@article {2243, title = {Altering pyridinone N-substituents to optimise activity as potential prodrugs for Alzheimer{\textquoteright}s disease}, journal = {Dalton Transactions}, number = {45}, year = {2008}, note = {ISI Document Delivery No.: 371METimes Cited: 5Cited Reference Count: 29Scott, Lauren E. Page, Brent D. G. Patrick, Brian O. Orvig, Chris}, pages = {6364-6367}, type = {Article}, abstract = {Selective design modifications of specifically substituted 3-hydroxy-4(1H)-pyridinones show possibly advantageous ring freedom while maintaining metal-binding ability and antioxidant capacity, moving toward an efficient potential treatment for Alzheimer{\textquoteright}s disease.}, keywords = {aluminum, BLOOD-BRAIN-BARRIER, COMPLEXES, DISORDERS, DIVALENT, IRON CHELATORS, PENETRATION, STABILITIES, therapy, TRIVALENT METAL-IONS}, isbn = {1477-9226}, url = {://000260834600005}, author = {Scott, L. E. and Page, B. D. G. and Patrick, B. O. and Orvig, Chris} } @article {510, title = {Synthesis and solution studies of the complexes of trivalent lanthanides with the tetraazamacrocycle TETA-(PO)(2)}, journal = {Inorganic Chemistry}, volume = {41}, number = {4}, year = {2002}, note = {ISI Document Delivery No.: 524GATimes Cited: 9Cited Reference Count: 29}, month = {Feb}, pages = {685-692}, type = {Article}, abstract = {A new potentially multidentate hexaprotic ligand H-6[TETA-(PO)(2)] has been prepared by reaction of ethylenediamine-N,N{\textquoteright}-diacetic acid (EDDA), paraformaldehyde, and phosphinic acid; its coordination properties with three lanthanide ions (La3+, Gd3+, and Lu3+) have been explored. The structures of the complexes were studied in aqueous solution by potentiometric pH titrations and by P-31 NMR spectroscopy. Four acidity constants were determined potentiometrically in the range 2.5 < pH < 14. The four measured pK(a) values can be divided into two groups, and within each group the initial deprotonation was found to have little effect on the second. Variable temperature 31P and P-31{H-1} EXSY NMR spectra showed that, for [Lu(TETA-(PO)(2))](3-), the two phosphorus atoms exist in different chemical environments and undergo an exchange process which is very fast on the NMR time scale at room temperature. This result is consistent with one of the phosphinate residues coordinating the metal ion and exchanging with a free analogue. In the case of [La(TETA-(PO)(2))](3-), only one temperature invariant signal is observed in P-31 NMR spectra; it corresponds to both phosphinate residues remaining uncoordinated to La3+. The stability of [Ln-(TETA-(PO)(2))](3-) has an order of La3+ > Gd3+ > Lu3+. The coordination of one phosphinate residue to Lu3+ brings the metal ion closer to the plane of four nitrogens and farther from the four carboxylate arms, resulting in [Lu(TETA-(PO)(2))](3-) having a lower stability than the corresponding La3+ and Gd3+ complexes. A pM-pH distribution diagram showed that introducing two phosphinate groups into TETA renders [Gd(TETA-(PO)(2))](3-) more stable than [Gd(TETA)](-). The selectivity factor of the ligand for Gd3+ vs Ca2+, Zn2+, and Cu2+ has been calculated, and the hydration number for [Dy(TETA-(PO)(2))](3-) has been measured by O-17 NMR spectroscopy to be zero.