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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2009-9-2
pubmed:abstractText
The N(4)-macrocyclic ligand 2,10-dioxo-1,4,8,11-tetraazabicyclo[11.4.0]1,12-heptadeca-1(12),14,16-triene H(2)L has been synthesized by the [1 + 1] condensation reaction between N,N'-bis(chloroacetyl)-1,2-phenylenediamine and 1,3-propylenediamine. The coordination chemistry of this ligand has been investigated with the metal ions Cu(II), Ni(II), Zn(II), and Ga(III) (complexes 1, 2, 3 and 4, respectively). H(2)L and its metal complexes have been fully characterized by the use of NMR, UV/vis, electron paramagnetic resonance, and elemental analysis where appropriate. The four metal complexes 1-4 have been structurally characterized by X-ray crystallography which confirmed that in all cases the amide nitrogen atoms are deprotonated and coordinated to the metal center. Complexes 3 and 4 are five-coordinate with a water molecule and chloride ion occupying the apical site, respectively. Cyclic voltammetric measurements on complex 1 show that this complex is oxidized reversibly with a half-wave potential, E(1/2) = 0.47 V, and reduced irreversibly at E(P) = -1.84 V. Density functional theory calculations reproduce the geometries of the four complexes. The one-electron reduction and oxidation potentials for 1 were calculated by using two solvent models, DMF and H(2)O. The calculations indicated that the one electron oxidation of 1 may involve removal of an electron from the ligand as opposed to the metal center, producing a diradical. The diamide macrocyle is of interest for the development of new positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging agents, and a radiolabeled complex has been synthesized with the positron emitting isotope (64)Cu. In vivo biodistribution studies for the (64)Cu labeled complex, (64)Cu-1, in male Lewis rats, showed that the activity is cleared rapidly from the blood within 1-2 h post-administration.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1520-510X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
3
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7117-26
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Macrocyclic diamide ligand systems: potential chelators for 64Cu- and 68Ga-based positron emission tomography imaging agents.
pubmed:affiliation
Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK. p.barnard@latrobe.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural