Low-symmetry, mixed-valent,. mu. -oxo technetium complexes with pyridine and halide ligands

Journal Article · Wed Mar 16 04:00:00 EST 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00214a026· OSTI ID:7147962

Clarke, M J; Kastner, M E; Podbielski, L A; Fackler, P H; Schreifels, J; Meinken, G; Srivastava, S C

Dinuclear, asymmetric, and dissymmetric ..mu..-oxo complexes of technetium in which the two Tc atoms are in intimate electronic communication, have been synthesized and structurally characterized. The two types of complexes are isomers differing in their arrangement of equatorial ligands around each technetium, with the configurations being X/sub 4/ and (pyridine)/sub 4/ for the dissymmetric case and X/sub 3/(pyr) and (pyr)/sub 3/X for the asymmetric. A compound representative of the asymmetric complexes, ((Pic)Cl/sub 3/(Pic)Tc-O-TcCl(Pic)/sub 3/Cl) (III), crystallizes in the monoclinic space group P2/sub 1/n with the following unit cell parameters: a = 12.421 A, b = 15,471 A, c = 18.764 A, ..beta.. = 93.174/sup 0/, and Z = 4. The geometry is essentially octahedral around each Tc, with the equatorial ligands on the opposite metal atoms being staggered relative to one another. Dissymmetric complexes of the type (X(L)/sub 4/Tc-O-TcX/sub 4/L), where X = Cl or Br and L = pyridine, 4-picoline, and 3,5 lutidine, are also formed by spontaneous self-assembly but are immediately derived from the asymmetric species. In the solid state, both types of compounds exhibit a small magnetic moment (..mu../sub eff/ approx. 0.9-1.3 ..beta..). EPR spectra of the dissymmetric complex, (Cl(Pic)/sub 4/Tc-O-TcCl/sub 4/(Pic)) (I), whose structure has been previously reported, are consistent with an axial, binuclear species, containing splitting by two I = /sup 9//sub 2/ metal nuclei. Infrared Tc-O stretching frequencies are in the range 698-726 cm/sup -1/, while Tc-Cl bands appear in the range 305-317 cm/sup -1/ and Tc-Br at at 235-266 cm/sup -1/. Tissue distributions of these complexes in animals are reported and discussed.

• Research Organization: Boston College, Chestnut Hill, MA (USA)
• OSTI ID: 7147962
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:6; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400400 -- Electrochemistry
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ABSORPTION SPECTROSCOPY
AZINES
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
CHEMICAL REACTION KINETICS
CHEMISTRY
COMPLEXES
CRYSTAL STRUCTURE
DATA
ELECTROCHEMISTRY
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
INFORMATION
KINETICS
LATTICE PARAMETERS
LIGANDS
MAGNETIC PROPERTIES
MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PYRIDINE
PYRIDINES
REACTION KINETICS
RESONANCE
SPACE GROUPS
SPECTRA
SPECTROSCOPY
SYNTHESIS
TECHNETIUM COMPLEXES
TRANSITION ELEMENT COMPLEXES
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
VOLTAMETRY