}, keywords = {ACID, CRYSTAL-STRUCTURE, DERIVATIVES, DOTA, DYNAMICS, IONS, LIGANDS, luminescence, STABILITIES}, isbn = {0020-1669}, url = {://000174003700014}, author = {Song, B. and Storr, T. and Liu, S. and Orvig, Chris} } @article {5201, title = {Proton- and lanthanide-coordinating properties of the tetraaza macrocycle (EDDA-KA)(2) in aqueous solution}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {79}, number = {5-6}, year = {2001}, note = {ISI Document Delivery No.: 456EVTimes Cited: 4Cited Reference Count: 36}, month = {May}, pages = {1058-1067}, type = {Article}, abstract = {{The new potentially multidentate ligand (EDDA-KA)(2) has been prepared and its acid-base properties determined. Its coordination properties with three lanthanide ions (La3+, Gd3+, and Lu3+) and Fe3+ have been studied in aqueous solution (I = 0.16 M NaCl, 25degreesC) by potentiometric pH, spectrophotometric, and H-1 NMR titrations. In total, eight pK(a) values could be determined by these diverse methods. From the H-1 NMR titrations, all the deprotonation steps could be determined and assigned (in groups). Strong hydrogen bonding among two nitrogen atoms and one oxygen atom on the pyrone ring was observed, and the corresponding pK(a) values were estimated to be 13.2 and 14.0. By comparison with similar systems, an equilibrium constant for the formation of the hydrogen bond was estimated}, keywords = {ACID-BASE, acidity constants, ALKALINE-EARTH, amino, BINDING-PROPERTIES, carboxylate chelator, CHEMISTRY, CONTRAST AGENTS, DERIVATIVES, DYNAMICS, Fe3+, GADOLINIUM, Gd3+, La3+, Lu3+, METAL-COMPLEXES, STABILITIES, stability constants}, isbn = {0008-4042}, url = {://000170070900078}, author = {Song, B. and Kurokawa, G. S. and Liu, S. and Orvig, Chris} } @article {3927, title = {Tripodal aminophenolate ligand complexes of aluminum(III), gallium(III), and indium(III) in water}, journal = {Inorganic Chemistry}, volume = {36}, number = {2}, year = {1997}, note = {ISI Document Delivery No.: WC887Times Cited: 34Cited Reference Count: 53}, month = {Jan}, pages = {236-248}, type = {Article}, abstract = {Four water-soluble amine phenols have been prepared: tris(((2-hydroxy-5-sulfobenzyl)amino)ethyl)amine (H(6)TRNS), 1,1,1-tris(((2-hydroxy-5-sulfobenzyl)amino)methyl)ethane (H(6)TAMS), 1,2,3-tris((2-hydroxy-5-sulfobenzyl)amino)propane (H(6)TAPS), and cis,cis-1,3,5-tris((2-hydroxy-5-sulfobenzyl)amino)cyclohexane (H(6)TACS). Complex formation constants have been measured at 25 degrees C (mu = 0.16 M NaCl): log K [M(TRNS)](3-) ([M(HTRNS)](2-)) M = Ga 28.55 (36.90), In 29.3 (34.9); log K [M(TAMS)](3-) ([M(HTAMS)](2-)) M = Al 22.5 (29.3), Ga 31.53, In 28.49; log K [M(TAPS)](3-) ([M(HTAPS)](2-)) M = Al 22.8 (29.0), Ga 31.54 (35.15), In 27.56 (31.93). The order of stability is Ga(III) > In(III) > Al(III) for H(6)TAMS and H(6)TAPS, while far H(6)TRNS it is Ga(III) approximate to In(lII) > Al(III). The solution structures of the complexes have been probed by multinuclear NMR (H-1, C-13, Al-27, Ga-71, In-115) and UV spectroscopic studies, and these solution structures are compared with solid state structures for analogous complexes. The H-1 NMR spectrum in D2O establishes TAPS to be preorganized for metal ion binding. H(6)TACS exists in the wrong conformation for metal ion binding, and this results in slow complexation kinetics and relatively weaker binding.