101
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Zhou Y, Yu H, Zhang L, Sun J, Wu L, Lu Q, Wang L. Host properties of cucurbit [7] uril: fluorescence enhancement of acridine orange. J INCL PHENOM MACRO 2008. [DOI: 10.1007/s10847-008-9414-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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102
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Shaikh M, Mohanty J, Singh PK, Nau WM, Pal H. Complexation of acridine orange by cucurbit[7]uril and β-cyclodextrin: photophysical effects and pKashifts. Photochem Photobiol Sci 2008; 7:408-14. [DOI: 10.1039/b715815g] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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103
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Shaikh M, Mohanty J, Bhasikuttan AC, Pal H. Tuning dual emission behavior of p-dialkylaminobenzonitriles by supramolecular interactions with cyclodextrin hosts. Photochem Photobiol Sci 2008; 7:979-85. [DOI: 10.1039/b719518d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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104
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Protolytic equilibrium in lyophilic nanosized dispersions: Differentiating influence of the pseudophase and salt effects. PURE APPL CHEM 2008. [DOI: 10.1351/pac200880071459] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The so-called apparent ionization constants of various acids (mainly indicator dyes) in versatile organized solutions are analyzed. Aqueous micellar solutions of colloidal surfactants and related lyophilic colloidal systems display a strong differentiating influence on the acidic strength of indicators located in the dispersed pseudophase, i.e., non-uniform changes of pKa on going from water to the given system. This concept allows the influence of such media on acid-base properties of dissolved reagents to be rationalized. It is demonstrated that the differentiating phenomenon is the main reason for limitation of the common electrostatic model of acid-base interactions, and is the principal hindrance to exact evaluations of the interfacial electrical potentials of ionic micelles by means of acid-base indicators. Salt effects, i.e., the influence of supporting electrolytes on the apparent ionization constants of acid-base indicators in the Stern region of ionic micelles, are considered. These salt effects can be conventionally divided into two kinds, namely, general (normal) and special (specific) effects. While the first type adds up to screening of the surface charge, the second one consists in micellar transitions caused by hydrophobic counterions.
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105
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Lodi A, Caselli M, Casnati A, Momicchioli F, Sansone F, Vanossi D, Ponterini G. Solvent-dependent host–guest complexation of two homologous merocyanines by a water-soluble calix[8]arene: Spectroscopic analysis and structural calculations. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2007.01.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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106
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Liu Y, Li CJ, Guo DS, Pan ZH, Li Z. A Comparative Study of Complexation of β-Cyclodextrin, Calix[4]arenesulfonate and Cucurbit[7]uril with Dye Guests: Fluorescence Behavior and Binding Ability. Supramol Chem 2007. [DOI: 10.1080/10610270601145444] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Yu Liu
- a State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry , Nankai University , Tianjin, 300071, P. R. China
| | - Chun-Ju Li
- a State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry , Nankai University , Tianjin, 300071, P. R. China
| | - Dong-Sheng Guo
- a State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry , Nankai University , Tianjin, 300071, P. R. China
| | - Zhong-Huai Pan
- a State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry , Nankai University , Tianjin, 300071, P. R. China
| | - Zhe Li
- a State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry , Nankai University , Tianjin, 300071, P. R. China
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107
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Nau WM, Hennig A, Koner AL. Squeezing Fluorescent Dyes into Nanoscale Containers—The Supramolecular Approach to Radiative Decay Engineering. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/4243_2007_007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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108
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Cui Y, Mo HJ, Chen JC, Niu YL, Zhong YR, Zheng KC, Ye BH. Anion-selective interaction and colorimeter by an optical metalloreceptor based on ruthenium(II) 2,2'-biimidazole: hydrogen bonding and proton transfer. Inorg Chem 2007; 46:6427-36. [PMID: 17602611 DOI: 10.1021/ic7004562] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new anion sensor [Ru(bpy)2(H2biim)](PF6)2 (1) (bpy = 2,2'-bipyridine and H2biim = 2,2'-biimidazole) has been developed, in which the Ru(II)-bpy moiety acts as a chromophore and the H2biim ligand as an anion receptor via hydrogen bonding. A systematic investigation shows that 1 is an eligible sensor for various anions. It donates protons for hydrogen bonding to Cl-, Br-, I-, NO3-, HSO4-, H2PO4-, and OAc- anions and further actualizes monoproton transfer to the OAc- anion, changing color from yellow to orange brown. The fluoride ion has a high affinity toward the N-H group of the H2biim ligand for proton transfer, rather than hydrogen bonding, because of the formation of the highly stable HF2- anion, resulting in stepwise deprotonation of the two N-H fragments. These processes are signaled by vivid color changes from yellow to orange brown and then to violet because of second-sphere donor-acceptor interactions between Ru(II)-H2biim and the anions. The significant color changes can be distinguished visually. The processes are not only determined by the basicity of anion but also by the strength of hydrogen bonding and the stability of the anion-receptor complexes. The design strategy and remarkable photophysical properties of sensor 1 help to extend the development of anion sensors.
