Jozef Hodyl PhD Thesis - Theses - Flinders University

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contact with an aqueous environment and therefore water soluble guest species. Thiswould, in essence, endow the receptor part of the material with a greater degree ofwettability enabling the inclusion process to occur in a single phase. Accordingly,guest inclusion studies were performed with two silica immobilised receptormaterials Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, and Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 , 96,appended with hydroxy terminated polyether (HTPE) moieties at the periphery ofeach receptor's cavity. Both materials were expected to possess a level of wettabilitythrough increased hydrogen bonding between their ethereal and hydroxy oxygensand water molecules. Solubility of the silica free materials was evaluated bysuspending 50 mg of each of the precursor macrocyclic compounds DiPTrac, 47, andTriPTrac, 48, in 1 cm -3 of water and gradually adding a small amount of water toeach over time until it was completely dissolved. Solubility in water at 298 Kobtained for these compounds was 0.007 mol L -1 for 47 and, 0.032 mol L -1 for 48.These values are significant in the context of Trac, 46, which has essentially zerosolubility in water. Furthermore, when water is added to either of materials 95 or 96the resultant suspension is visibly different than that for 94. A perceivabletranslucence with the appearance of the material blending with the aqueousenvironment gives the impression that these materials are more wettable. The resultsfrom the study of the uptake of hydroxybenzoate guests with Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, and Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 , 96, are given inTable 6.5. The percent inclusion values for p-hydroxybenzoate and m-hydroxybenzoate for all three materials do not vary greatly. For o-hydroxybenzoateand 2,6-dihydroxybenzoate the immobilised HTPE materials show very differentpercent inclusion values. Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, exhibits similar bindingto Si-GPS-[Cd(Trac)](ClO 4 ) 2 , 94, but Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 , 96, includes105
only about half of that taken up by the two former materials.Table 6.5Guest inclusion data for hydroxybenzoate guest species with receptor complexes Si-GPS-[Cd(Trac)](ClO 4 ) 2 , 94, Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, and Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 , 96, conducted in aqueous media at pH 7 in 0.01 mol dm -3HEPES buffer at 298 K.Percent Guest InclusionSilica Immobilised ReceptorsGuest Species Trac, 94 DiPTrac, 95 TriPTrac, 96apK abenzoate 30 b b 4.19p-hydroxybenzoate 32 50 31 4.54m-hydroxybenzoate 48 45 30 4.30o-hydroxybenzoate 81 76 45 2.972,6-dihydroxybenzoate 95 92 46 1.05a Values obtained in H 2 O from PHYSPROP database for their respective conjugate acids. 202b Not attempted.Lowering of the percent inclusion values seen for Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 ,96, could be related to the HTPE chain length of this material. Whereas Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, has two ethoxy moieties between its aromatic andhydroxy groups, Si-GPS-[Cd(TriPTrac)](ClO 4 ) 2 , 96, has three. The extra length inthe HTPE chain could result in orientation of the chain into the host cavity resultingin hydrogen bonding with the hydroxy groups at its base or even with each other.This would effectively create a barrier at the opening to the cavity as well as anobstruction of the host hydroxy groups making them sterically unavailable to guestmolecules. This is shown in Figure 6.5. On the other hand the polyether chain of Si-GPS-[Cd(DiPTrac)](ClO 4 ) 2 , 95, may be too short to interact with the binding cavityand hence the percent inclusion values for this material mirror values for receptor 94.106
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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
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within the cavity of a p-tert-butyl
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60 in 0.5% DMSO-MeCN (v/v). 82 The
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synthesised bi- tri- and tetra - π
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adopt a trans-III conformation, whe
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amide oxygen atoms on the pendant a
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apparent there is, nonetheless, evi
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However, hetero-N-substitution on t
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Si-OH +- OH SiO - + H 2 OFor surfac
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35This material was obtained with a
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OOSiOHOROR OSiOHOOOSiOSiOSiOSiOSiOS
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Tetraaza metal complexes immobilise
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CHAPTER TWOSYNTHESIS OF MACROCYCLIC
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In addition, successful immobilisat
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3233Figure 2.3Reaction of 3-(glycid
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The methodology chosen was adapted
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agreed with literature values. 109R
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XS HO O H61, n = 262, n = 3n+ClOSO6
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anhydrous ethanol, Scheme 2.7. The
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75Figure 2.5 Structure of (S)-(-)-p
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metal ion coordination the pendant
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CHAPTER THREEGUEST MOLECULE INCLUSI
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3.1 where K A is the association, o
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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 and 74: arm framework. The relative magnitu
Page 75 and 76: This phenomenon correlates well wit
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: these guest molecules with receptor
Page 123 and 124: Percent inclusion values for these
Page 125 and 126: Table 6.7Percent guest inclusion of
Page 127 and 128: 6.1.7 Guest inclusion studies with
Page 129 and 130: A1 3542Neutral GuestBAnionic GuestH
Page 131 and 132: A1 46 7532 Anionic Guest8BCHostHost
Page 133 and 134: extent, meta-positioned hydroxy gro
Page 135 and 136: δ obs (ppm)6.2146.2136.2126.2116.2
Page 137 and 138: CHAPTER 7EXPERIMENTAL7.1 General Ex
Page 139 and 140: inding constants (logK values) and
Page 141 and 142: delay time of 4 s. 13 C CPMAS NMR s
Page 143 and 144: C, -CH 2 - CH 2 OSO 2 ); 68.11 (1 C
Page 145 and 146: A solution of 69 (2.00 g, 10.1 mmol
Page 147 and 148: Bn, meta); 127.79 (1 C, Bn, para);
Page 149 and 150: added in a single portion. The mixt
Page 151 and 152: dioxane): δ 158.67 (1 C, C=O); 135
Page 153 and 154: 1-(benzyloxycarbonyl)-4,7,10-tris-(
Page 155 and 156: 1,4,7-tris-((S)-2-hydroxy-3-phenoxy
Page 157 and 158: 1,4,7-tris(S)-2-hydroxy-3-[4-((2-(2
Page 159 and 160: 1,4,7-tris(S)-2-hydroxy-3-[4-(2-(2-
Page 161 and 162: 1-(2-hydroxypropyl)-4,7,10-tris-((S
Page 163 and 164: 7.11 Preparation of the silica mate
Page 165 and 166: To a suspension of 33 (1.48 g, 1.1
Page 167 and 168: gel-like suspension that was cooled
Page 169 and 170: 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
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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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