Research & Teaching Faculty

Default Header Image

Coaggregation of paramagnetic d- and f-block metal ions with a podand-framework amine phenol ligand

TitleCoaggregation of paramagnetic d- and f-block metal ions with a podand-framework amine phenol ligand
Publication TypeJournal Article
Year of Publication2000
AuthorsXu, ZQ, Read, PW, Hibbs, DE, Hursthouse, MB, Malik, KMA, Patrick, BO, Rettig, SJ, Seid, M, Summers, DA, Pink, M, Thompson, RC, Orvig, C
JournalInorganic Chemistry
Volume39
Pagination508-516
Date PublishedFeb
Type of ArticleArticle
ISBN Number0020-1669
KeywordsAQUEOUS-SOLUTION, COMPARTMENTAL SCHIFF-BASES, COPPER-LANTHANOID COMPLEXES, CRYSTAL-STRUCTURES, DINICKEL(II) COMPLEXES, HEPTADENTATE LIGANDS, MACROCYCLIC COMPLEXES, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURE, SPIN-EXCHANGE
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).

URL<Go to ISI>://000085266100018