@article {4984,
	title = {Coaggregation of paramagnetic d- and f-block metal ions with a podand-framework amine phenol ligand},
	journal = {Inorganic Chemistry},
	volume = {39},
	number = {3},
	year = {2000},
	note = {ISI Document Delivery No.: 283FQTimes Cited: 37Cited Reference Count: 86},
	month = {Feb},
	pages = {508-516},
	type = {Article},
	abstract = {This report covers initial studies in the coaggregation of nickel (Ni2+) and lanthanide (Ln(3+)) metal ions to form complexes with interesting structural and magnetic properties. The tripodal amine phenol ligand H(3)tam (1,1,1-tris(((2-hydroxybenzyl)amino)methyl)ethane) is shown to be particularly accommodating with respect to the geometric constraints of both transition and lanthanide metal ions, forming isolable complexes with both of these ion types. In the solid-state structure of [Ni(H(2)tam)(CH3CN)]PF6.2.5CH(3)CN.0.5CH(3)OH (1), the Ni(II) center has a distorted octahedral geometry, with an N3O2 donor set from the [H(2)tam](-) ligand and a coordinated solvent (acetonitrile) occupying the sixth site. The reaction of stoichiometric amounts of H(3)tam with the Ni(II) ion in the presence of lanthanide(III) ions provides [LnNi(2)(tam)(2)](+) cationic complexes which contain coaggregated metal ions. These complexes are isolable and have been characterized by a variety of analytical techniques, with mass spectrometry proving to be particularly diagnostic. The solid-state structures of [LaNi2(tam)(2)(CH3OH)(1/2)-(CH3CH2OH)(1/2)(H2O)]ClO4.0.5CH(3)OH.4H(2)O (2), [DyNi2(tam)(2)(CH3OH)(H2O)]ClO4.CH3OH.H2O (6), and [YbNi2(tam)(2)(H2O)]ClO4.2.58H(2)O (9) have been determined. Each complex contains two octahedral Ni(II) ions, each of which is encapsulated by the ligand tam(3-) in an N3O3 coordination sphere; each [Ni(tam)](-)unit caps the lanthanide(III) ion via bridging phenoxy oxygen donor atoms. In 2, La3+ is eight-coordinated, while in 6, Dy(III) is seven- (to "weakly eight-") coordinated, and Yb(III) in 9 has a six-coordination environment. The complexes are symmetrically different, 2 possessing C-1 symmetry and 6 and 9 having CI symmetry. Magnetic studies of 2, 6, and 9 indicate that antiferromagnetic exchange coupling between the Ni(II) and Ln(III) ions increases with decreasing ionic radius of Ln(III).},
	keywords = {AQUEOUS-SOLUTION, COMPARTMENTAL SCHIFF-BASES, COPPER-LANTHANOID COMPLEXES, CRYSTAL-STRUCTURES, DINICKEL(II) COMPLEXES, HEPTADENTATE LIGANDS, MACROCYCLIC COMPLEXES, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURE, SPIN-EXCHANGE},
	isbn = {0020-1669},
	url = {<Go to ISI>://000085266100018},
	author = {Xu, Z. Q. and Read, P. W. and Hibbs, D. E. and Hursthouse, M. B. and Malik, K. M. A. and Patrick, B. O. and Rettig, S. J. and Seid, M. and Summers, D. A. and Pink, M. and Thompson, R. C. and Orvig, Chris}
}
@article {4984,
	title = {Coaggregation of paramagnetic d- and f-block metal ions with a podand-framework amine phenol ligand},
	journal = {Inorganic Chemistry},
	volume = {39},
	number = {3},
	year = {2000},
	note = {ISI Document Delivery No.: 283FQTimes Cited: 37Cited Reference Count: 86},
	month = {Feb},
	pages = {508-516},
	type = {Article},
	abstract = {This report covers initial studies in the coaggregation of nickel (Ni2+) and lanthanide (Ln(3+)) metal ions to form complexes with interesting structural and magnetic properties. The tripodal amine phenol ligand H(3)tam (1,1,1-tris(((2-hydroxybenzyl)amino)methyl)ethane) is shown to be particularly accommodating with respect to the geometric constraints of both transition and lanthanide metal ions, forming isolable complexes with both of these ion types. In the solid-state structure of [Ni(H(2)tam)(CH3CN)]PF6.2.5CH(3)CN.0.5CH(3)OH (1), the Ni(II) center has a distorted octahedral geometry, with an N3O2 donor set from the [H(2)tam](-) ligand and a coordinated solvent (acetonitrile) occupying the sixth site. The reaction of stoichiometric amounts of H(3)tam with the Ni(II) ion in the presence of lanthanide(III) ions provides [LnNi(2)(tam)(2)](+) cationic complexes which contain coaggregated metal ions. These complexes are isolable and have been characterized by a variety of analytical techniques, with mass spectrometry proving to be particularly diagnostic. The solid-state structures of [LaNi2(tam)(2)(CH3OH)(1/2)-(CH3CH2OH)(1/2)(H2O)]ClO4.0.5CH(3)OH.4H(2)O (2), [DyNi2(tam)(2)(CH3OH)(H2O)]ClO4.CH3OH.H2O (6), and [YbNi2(tam)(2)(H2O)]ClO4.2.58H(2)O (9) have been determined. Each complex contains two octahedral Ni(II) ions, each of which is encapsulated by the ligand tam(3-) in an N3O3 coordination sphere; each [Ni(tam)](-)unit caps the lanthanide(III) ion via bridging phenoxy oxygen donor atoms. In 2, La3+ is eight-coordinated, while in 6, Dy(III) is seven- (to "weakly eight-") coordinated, and Yb(III) in 9 has a six-coordination environment. The complexes are symmetrically different, 2 possessing C-1 symmetry and 6 and 9 having CI symmetry. Magnetic studies of 2, 6, and 9 indicate that antiferromagnetic exchange coupling between the Ni(II) and Ln(III) ions increases with decreasing ionic radius of Ln(III).},
	keywords = {AQUEOUS-SOLUTION, COMPARTMENTAL SCHIFF-BASES, COPPER-LANTHANOID COMPLEXES, CRYSTAL-STRUCTURES, DINICKEL(II) COMPLEXES, HEPTADENTATE LIGANDS, MACROCYCLIC COMPLEXES, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURE, SPIN-EXCHANGE},
	isbn = {0020-1669},
	url = {<Go to ISI>://000085266100018},
	author = {Xu, Z. Q. and Read, P. W. and Hibbs, D. E. and Hursthouse, M. B. and Malik, K. M. A. and Patrick, B. O. and Rettig, S. J. and Seid, M. and Summers, D. A. and Pink, M. and Thompson, R. C. and Orvig, Chris}
}
@article {4336,
	title = {Tightening the hydrophobic belt: Effects of backbone and donor group variation on podand ligand complexes of the lanthanides},
	journal = {Inorganic Chemistry},
	volume = {37},
	number = {7},
	year = {1998},
	note = {ISI Document Delivery No.: ZG944Times Cited: 44Cited Reference Count: 53},
	month = {Apr},
	pages = {1637-1647},
	type = {Article},
	abstract = {{The N4O3 tripodal aminomethylene phosphinato ligand tris(4-phenylphosphinato-3-methyl-3-azabutyl)amine (H-3-ppma) forms mono- and bis(ligand) complexes with lanthanide(III) metal ions Ln when Ln = Sm-Lu. The formation constants of the Lu (log beta(1) = 1.79, log beta(2) = 4.40) and the Yb (log beta(1) = 2.25, log beta(2) = 4.42) complexes were determined at pH = 1.5 using an unusual P-31 NMR spectroscopic method. The molecular structure of the lutetium complex [Lu(H(3)ppma)(2)](NO3)(3) . 3H(2)O (C60H96LuN11O24P6) was solved by X-ray methods; it crystallizes in the trigonal space group R(3) over barc$, with a = 19.060(1) Angstrom},
