A5036202487- Supramolecular Chemistry and Complexes
- Crystallography and molecular interactions
- Molecular Sensors and Ion Detection
- Metal complexes synthesis and properties
- Inorganic and Organometallic Chemistry
- Electrochemical Analysis and Applications
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Synthesis and Characterization of Heterocyclic Compounds
- Photochemistry and Electron Transfer Studies
- Chemical Reaction Mechanisms
- Oxidative Organic Chemistry Reactions
- Mass Spectrometry Techniques and Applications
- Lanthanide and Transition Metal Complexes
- DNA and Nucleic Acid Chemistry
- Organometallic Complex Synthesis and Catalysis
- Surfactants and Colloidal Systems
- Drug Solubulity and Delivery Systems
- Chemical Synthesis and Analysis
- Asymmetric Hydrogenation and Catalysis
- Molecular Junctions and Nanostructures
- Luminescence and Fluorescent Materials
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Fluorine in Organic Chemistry
- Magnetism in coordination complexes
Queen's University
2011-2023
University of Victoria
1983-1990
Brookhaven National Laboratory
1983
National Research Council Canada
1983
Extended X-ray absorption fine structure (EXAFS) techniques have been used to determine the differences in metal–ligand bond distances Δd0 for following couples (couple, Δd0/Å) Fe(H2O)2 +/3 +6, 0.13; Fe(CN)4 –/3 –6, 0.01; Fe(phen)2 +3, 0.00; Co(NH3)2 0.22; Co(bpy)3+/2 +, – 0.02; Co(phen)2 0.19; Ru(H2O)2 0.08; Ru(NH3)2 0.04. The Cr(H2O)2 +3 ion has four short and two long Cr—O bonds (2.07 2.30 Å, respectively) average +6 couple is 0.20 Å. rate constant +6/Fe(H2O)3 exchange reaction 1.1 dm3...
The synthesis of a new diboron compound, 5,5'-bis(BMes2)-2,2'-bipy (B2bipy, 1), has been accomplished. conjugation the 2,2'-bipy unit with two BMes2 groups in 1 found to greatly enhance electron-accepting ability boron centers, compared biphenyl analogue. is an effective chelate ligand for metal ions and three complexes; namely, [CuI(B2bipy)(PPh3)2][BF4], 2, PtII(B2bipy)Ph2, 3a, PtII(B2bipy)Me2, 3b, have synthesized. binding B2bipy was further significantly increase ability/Lewis acidity...
Abstract The effects of the encapsulation drugs and other molecules biomedical interest by cucurbit[ n ]uril ( =5–8, 10) host on chemical properties in aqueous solution are reviewed. cucurbituril complexation drug has been shown to generally increase guests’ p K a values through preferential inclusion protonated species, modulate equilibria involving guest, improve solubility solution, reduce toxicity side effects, as well enhance stability targeted delivery molecule. These benefits have led...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelf-assembling metal rotaxane complexes of .alpha.-cyclodextrinR. Stephen Wylie and Donal H. MacartneyCite this: J. Am. Chem. Soc. 1992, 114, 8, 3136–3138Publication Date (Print):April 1, 1992Publication History Published online1 May 2002Published inissue 1 April 1992https://pubs.acs.org/doi/10.1021/ja00034a069https://doi.org/10.1021/ja00034a069research-articleACS PublicationsRequest reuse permissionsArticle Views703Altmetric-Citations148LEARN...
The inclusion of protonated 2-aminoanthracene in the cavity cucurbit[7]uril increases its pKa values ground and excited states, resulting disappearance green emission neutral state significant enhancement blue emissions from guest.
The cucurbit[7]uril (CB[7]) host molecule forms very stable host-guest complexes with the local anaesthetics procaine (K(CB[7]) = (3.5 +/- 0.7) x 10(4) dm(3) mol(-1)), tetracaine (1.5 0.4) procainamide (7.8 1.6) dibucaine (1.8 10(5) mol(-1)) and prilocaine (2.6 0.6) in aqueous solution (pD 4.75). stability constants are 2-3 orders of magnitude greater than values reported for binding by comparably sized beta-cyclodextrin molecule. inclusion CB[7] raises first pK(a) 0.5-1.9 pK units, as...
