Jozef Hodyl PhD Thesis - Theses - Flinders University

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Figure 3.9The structure of histidine showing the H A and H B protons the former of which wasmonitored in the 1 H NMR titration experiments.The chemical shifts for the H A proton resonances of the two enantiomers, whenbound to the host were marginally different, with that of the L- enantiomer slightlyfurther downfield than that of the D- enantiomer, Figure 3.10.NN(b)(L)(D)O OH HH OH HNNOHHO O ONH 2 COO -MeCd 2+- OOC H H 2 N HNNNN(L) (D)49(a)Figure 3.101 H NMR spectra of (a) DL-sodium histidinate, 83, and (b) 10:1 ratio of 49:sodium DLhistidinate.These chemical shift assignments were made using the chemical shift data obtainedfrom the 1 H NMR monitored titration experiments of each enantiomer separately.62
This phenomenon correlates well with the chemical shifts obtained with receptor26. 186 A difference from the studies of the complexation of both these histidinateswith receptor 26, is that with the latter the logK values for both complexes are ofequal magnitude, logK (4.2 ± 0.2), whereas the logK values obtained for thecomplexes with receptor 49, differ marginally, D-histidinate, logK (3.54 ± 0.09) andL-histidinate, logK (3.37 ± 0.04) . This indicates slight thermodynamic selectivitytoward the D-enantiomer with receptor 49. It is noteworthy that the H A resonance forL-histidinate is broader than the one for D-histidinate showing that the less tightlybound guest is also more labile.3.2.71 H NMR titrations with hydroxy substituted benzoatesTo ascertain whether hydroxy substitution on the aromatic rings of the guest specieswould affect the inclusion capabilities of [Cd(TracHP12)](ClO 4 ) 2 , 49, a small groupof hydroxy substituted benzoate guests was also studied. It is known thattheformation of hydrogen bonds between the hydroxy hydrogen atoms of the hostpendant-arms and the carboxylic oxygen atoms of the guest is the primary mode ofbinding experienced in these host-guest complexes. Therefore, this study wasconducted to determine whether non-classical hydrogen bonding interactionsbetween the guest hydroxy groups and the pendant arm aromatic moieties might be afactor in determining the magnitude of the binding strength of the guest molecule.This would be of interest since, a trend that showed binding constants with o-hydroxybenzoate > m-hydroxybenzoate > p-hydroxybenzoate was observed inrelated work by the Wainwright group using receptor 29 (page 98) in 20% aqueousdioxane.A generic structure representing the sodium salt of a hydroxy substitutedbenzoate guest species is shown in Figure 3.11.63
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Silica Immobilised MetalIon Activat
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ABSTRACTImmobilisation of functiona
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DECLARATIONI certify that this thes
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EtOHGPDMSGPDMESGPSGPTSethanolglycid
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CHAPTER ONEINTRODUCTION
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The focus of this work was to prepa
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sequestering anions has proved to b
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ange of pH due to its high basicity
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nitrophenol or p-nitrophenolate wit
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It has been shown by NMR and crysta
Page 23 and 24: within the cavity of a p-tert-butyl
Page 25 and 26: 60 in 0.5% DMSO-MeCN (v/v). 82 The
Page 27 and 28: synthesised bi- tri- and tetra - π
Page 29 and 30: adopt a trans-III conformation, whe
Page 31 and 32: amide oxygen atoms on the pendant a
Page 33 and 34: apparent there is, nonetheless, evi
Page 35 and 36: However, hetero-N-substitution on t
Page 37 and 38: Si-OH +- OH SiO - + H 2 OFor surfac
Page 39 and 40: 35This material was obtained with a
Page 41 and 42: OOSiOHOROR OSiOHOOOSiOSiOSiOSiOSiOS
Page 43 and 44: Tetraaza metal complexes immobilise
Page 45 and 46: CHAPTER TWOSYNTHESIS OF MACROCYCLIC
Page 47 and 48: In addition, successful immobilisat
Page 49 and 50: 3233Figure 2.3Reaction of 3-(glycid
Page 51 and 52: The methodology chosen was adapted
Page 53 and 54: agreed with literature values. 109R
Page 55 and 56: XS HO O H61, n = 262, n = 3n+ClOSO6
Page 57 and 58: anhydrous ethanol, Scheme 2.7. The
Page 59 and 60: 75Figure 2.5 Structure of (S)-(-)-p
Page 61 and 62: metal ion coordination the pendant
Page 63 and 64: CHAPTER THREEGUEST MOLECULE INCLUSI
Page 65 and 66: 3.1 where K A is the association, o
Page 67 and 68: 0.5cχG∆δ∆δGbaχ GFigure 3.1S
Page 69 and 70: χG∆δ∆δGFigure 3.4 Job's Plot
Page 71 and 72: The downfield movement of the guest
Page 73: arm framework. The relative magnitu
Page 77 and 78: non-classical hydrogen bonding is g
Page 79 and 80: The full set of logK values obtaine
Page 81 and 82: such that they would indicate precl
Page 83 and 84: CHAPTER 4MODIFICATION OF THE SILICA
Page 85 and 86: Chemical modification of the silica
Page 87 and 88: GPTSGPDMESFigure 4.4Schematic depic
Page 89 and 90: GPS, 33, linker material with an ex
Page 91 and 92: free νOHτSiOHνSi-O-SiδH 2 Oasym
Page 93 and 94: 224, 225the surface silanol groups.
Page 95 and 96: esonances, the spectrum for Si-GPS-
Page 97 and 98: increase in surface coverage from t
Page 99 and 100: and, more so due to the larger size
Page 101 and 102: CHAPTER 5METAL ION UPTAKE STUDIES W
Page 103 and 104: Scheme 5.1 Metal(II) ion coordinati
Page 105 and 106: linker material, Si-GPS, 33; endcap
Page 107 and 108: [Cd(Trac)](ClO 4 ) 2 , 94, or Si-GP
Page 109 and 110: CHAPTER 6GUEST MOLECULE INCLUSION S
Page 111 and 112: and D-histidinate. Guest inclusion
Page 113 and 114: Table 6.2Percent inclusion data for
Page 115 and 116: contains two hydroxy groups in the
Page 117 and 118: methoxy group, as portrayed by the
Page 119 and 120: these guest molecules with receptor
Page 121 and 122: only about half of that taken up by
Page 123 and 124: Percent inclusion values for these
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Table 6.7Percent guest inclusion of
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6.1.7 Guest inclusion studies with
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A1 3542Neutral GuestBAnionic GuestH
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A1 46 7532 Anionic Guest8BCHostHost
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extent, meta-positioned hydroxy gro
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δ obs (ppm)6.2146.2136.2126.2116.2
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CHAPTER 7EXPERIMENTAL7.1 General Ex
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inding constants (logK values) and
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delay time of 4 s. 13 C CPMAS NMR s
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C, -CH 2 - CH 2 OSO 2 ); 68.11 (1 C
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A solution of 69 (2.00 g, 10.1 mmol
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Bn, meta); 127.79 (1 C, Bn, para);
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added in a single portion. The mixt
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dioxane): δ 158.67 (1 C, C=O); 135
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1-(benzyloxycarbonyl)-4,7,10-tris-(
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1,4,7-tris-((S)-2-hydroxy-3-phenoxy
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1,4,7-tris(S)-2-hydroxy-3-[4-((2-(2
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1,4,7-tris(S)-2-hydroxy-3-[4-(2-(2-
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1-(2-hydroxypropyl)-4,7,10-tris-((S
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7.11 Preparation of the silica mate
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To a suspension of 33 (1.48 g, 1.1
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gel-like suspension that was cooled
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Si-GPS-Tri-Trac, 4545The title comp
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APPENDIX ABINDING CONSTANT DETERMIN
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1.01000.880δ obs (ppm)0.60.4logK =
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APPENDIX BDETERMINATION OF STOICHIO
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0.5χG∆δGFigure B.2χ GSimulated
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13 C CPMAS NMR SPECTRA OF SOME HIGH
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Si-GPS-[Cd(Trac)(2,5-diydroxybenzoa
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REFERENCES
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15. D. Tzalis and Y. Tor, Tetrahedr
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42. A. P. Davis and R. S.Wareham, A
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69. R. J. Bergeron, M. A. Channing
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93. C. B. Smith, A. K. W. Stephens,
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118. D. D. Dischino, E. J. Delaney,
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144. X. Huang, X. Chang, Q. He, Y.
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169. J. M. Klunder, T. Onami and K.
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197. K. A. Connors, Binding Constan
Page 201 and 202:
221. J. Blumel, J. Am. Chem. Soc.,
Page 203:
247. W. Likussar and D. F. Botz, An
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Jozef Hodyl PhD Thesis - Theses - Flinders University

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