	keywords = {AMINE PHENOL LIGANDS, BIOLOGICAL-SYSTEMS, CHEMISTRY, COORDINATION, DESIGN, HEPTADENTATE LIGANDS, METAL-IONS, NMR SHIFTS, NUCLEAR MAGNETIC-RESONANCE, STABILITY},
	isbn = {0020-1669},
	url = {<Go to ISI>://000073055700034},
	author = {Lowe, M. P. and Caravan, P. and Rettig, S. J. and Orvig, Chris}
}
@article {3925,
	title = {Selectivity among, and aggregation of, lanthanide ions},
	journal = {Journal of Alloys and Compounds},
	volume = {249},
	number = {1-2},
	year = {1997},
	note = {ISI Document Delivery No.: XC092Times Cited: 4Cited Reference Count: 1421st Rare Earth Research ConferenceJUL 07-12, 1996DULUTH, MNRare Earth Res Conf Inc, Univ Minnesota, USR Optonix Inc, Amer Chem Soc, Petr Res Fund, Arris Int Corp, Baotou Steel \& Rare Earth Co, US},
	month = {Mar},
	pages = {49-51},
	type = {Proceedings Paper},
	abstract = {Ligands that show selectivity towards, and aggregation of, lanthanides are of intrinsic interest in coordination chemistry. We have shown that Schiff base and amine phenolate ligands exhibit a variety of coordination modes in lanthanide(III) complexes, and that tren-(tris((2-amino)ethyl)amine)-based amine phenolates show selectivity towards later lanthanide(III) ions. By altering the nature of the amine phenolate ligand backbone the coordination mode of the ligand in solution can be easily controlled. Selectivity among lanthanide(III) ions can be controlled by substitution of the parent ligand donor atoms (phenolate oxygen) with donor atoms of a different type (e.g. phosphinate oxygen). By derivatizing the ligand to include more donor atoms and by stiffening the backbone, it is possible to control the aggregation of lanthanide(III) ions (enabling the formation of dimeric lanthanide complexes).},
	keywords = {aggregation of lanthanide ions, AMINE PHENOL LIGANDS, COMPLEXES, DESIGN, HEPTADENTATE LIGANDS, METAL-IONS, selectivity among lanthanide ions},
	isbn = {0925-8388},
	url = {<Go to ISI>://A1997XC09200010},
	author = {Caravan, P. and Lowe, M. P. and Read, P. W. and Rettig, S. J. and Yang, L. W. and Orvig, Chris}
}
@article {3266,
	title = {POTENTIOMETRIC, CALORIMETRIC, AND SOLUTION NMR-STUDIES OF A TRIDENTATE LIGAND WHICH HAS A MARKED PREFERENCE FOR FORMATION OF BIS(LIGAND) VERSUS MONO(LIGAND) LANTHANIDE COMPLEXES AND WHICH EXHIBITS HIGH SELECTIVITY FOR HEAVIER LANTHANIDES},
	journal = {Journal of the American Chemical Society},
	volume = {117},
	number = {45},
	year = {1995},
	note = {ISI Document Delivery No.: TE739Times Cited: 69Cited Reference Count: 59},
	month = {Nov},
	pages = {11230-11238},
	type = {Article},