}, keywords = {ACID, BINDING, EQUILIBRIUM-CONSTANTS, GA(III), HUMAN-SERUM TRANSFERRIN, IN(III), IN-VIVO, METAL-IONS, SCHIFF-BASE LIGANDS, STABILITIES}, isbn = {0020-1669}, url = {://A1997WC88700021}, author = {Caravan, P. and Orvig, Chris} } @article {3855, title = {Selectivity of potentially hexadentate amine phenols for Ga3+ and In3+ in aqueous solution}, journal = {Inorganic Chemistry}, volume = {35}, number = {3}, year = {1996}, note = {ISI Document Delivery No.: TT717Times Cited: 29Cited Reference Count: 48}, month = {Jan}, pages = {715-724}, type = {Article}, abstract = {{A new series of linear N4O2 amine phenols (H(2)badd, H(2)Brbadd, and H(2)Clbadd) based on N,N{\textquoteright}-bis(3-aminopropyl)-ethylenediamine (tnentn) were prepared and characterized by spectroscopic techniques. Monocationic hexadentate metal complexes with the tnentn-based amine phenols were obtained from the reactions of Ga3+ and In3+ with the Linear amine phenol in the presence of a weak base (acetate). The molecular structure of [Ga(Brbadd)]ClO4 has been determined by X-ray crystallography; crystals of [Ga(Brbadd)][ClO4] (C22H30Br2ClGaN4O6) are orthorhombic: a = 12.462(1) Angstrom}, keywords = {ACID, aluminum, CHELATION, CRYSTAL, GA-68, gallium, IONS, LIGANDS, STABILITIES, TRIVALENT METAL-COMPLEXES}, isbn = {0020-1669}, url = {://A1996TT71700029}, author = {Wong, E. and Caravan, P. and Liu, S. and Rettig, S. J. and Orvig, Chris} } @article {2863, title = {HIGHLY FLEXIBLE CHELATING LIGANDS FOR GROUP 13 METALS - DESIGN AND SYNTHESIS OF HEXADENTATE (N3O3) TRIPODAL AMINE PHENOL LIGAND COMPLEXES OF ALUMINUM, GALLIUM, AND INDIUM}, journal = {Inorganic Chemistry}, volume = {32}, number = {9}, year = {1993}, note = {ISI Document Delivery No.: KZ801Times Cited: 48Cited Reference Count: 38}, month = {Apr}, pages = {1756-1765}, type = {Article}, abstract = {{New, potentially hexadentate (N3O3) amine phenol ligands (H3IIa = 1,1,1-tris(((2{\textquoteright}-hydroxybenzyl)amino)methyl)ethane; H3IIb = 1,1,1-tris(((5{\textquoteright}-chloro-2{\textquoteright}-hydroxybenzyl)amino)methyl)ethane; H3IIC = 1,1,1-tris(((5{\textquoteright}-bromo-2{\textquoteright}-hydroxybenzyl)amino)methyl)ethane; H3IId = 1,1,1-tris(((3{\textquoteright},5{\textquoteright}-dichloro-2{\textquoteright}-hydroxybenzyl)amino)methyl)ethane) have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). The N3O3 amine phenols are KBH4 reduction products of the corresponding Schiff bases derived from the condensation reactions of 1,1,1-tris(2-aminomethyl)ethane (tame) with 3 equiv of either salicylaldehyde or ring-substituted salicylaldehydes. Neutral binary metal complexes, [M(L)] (M = Al, Ga, In; L = IIa, IIb, IIc, IId) were obtained from the reactions of Al3+, Ga3+, or In3+ With N3O3 amine phenols in the presence of 3 equiv of a base (acetate or hydroxide). The molecular structures of [AI(IIc)]4[Na(H2O)]2)(ClO4)2.6.2H2O, [Ga(IIa)].4.4H2O, and [In(IIa)].4.6H2O were determined by X-ray methods. Crystals of [Al(IIc)]4[Na(H2O)]2(ClO4)2.6.2H2O are orthorhombic, Pbcn}, keywords = {FE(III), GA(III), HEXAKIS(THIOETHER) COORDINATION, IN(III), IONS, Iron(III), MOLECULAR-STRUCTURE, STABILITIES, TRIDENTATE}, isbn = {0020-1669}, url = {://A1993KZ80100036}, author = {Liu, S. and Wong, E. and Karunaratne, V. and Rettig, S. J. and Orvig, Chris} }