Cucurbit[7]uril selectively binds the epigenetic mark Nε,Nε,Nε-trimethyllysine (LysMe3, KCB[7] = (1.8 ± 0.6)× 106 dm3 mol−1) by 3500-fold over lysine ((5.3 0.7) × 102 in aqueous solution, using ion–dipole interactions and hydrophobic effect, rather than cation–π interactions, as "aromatic cages" of p-SO3-calix[4]arene hosts or chromodomain proteins which recognize LysMe3. The trend LysMe3 > LysMe2 LysMe Lys follows recognition pattern HP1 other LysMen protein readers. With CB[6], protonation...
The macrocyclic Cucurbit[7]uril was evaluated for its<italic>in vivo</italic>toxicity profile, including developmental toxicity and organ-specific toxicities using zebrafish models.
We demonstrate for the first time that cucurbit[7]uril effectively reversed general anesthesia induced by tricaine in zebrafish models.
The macrocyclic host cucurbit[7]uril forms very stable complexes with the diprotonated (K(CB[7])(1) = 1.8 x 10(8) dm(3) mol(-1)), monoprotonated (K(CB[7])(2) 1.0 10(7) and neutral (K(CB[7])(3) 1.2 10(3) mol(-1)) of histamine H(2)-receptor antagonist ranitidine in aqueous solution. complexation behaviour was investigated using (1)H NMR UV-visible spectroscopy as a function pH pK(a) values guest were observed to increase (DeltapK(a1) 1.5 DeltapK(a2) 1.6) upon host-guest complex formation....
Cucurbit[7]uril significantly enhanced <italic>in vitro</italic> and vivo</italic> uptake of coumarin-6, on an epithelial cell model a zebrafish model.
The 2:1 guest-host complex of 2-aminopyridine hydrochloride with cucurbit[7]uril (CB[7]) undergoes a stereoselective [4+4] photodimerization reaction in aqueous solution to yield exclusively the anti-trans isomer 4,8-diamino-3,7-diazatricyclo[4.2.2.2(2,5)]dodeca-3,7,9,11-tetraene, and absence CB[7], photochemical produces syn-trans photodimers 4:1 ratio. In addition, encapsulation photodimer product CB[7] cavity stabilizes it respect otherwise observed rearomatization monomer at room temperature.
The blue fluorescence of acridizinium bromide (ADZ+) and the green 9-aminoacridizinium (AADZ+) in aqueous solutions can be almost entirely switched off upon double inclusion these guests cavity cucurbit[8]uril (CB[8]) owing to formation a nonfluorescent, noncovalent dimer complex, then effectively restored by adding cucurbit[7]uril (CB[7]) complex because it competitively extracts fluorophores out CB[8] cavity.
Inclusion of the alpha,alpha'-bis(3-(1-methylimidazolium))-p-xylene dication in cucurbit[7]uril (CB[7], K(CB[7]) = (4.3 x 10(9) M(-1)), with C-H...O=C hydrogen bonding between guest C(2)-protons and carbonyl oxygens host portals, inhibits H/D exchange for C(2)-proton k(OD) (25 degrees C, D2O) decreasing from 1.2 10(3) M(-1) s(-1) (pKa 22.3) absence CB[7] to 0.9 25.4) presence 1.1 equiv. CB[7].
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of the oxidation metal complexes by manganese(III) aquo ions in acidic perchlorate media: The Mn(H2O)62+-Mn(H2O)63+ electron-exchange rate constantDonal H. Macartney and Norman SutinCite this: Inorg. Chem. 1985, 24, 21, 3403–3409Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October 1985https://doi.org/10.1021/ic00215a022Request reuse permissionsArticle...
Cucurbit[7]uril binds, with considerable size selectivity, NR(4)(+), PR(4)(+), and SR(3)(+) cations (R=Me, Et, (n)Pr, (n)Bu), the smaller guests inside its cavity, rather than at carbonyl-lined portals.