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Affiliation(s)
- Ying Cui
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, China
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109
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The outer-sphere association of p-sulfonatothiacalix[4]arene with some Co(III) complexes: the effect on their redox activity in aqueous solutions. J INCL PHENOM MACRO 2007. [DOI: 10.1007/s10847-007-9290-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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110
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Mohanty J, Pal H, Ray AK, Kumar S, Nau WM. Supramolecular Dye Laser with Cucurbit[7]uril in Water. Chemphyschem 2007; 8:54-6. [PMID: 17171726 DOI: 10.1002/cphc.200600625] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jyotirmayee Mohanty
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
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111
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The Nature of Aqueous Solutions of a Cationic Calix[4]arene: A Comparative Study of Dye–Calixarene and Dye–Surfactant Interactions. SENSORS 2006. [DOI: 10.3390/s6080962] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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112
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Megyesi M, Biczók L. Considerable fluorescence enhancement upon supramolecular complex formation between berberine and p-sulfonated calixarenes. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.04.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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113
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Rhile IJ, Markle TF, Nagao H, DiPasquale AG, Lam OP, Lockwood MA, Rotter K, Mayer JM. Concerted proton-electron transfer in the oxidation of hydrogen-bonded phenols. J Am Chem Soc 2006; 128:6075-88. [PMID: 16669677 PMCID: PMC2518092 DOI: 10.1021/ja054167+] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three phenols with pendant, hydrogen-bonded bases (HOAr-B) have been oxidized in MeCN with various one-electron oxidants. The bases are a primary amine (-CPh(2)NH(2)), an imidazole, and a pyridine. The product of chemical and quasi-reversible electrochemical oxidations in each case is the phenoxyl radical in which the phenolic proton has transferred to the base, (*)OAr-BH(+), a proton-coupled electron transfer (PCET) process. The redox potentials for these oxidations are lower than for other phenols, predominately from the driving force for proton movement. One-electron oxidation of the phenols occurs by a concerted proton-electron transfer (CPET) mechanism, based on thermochemical arguments, isotope effects, and DeltaDeltaG(++)/DeltaDeltaG degrees . The data rule out stepwise paths involving initial electron transfer to form the phenol radical cations [(*)(+)HOAr-B] or initial proton transfer to give the zwitterions [(-)OAr-BH(+)]. The rate constant for heterogeneous electron transfer from HOAr-NH(2) to a platinum electrode has been derived from electrochemical measurements. For oxidations of HOAr-NH(2), the dependence of the solution rate constants on driving force, on temperature, and on the nature of the oxidant, and the correspondence between the homogeneous and heterogeneous rate constants, are all consistent with the application of adiabatic Marcus theory. The CPET reorganization energies, lambda = 23-56 kcal mol(-)(1), are large in comparison with those for electron transfer reactions of aromatic compounds. The reactions are not highly non-adiabatic, based on minimum values of H(rp) derived from the temperature dependence of the rate constants. These are among the first detailed analyses of CPET reactions where the proton and electron move to different sites.
