Chemistry of technetium. Elaboration of the mechanism of action of skeletal imaging agents and development of technetium Schiff base complexes

Thesis/Dissertation · Fri Jan 01 00:00:00 EST 1982

OSTI ID:5037827

Jurisson, S S

Tc-99m skeletal imaging agents contain diphosphonate ligands coordinated to a technetium center. To investigate the chemistry of coordinated diphosphonates, complexes of the type ((en)/sub 2/Co(O/sub 2/P(OH)C(R)(R')P(OH)O/sub 2/)/sup n+/ have been synthesized and characterized. The affinities of these species for calcium ion in solution have been determined and found to be dependent on the substituents, R and R', of the diphosphonate moiety. The single crystal X-ray structural determination of ((en)/sub 2/Co(O/sub 2/P(OH)CH/sub 2/P(OH)O/sub 2/)ClO/sub 4/ x 2H/sub 2/O illustrates the configuration of a coordinated diphosphonate in the solid state and allows for the implication of possible binding modes of this species to the calcium ion in solution. A series of Tc(V) complexes containing tetradentate Schiff base ligands (derived from diamines and either acetylacetonates or salicylaldehyde) has been synthesized and characterized. An investigation of the reactivity of the Tc(V)-Schiff base complexes with phosphines led to the development of a series of Tc(III)-Schiff base complexes containing two coordinated phosphine ligands, i.e., tr-(Tc(Schiff base)(PRR')/sub 2/)PF/sub 6/. These complexes show intriguing redox behavior in that they exhibit both reversible Tc(III)/Tc(II) and Tc(III)/Tc(IV) couples. The substituents on the Schiff base and phosphine ligands have significant effects on the redox potentials of the technetium(III) center and on the MTLCT bands observed for these complexes. Those substituents which make the Schiff base and phosphine ligands better sigma donors make the Tc(III) more difficult to reduce to Tc(II) and easier to oxidize to Tc(IV). The relatonship between the energy of the MTLCT band and the E/sup 0/ values for these complexes is linear with slopes to unity, suggesting that the ligands contribute equally to these properties.

• OSTI ID: 5037827
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
SCHIFF BASES
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TECHNETIUM COMPLEXES
CHEMISTRY
PHOSPHINES
REACTIVITY
TECHNETIUM 99
X-RAY DIFFRACTION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COHERENT SCATTERING
COMPLEXES
DIFFRACTION
HOURS LIVING RADIOISOTOPES
IMINES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
RADIOISOTOPES
SCATTERING
TECHNETIUM ISOTOPES
TRANSITION ELEMENT COMPLEXES
YEARS LIVING RADIOISOTOPES
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials