.) The IR spectra of the encapsulated complexes were essentially similar to that of the free complexes; this was observed from Figure 7.4. However, some IR bands of encapsulated complexes and free ligand showed some differences from each other. For example free ligand (H2salpn) exhibited (C=N) stretch at 1580 1/cm. In complexes, this band shifted to lower frequency. As seen in Table 7.2, this band appeared in the range 1523-1570 1/cm. This shift was the indication of the coordination of azomethine nitrogen to the metal. Our results showed good agreement with the results reported in the literature earlier (Maurya et al. 2002a; Maurya et al. 2003). According to the FTIR results, there was no significant expansion of the zeolite cavities, dealumination or structural changes during the encapsulation process. IR spectra of NaY zeolite, metal- exchanged zeolites and catalysts were shown in Figure 7.3. This indicated that, the structure of metal complexes fitted nicely within the cavity of the zeolite. The presence of several bands of low intensity in 2700–2900 1/cm regions indicated the existence of ethylene group of the amine residue of the ligand. 45
Figure 7.5. IR spectra ligand (H2 salpn) Table 7.2. IR spectral data of ligand, its neat and encapsulated complexes Compound IR (1/cm) νC=N νC=C H2 (salpn) 1580 1634 Cr(salpn)-NaY 1525 1626 Cr(salpn) 1531 1616 Fe(salpn)-NaY 1545 1635 Fe(salpn) 1570 1624 Bi(salpn)-NaY 1523 1638 Bi(salpn) 1570 1635 Ni(salpn)-NaY 1523 1639 Ni(salpn) 1546 1632 Zn(salpn)-NaY 1525 1640 Zn(salpn) 1554 1627 46
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 and 28: it surrounds the metal, forms very
Page 29 and 30: metal complexes catalyze the reacti
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: ands observed in the region 1200-16
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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