Isothiocyanato complex of technetium(II). Spectroelectrochemical and single-crystal x-ray structural studies on trans-(Tc(DPPE)/sub 2/(NCS)/sub 2/)/sup 0/, where DPPE = 1,2-bis(diphenylphosphino)ethane
The air-stable technetium(II) complex trans-(Tc(DPPE)/sub 2/(NCS)/sub 2/)/sup 0/, where DPPE represents 1,2-bis(diphenylphosphino)ethane, has been characterized by single-crystal x-ray structural analysis refined to a conventional R factor of 0.069. Rose-colored crystals of this material, fw 1012.01, crystallize in the triclinic space group P1 with a = 21.384 (6) A, b = 12.878 (5) A, c = 9.549 (4) A, ..cap alpha.. = 71.51 (3)/sup 0/, ..beta.. = 81.94 (4)/sup 0/, and Z = 2. In this complex the technetium(II) center is approximately octahedrally coordinated with four equatorial P atoms at an average distance of 2.44 (1) A and two trans axial N-bonded NCS/sup -/ ligands at 2.04 (2) A. Spectroelectrochemical investigation of this complex shows that it undergoes reversible 1-equiv reduction to the Tc(I) anion and reversible 1-equiv oxidation to the Tc(III) cation, all three species being stable on the time scale of hours. The E/sup 0/' values (0.50 M tetraethylammonium perchlorate in N,N-dimethylformamide) for the Tc(III)/Tc(II) and Tc(II)/Tc(I) couples are 0.392 and -0.601 V vs. Ag/AgCl, respectively. Relative to chloro or bromo ligands, in the analogous trans-(Tc(DPPE)/sub 2/X/sub 2/)/sub /+/0/-/ (X = Cl, Br) complexes, the N-bonded NCS/sup -/ ligand markedly stabilizes the lower oxidation states. This effect and the dependence of the Tc-P bond length on the technetium oxidation state are discussed in terms of ..pi.. back-bonding. 25 references, 3 figures, 2 tables.
- Research Organization:
- Univ. of Cincinnati, OH
- DOE Contract Number:
- AC02-80EV10380
- OSTI ID:
- 6507291
- Journal Information:
- Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 23:18; ISSN INOCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ALKANES
ANTITHYROID DRUGS
AROMATICS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BOND ANGLE
BOND LENGTHS
CARBONIC ACID DERIVATIVES
CHEMICAL REACTIONS
CHEMISTRY
COHERENT SCATTERING
COMPLEXES
CORRELATIONS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DATA
DATA ANALYSIS
DIFFRACTION
DIMENSIONS
DISTANCE
DRUGS
ELECTROCHEMISTRY
EXPERIMENTAL DATA
HORMONE ANTAGONISTS
HOURS LIVING RADIOISOTOPES
HYDROCARBONS
INFORMATION
INTERATOMIC DISTANCES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LATTICE PARAMETERS
LENGTH
LIGANDS
MATHEMATICAL MODELS
MOLECULAR STRUCTURE
MONOCRYSTALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDATION
PHOSPHINES
PHOSPHORUS COMPOUNDS
RADIOISOTOPES
REDUCTION
SCATTERING
STABILITY
STRUCTURAL CHEMICAL ANALYSIS
TECHNETIUM 99
TECHNETIUM COMPLEXES
TECHNETIUM ISOTOPES
THIOCYANATES
TIME DEPENDENCE
TRANSITION ELEMENT COMPLEXES
TRICLINIC LATTICES
VOLTAMETRY
X-RAY DIFFRACTION
YEARS LIVING RADIOISOTOPES