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Affiliation(s)
- Ian J. Rhile
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Todd F. Markle
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Hirotaka Nagao
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Antonio G. DiPasquale
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Oahn P. Lam
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Mark A. Lockwood
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - Katrina Rotter
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
| | - James M. Mayer
- Department of Chemistry, Campus Box 351700, University of Washington, Seattle, WA 98195-1700
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114
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Liu Y, Yang EC, Chen Y, Guo DS, Ding F. Molecular Selective Binding of Pyridinium Guest Ions by Water-Soluble Calix[4]arenes. European J Org Chem 2005. [DOI: 10.1002/ejoc.200500354] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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115
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Yang W, de Villiers MM. Effect of 4-sulphonato-calix[n]arenes and cyclodextrins on the solubilization of niclosamide, a poorly water soluble anthelmintic. AAPS JOURNAL 2005; 7:E241-8. [PMID: 16146345 PMCID: PMC2751513 DOI: 10.1208/aapsj070123] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study investigated the effect of water-soluble 4-sulphonato-calix[n]arenes, cyclodextrins, and combinations of these macromolecules on the aqueous solubility of a poorly water-soluble drug, niclosamide. Complexation between the macromolecules and niclosamide was confirmed by thermal analysis and phase solubility studies in a pH 7.0 Mcllvaine buffer kept at 30 degrees C. Results show that the increase in solubility ranked as follows: 4-sulphonato-calix[6]arene + hydroxypropyl-beta-cyclodextrin (HP-beta-CD) > 4-sulphonato-calix[6]arene + beta-cyclodextrin > 4-sulphonato-calix[6]arene + gamma-cyclodextrin = HP-beta-CD > 4-sulphonato-calix[6]arene > 4-sulphonato-calix[8]arene = 4-sulphonato-calix[4]arene > beta-cyclodextrin . Type B phase solubility profiles were observed, indicating a decrease in solubility at concentrations > 0.004 to 0.005 mol/L of the 4-sulphonato-calix[n]arenes or combinations of 4-sulphonato-calix[6]arene and the cyclodextrins. However, below this concentration, the greatest increase in the aqueous solubility niclosamide was observed when 4-sulphonato-calix[6]arene and HP-beta-CD were combined. This increase in solubility was additive.
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Affiliation(s)
- Wenzhan Yang
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 71209 Monroe, LA
| | - Melgardt M. de Villiers
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 71209 Monroe, LA
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116
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Kubinyi M, Vidóczy T, Varga O, Nagy K, Bitter I. Absorption and fluorescence spectroscopic study on complexation of Oxazine 1 Dye by calix[8]arenesulfonate. APPLIED SPECTROSCOPY 2005; 59:134-139. [PMID: 15720749 DOI: 10.1366/0003702052940477] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
It has been established by combined absorption and fluorescence measurements that the cationic dye Oxazine 1 (OX) and the polyvalent anionic host calix[8]arenesulfonate (SCA8) form two complexes in simultaneous reactions: OX + SCA8 <--> OX.SCA8 (1), and OX.SCA8 + OX <--> OX(2).SCA8 (2). The equilibrium constants for the two reactions, as functions of the ionic strength (I), and the absorption and fluorescence spectra of the two complex species have been determined by a least-squares fitting method from the experimental data. The variations of the binding constants with the ionic strength could be described on the basis of Debye-Huckel theory. The equilibrium constants are large; their values extrapolated to I = 0 are K(1) = 5.5 x 10(6) M(-1) and K(2) = 4.4 x 10(5) M(-1). The fluorescence of OX undergoes a strong static quenching upon complexation. These results indicate that the complexes are held together by strong electrostatic forces. The addition of non-fluorescent tetramethylammonium chloride to OX-SCA8 mixtures results in a dramatic fluorescent enhancement, which demonstrates the potential applicability of this supramolecular system in fluorescence assays.
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Affiliation(s)
- Miklós Kubinyi
- Department of Physical Chemistry, Budapest University of Technology and Economics, 1521 Budapest, Hungary.