The neutral host cucurbit[7]uril forms very stable complexes with a series of cationic cholines (R(3)NCH(2)CH(2)OR'(+)) and their phosphonium analogues (R(3)PCH(2)CH(2)OR'(+)) (R(3) = Me(3), Et(3), or Me(2)Bz, R(3)N quinuclidinium, R' H, COCH(3), CO(CH(2))(2)CH(3), PO(3)H), (+/-)-carnitine, in aqueous solution. complexation behaviour has been investigated using (1)H (31)P NMR spectroscopies, ESI mass spectrometry. complexation-induced chemical shift changes the guests clearly indicate...
Cucurbit[7]uril (CB[7]) forms very stable complexes with the α-axial 5,6-dimethylbenzimidazole (α-DMB) nucleotide base when dissociated from Co(III) center in vitamin B12 (CNCbl, KCB[7] = (7.5 ± 0.5) × 104 dm3 mol−1) and coenzyme (AdoCbl, (3.02 0.35) 106 mol−1). The inclusion of α-DMB ligand facilitates its release metal subsequent protonation, significantly higher pKbase-off values 3.77 6.61, than determined for free CNCbl (0.11) AdoCbl (2.67), respectively. Addition CB[7] to base-on form...
Vitamin B1 (1) and its phosphate derivatives, thiamine monophosphate (2) pyrophosphate (3), are shown to form stable 1:1 host–guest complexes with cucurbit[7]uril (CB[7]) in aqueous solution. The binding sites of CB[7] on these guests shift from the ethylthiazolium region 1 pyrimidine moiety 2 3 due presence groups, leading variations affinities as well C(2)–H/D exchange rate constants C(2)–H pKa values guest molecules.
Binding behaviors of two cucurbit[n]urils (CB[n]) hosts with the [CH3bpy(CH2)6bpyCH3]4+ (bpy = 4,4'-bipyridinium) guest were investigated by 1H NMR and MALDI-TOF-MS experiments. While CB[6] CB[7] form [2]pseudorotaxanes host located over hexamethylene chain guest, only forms a [3]pseudorotaxane both molecules residing bipyridinium groups. The initial vacates inclusion as result electrostatic steric repulsions that would arise in simultaneous binding adjacent aliphatic aromatic portions guest.
The host-guest stability constants for the inclusion of a series small neutral polar organic guests in cucurbit[7]uril (CB[7]) have been determined aqueous solution by (1)H NMR titrations. dependence constant on nature indicates that hydrophobic and dipole-quadrupole interactions are responsible binding. complexation-induced chemical shift changes guest proton resonances, coupled with energy-minimization calculations, suggest located such their dipole moment is aligned perpendicular...
Pseudorotaxanes may be assembled in aqueous solution using dicationic acetylcholinesterase inhibitors, such as succinylcholine, BW284c51, and α,ω-bis(trialkylammonium)alkane dications (or their phosphonium analogues), bolaform axles cucurbit[7]uril (CB[7]) the wheel. With exceptions of shorter [(CH3)3N(CH2)nN(CH3)3]2+ (n = 6, 8) dications, addition a second CB[7] results translocation first CB[7], that hydrophobic −NR3+ −PR3+ end groups (R Me or Et) are located cavities wheels, while central...
The kinetics and mechanism of the self-assemblies alpha- beta-cyclodextrin (CD) [2]rotaxanes, [(NC)5Fe-[pyRpy.CD]Fe(CN)5]6-, containing pentacyanoferrate(II)-stoppered 4,4'-bis(pyridyl) threads pyRpy (R = -CH CH-, -N=N-, -CH=N-N=CH-, -C(CH3)=N-N=C(CH3)-) have been investigated in aqueous solution by using visible 1H NMR spectroscopy. rotaxanes may be formed rapidly addition [Fe(CN)5OH2]3- ion to CD-included thread or slowly an excess CD dimeric [(NC)5Fe(pyRpy)Fe(CN)5]6- complex. In latter...