@article {1443, title = {Lanthanide(III) and group 13 metal ion complexes of tripodal amino phosphinate ligands}, journal = {Dalton Transactions}, number = {1}, year = {2006}, note = {ISI Document Delivery No.: 993PUTimes Cited: 2Cited Reference Count: 23}, pages = {31-38}, type = {Article}, abstract = {The tripodal amino-phosphinate ligands, tris(4-(phenylphosphinato)-3-benzyl-3-azabutyl) amine (H(3)ppba center dot 2HCl center dot H2O) and tris(4-(phenylphosphinato)-3-azabutyl) amine (H(3)ppa center dot HCl center dot H2O) were synthesized and reacted with Al3+, Ga3+, In3+ and the lanthanides (Ln(3+)). At 2 : 1 H(3)ppba to metal ratios, complexes of the type [M(H(3)ppba)(2)](3+) (M = Al3+, Ga3+, In3+, Ho3+-Lu3+) were isolated. The bicapped [Ga(H(3)ppba)(2)](NO3)(2)Cl center dot 3CH(3)OH was structurally characterized and was shown indirectly by various techniques to be isostructural with the other [M(H(3)ppba)(2)](3+) complexes. Also, at 2:1 H(3)ppba to metal ratios, complexes of the type [M(H(4)ppba)(2)](5+) (M = La3+-Tb3+) were characterized, and the X-ray structure of [Gd(H(4)ppba)(2)](NO3)(4)Cl center dot 3CH(3)OH was determined. At 1:1 H(3)ppba to metal ratios, complexes of the type [M(H(4)ppba)](4+) (M = La3+-Er3+) were isolated and characterized. Elemental analysis and spectroscopic evidence supported the formation of a 1:1 monocapped complex. Reaction of 1:1 ratios of H(3)ppa with Ln(3+) and In3+ yielded complexes of the type [M(H(3)ppa)](3+) (M = La3+-Yb3+) but with Ga3+, complex of the type [Ga(ppa)]center dot 3H(2)O was obtained. Reaction of 1:1 ratios of H(3)ppa with Ln(3+) and In3+ yielded complexes of the type [M(H(3)ppa)](3+) (M = La3+-Yb3+) but with Ga3+ a neutral complex [Ga(ppa)]center dot 3H(2)O was obtained. The formation of an encapsulated 1:1 complex is supported by elemental analysis and spectroscopic evidence.}, keywords = {ACID, BEARING, CIRCULARLY-POLARIZED LUMINESCENCE, CONTRAST AGENTS, MAGNETIC-RESONANCE, NMR, RELAXOMETRY}, isbn = {1477-9226}, url = {://000233968200004}, author = {Kovacs, M. S. and Monga, V. and Patrick, B. O. and Orvig, Chris} } @article {1443, title = {Lanthanide(III) and group 13 metal ion complexes of tripodal amino phosphinate ligands}, journal = {Dalton Transactions}, number = {1}, year = {2006}, note = {ISI Document Delivery No.: 993PUTimes Cited: 2Cited Reference Count: 23}, pages = {31-38}, type = {Article}, abstract = {The tripodal amino-phosphinate ligands, tris(4-(phenylphosphinato)-3-benzyl-3-azabutyl) amine (H(3)ppba center dot 2HCl center dot H2O) and tris(4-(phenylphosphinato)-3-azabutyl) amine (H(3)ppa center dot HCl center dot H2O) were synthesized and reacted with Al3+, Ga3+, In3+ and the lanthanides (Ln(3+)). At 2 : 1 H(3)ppba to metal ratios, complexes of the type [M(H(3)ppba)(2)](3+) (M = Al3+, Ga3+, In3+, Ho3+-Lu3+) were isolated. The bicapped [Ga(H(3)ppba)(2)](NO3)(2)Cl center dot 3CH(3)OH was structurally characterized and was shown indirectly by various techniques to be isostructural with the other [M(H(3)ppba)(2)](3+) complexes. Also, at 2:1 H(3)ppba to metal ratios, complexes of the type [M(H(4)ppba)(2)](5+) (M = La3+-Tb3+) were characterized, and the X-ray structure of [Gd(H(4)ppba)(2)](NO3)(4)Cl center dot 3CH(3)OH was determined. At 1:1 H(3)ppba to metal ratios, complexes of the type [M(H(4)ppba)](4+) (M = La3+-Er3+) were isolated and characterized. Elemental analysis and spectroscopic evidence supported the formation of a 1:1 monocapped complex. Reaction of 1:1 ratios of H(3)ppa with Ln(3+) and In3+ yielded complexes of the type [M(H(3)ppa)](3+) (M = La3+-Yb3+) but with Ga3+, complex of the type [Ga(ppa)]center dot 3H(2)O was obtained. Reaction of 1:1 ratios of H(3)ppa with Ln(3+) and In3+ yielded complexes of the type [M(H(3)ppa)](3+) (M = La3+-Yb3+) but with Ga3+ a neutral complex [Ga(ppa)]center dot 3H(2)O was obtained. The formation of an encapsulated 1:1 complex is supported by elemental analysis and spectroscopic evidence.}, keywords = {ACID, BEARING, CIRCULARLY-POLARIZED LUMINESCENCE, CONTRAST AGENTS, MAGNETIC-RESONANCE, NMR, RELAXOMETRY}, isbn = {1477-9226}, url = {://000233968200004}, author = {Kovacs, M. S. and Monga, V. and Patrick, B. O. 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} }