Covalency of Neptunium(IV) organometallics from /sup 237/Np Moessbauer spectra

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5541584

Karraker, D. G.

The isomer shifts in /sup 237/Np Moessbauer spectra arise from the shielding of neptunium's 6s orbitals by the inner 5f orbitals. In covalent bonding, ligand contributions to the 5f electron density increase the shielding, and the /sup 237/Np isomer shift reflects differences in bond character among covalently bonded ligands. The large difference in isomer shift (3.8 cm/sec) between ionic Np(IV) and Np(III) compounds permits a good determination of ligand bonding differences in Np(IV) organometallic compounds. The Moessbauer spectra for about 20 Np(IV) organometallic compounds, principally cyclopentadienyl (Cp) compounds of the general composition Cp/sub x/Np chi/sub 4-x/ (x = 1,2,3; chi = Cl, BH/sub 4/, /sup n/Bu, Ph, OR, acac), show both the differences in sigma bonding among the chi ligands, as well as the covalent effect of the Cp ligands.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.
• DOE Contract Number: EY-76-C-09-0001
• OSTI ID: 5541584
• Report Number(s): DP-MS-79-93; CONF-800303-8
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPOUNDS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
CHEMICAL BONDS
HEAVY NUCLEI
ISOTOPES
LIGANDS
MOESSBAUER EFFECT
NEPTUNIUM 237
NEPTUNIUM COMPOUNDS
NEPTUNIUM ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
RADIOISOTOPES
TRANSURANIUM COMPOUNDS
VALENCE
YEARS LIVING RADIOISOTOPES