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117
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Liu Y, Li XQ, Chen Y, Guan XD. Spectrophotometric Study of Selective Binding Behaviors of Dye Molecules by Pyridine- and Bipyridine-Modified β-Cyclodextrin Derivatives with a Functional Tether in Aqueous Solution. J Phys Chem B 2004. [DOI: 10.1021/jp046363t] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu Liu
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Xue-Qing Li
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Yong Chen
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Xu-Dong Guan
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
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118
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Liu Y, Yang YW, Cao R, Song SH, Zhang HY, Wang LH. Thermodynamic Origin of Molecular Selective Binding of Bile Salts by Aminated β-Cyclodextrins. J Phys Chem B 2003. [DOI: 10.1021/jp036366q] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu Liu
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Ying-Wei Yang
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Rui Cao
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Shi-Hui Song
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Heng-Yi Zhang
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Li-Hua Wang
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
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119
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Fluorescence and room temperature phosphorescence of 6-bromo-2-naphthol in β-cyclodextrin solution and its selective molecular recognition for cyclohexane. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(03)00877-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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120
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Woods M, Sherry AD. Synthesis and luminescence studies of aryl substituted tetraamide complexes of europium(III): a new approach to pH responsive luminescent europium probes. Inorg Chem 2003; 42:4401-8. [PMID: 12844313 DOI: 10.1021/ic0300823] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DOTA-tetraamide ligands having extended phenol or pyridine substituents have been synthesized. The (5)D(0) --> (7)F(J) deltaJ = 1 and 2 emission bands in the corresponding europium(III) complexes differ in their sensitivity to solution pH. This offers the potential for developing pH responsive probes for in vivo imaging that are independent of probe concentration.
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Affiliation(s)
- Mark Woods
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75083, and Rogers Magnetic Resonance Center, Department of Radiology, University of Texas Southwestern Medical Center, 5801 Forest Park Road, Dallas, Texas 75235, USA
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121
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Lucarini M, Mugnaini V, Pedulli GF, Guerra M. Hydrogen-bonding effects on the properties of phenoxyl radicals. An EPR, kinetic, and computational study. J Am Chem Soc 2003; 125:8318-29. [PMID: 12837104 DOI: 10.1021/ja034963k] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of 1,1,1,3,3,3-hexafluoropropan-2-ol (HFP) on the properties of phenoxyl radicals has been investigated. HFP produces large variations of the phenoxyl hyperfine splitting constants indicative of a large redistribution of electron spin density, which can be accounted for by the increased importance of the mesomeric structures with electric charge separation. The conformational rigidity of phenoxyl radicals with electron-releasing substituents is also greatly enhanced in the presence of HFP, as demonstrated by the 2 kcal/mol increase in the activation energy for the internal rotation of the p-OMe group in the p-methoxyphenoxyl radical. By using the EPR equilibration technique, we have found that in phenols the O-H bond dissociation enthalpy (BDE) is lowered in the presence of HFP because it preferentially stabilizes the phenoxyl radical. In phenols containing groups such as OR that are acceptors of H-bonds, the interaction between HFP and the substituent is stronger in the phenol than in the corresponding phenoxyl radical because the radical oxygen behaves as an electron-withdrawing group, which decreases the complexating ability of the substituent. In phenols containing OH or NH(2) groups, EPR experiments performed in H-bond accepting solvents showed that the interaction between the solvent and the substituent is much stronger in the phenoxyl radical than in the parent phenol because of the electron-withdrawing effect of the radical oxygen, which makes more acidic, and therefore more available to give H-bonds, the OH or NH(2) groups. These experimental results have been confirmed by DFT calculations. The effect of HFP solvent on the reactivity of phenols toward alkyl radicals has also been investigated. The results indicated that the decrease of BDE observed in the presence of HFP is not accompanied by a larger reactivity. The origin of this unexpected behavior has been shown by DFT computations. Finally, a remarkable increase in the persistency of the alpha-tocopheroxyl radical has been observed in the presence of HFP.
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Affiliation(s)
- Marco Lucarini
- Dipartimento di Chimica Organica A. Mangini, Università di Bologna, Via S. Donato 15, I-40127 Bologna, Italy.
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