	abstract = {A new water-soluble N4O3 tripodal amine phenol ligand, tris(((2-hydroxy-5-sulfobenzyl)amino)ethyl)amine (H(3)TRNS) has been synthesized, and its complexation properties with six lanthanide(III) ions (Ln, Nd, Gd, Ho, Yb, Lu) have been probed. In water, the ligand coordinates in a tridentate fashion through the three phenolate oxygen atoms to give mono- and bis(ligand) complexes. The bis complexes are proposed to be 7-coordinate containing one bound water as evinced by O-17 NMR experiments on the Dy3+ complex. while the mono complexes are proposed to have a coordination number of eight or nine. The stepwise formation constants for the 1:1 and 2:1 (L:M) complexes have been measured at 25 degrees C (mu = 0.16 M NaCl) for Nd3+ (log K-1 = 6.41, log K-2 6.34), Gd3+ (log K-1 = 6.67, log K-2 = 7.69), Ho3+ (log K-1 = 7.67, log K-2 = 8.75), and Yb3+ (log K-1 = 8.53, log K-2 = 9.73). The formation constants show an increasing affinity and an unprecedented selectivity for the heavier lanthanides (beta(2(yb)) - beta(2(Nd)) = 10(5.5)). Furthermore, the stepwise stability constant for the 2:1 complex is increasingly greater than that for the 1:1 complexes of Gd3+, Ho3+, and Yb3+, while K-1 and K-2 for the 1:1 and 2:1 complexes of Nd3+ are approximately the same. Solution calorimetry shows that the selectivity for the heavier lanthanides is an enthalpic effect (Delta H-beta 2 = -45.11 (Yb) and -13.71 kJ . mol(-1) (Nd)), while the anomalous behavior in formation constants (K-2 > K-1) is predominantly entropic (Delta S-2 > Delta S-1) and is rationalized in terms of salvation of the complexes, Lanthanum(III) forms only the 1:1 complex (log K = 5.65) which precipitates from solution.},
	keywords = {AGENTS, AMINE PHENOL LIGANDS, AQUEOUS, BIOLOGICAL-SYSTEMS, CHEMISTRY, EXCHANGE, HEPTADENTATE LIGANDS, METAL-IONS, NUCLEAR MAGNETIC-RESONANCE, probes, SHIFT-REAGENTS, WATER},
	isbn = {0002-7863},
	url = {<Go to ISI>://A1995TE73900021},
	author = {Caravan, P. and Hedlund, T. and Liu, S. and Sjoberg, S. and Orvig, Chris}
}
@article {2865,
	title = {BULKY ORTHO 3-METHOXY GROUPS ON N4O3 AMINE PHENOL LIGANDS PRODUCING 6-COORDINATE BIS(LIGAND)LANTHANIDE COMPLEX CATIONS [LN(H3L)2]3+ (LN = PR, GD H3L = TRIS(((2-HYDROXY-3-METHOXYBENZYL)AMINO)ETHYL)AMINE)},
	journal = {Inorganic Chemistry},
	volume = {32},
	number = {12},
	year = {1993},
	note = {ISI Document Delivery No.: LG549Times Cited: 39Cited Reference Count: 11},
	month = {Jun},
	pages = {2773-2778},
	type = {Article},
	abstract = {{The synthesis and characterization of an N4O3 amine phenol (tris(((2-hydroxy-3-methoxybenzyl)amino)ethyl)amine, H3L4) and its lanthanide complexes [Ln(H3LA)(NO3)3] (Ln = Pr, Nd) and [Ln(H3L4)2](NO3)3 (Ln = Pr, Nd, Gd, Yb) are reported. The N4O3 amine phenol ligand is the KBH4 reduction product of the Schiff base derived from the reaction of tris(2-aminoethyl)amine (tren) and 3 equiv of o-vanillin. The reactions of lanthanide nitrates with 1 equiv of H3L4 produce nine-coordinate type II complexes, [Ln(H3L4)(NO3)3] (Ln = Pr, Nd), in which H3L4 acts as a tridentate O3 ligand and six-coordinate bis(ligand) type IV complexes, [Ln(H3L4)2](NO3)3 (Ln = Gd, Yb). The latter were prepared from the reactions of lanthanide nitrates with 2 equiv of H3L4 in the presence of sodium hydroxide. The X-ray crystal structures of [Ln(H3L4)2](NO3)3.xH2O.YMeOH (Ln = Pr},
	keywords = {HEPTADENTATE LIGANDS},
	isbn = {0020-1669},
	url = {<Go to ISI>://A1993LG54900032},
	author = {Liu, S. and Yang, L. W. and Rettig, S. J. and Orvig, Chris}
}
