Structure and dynamics of complexes of the uranyl ion with nonamethylimidodiphosphoramide (NIPA). 2. NMR studies of complexes (UO/sub 2/(NIPA)/sub 2/X)(CIO/sub 4/)/sub 2/ with X = H/sub 2/O, MeOH, EtOH, or Me/sub 2/CO

Journal Article · Mon Mar 01 04:00:00 EST 1982 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00133a038· OSTI ID:5362758

Rodehueser, L; Rubini, P R; Bokolo, K; Delpuech, J J

The /sup 31/P and /sup 1/H spectra at -90/sup 0/C of the title uranyl complex ions (prepared as solutions of the solid perchlorates in inert anhydrous organic solvents (CH/sub 3/NO/sub 2/, CH/sub 2/Cl/sub 2/)) reveal a pentacoordinated arrangement of two symmetrically doubly bonded NIPA molecules and one solvent molecule about the uranyl group. In the case of (UO/sub 2/(NIPA)/sub 2/(EtOH))(ClO/sub 4/)/sub 2/, an intermolecular exchange between bound and free ethanol molecules is observed above -75/sup 0/C upon addition of ethanol to a solution of the complex. The observed rate law, k/sub inter/ = kK(EtOH)/(1 + K(EtOH) is accounted for by the existence of an outer-sphere complex (UO/sub 2//sup 2 +/(NIPA)/sub 2/(EtOH))EtOH in fast equilibrium (K) with the initial complex and free ethanol. The rate-determining step (k) consists of an outer-sphere to inner-sphere interchange of ethanol molecules. The thermodynamic and kinetic parameters are K(25/sup 0/C) = 15.8 dm/sup 3/ mol/sup -1/, k(25/sup 0/C) = 1.0 x 10/sup 4/s/sup -1/, ..delta..H and ..delta..H/sub inter//sup + +/ = -4.8 and 7.6 kcal mol/sup -1/, and ..delta..S and ..delta..S/sub inter//sup + +/ = 10.7 and -14.7 eu. A second exchange takes place at higher temperatures (above -30/sup 0/C) yielding full dynamic equivalence of the phosphorus nuclei of the coordinated NIPA molecules. The observed rate law k/sub intra/ = k/sub ex/(1 + K(EtOH)) reveals that the internal rearrangement of NIPA molecules occurs on the complex ion (UO/sub 2/(NIPA)/sub 2/(EtOH))/sup 2 +/ but not on the outer-sphere complex: k/sub ex/(25/sup 0/C) = 0.91 x 10/sup 3/s/sup -1/, ..delta..H/sub intra//sup + +/ = 10.6 kcal mol/sup -1/ and ..delta..S/sub intra//sup + +/ = -9.4 eu. Possible mechanisms for this exchange are discussed. 5 figures, 2 tables.

• Research Organization: Universite de Nancy, Cedex, France
• OSTI ID: 5362758
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 21:3; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACETONE
ACTINIDE COMPLEXES
ACTINIDE COMPOUNDS
ALCOHOLS
AMIDES
CHEMICAL EXPLOSIVES
CHEMICAL PREPARATION
CHLORINATED ALIPHATIC HYDROCARBONS
CHLORINE COMPOUNDS
COMPLEXES
DATA
ENTHALPY
ENTROPY
ETHANOL
EXPERIMENTAL DATA
EXPLOSIVES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
KETONES
LIGANDS
LOW TEMPERATURE
MAGNETIC RESONANCE
METHANOL
NITRO COMPOUNDS
NITROMETHANE
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SOLVENTS
ORGANOMETALLIC COMPOUNDS
OXYGEN COMPOUNDS
PERCHLORATES
PHYSICAL PROPERTIES
QUANTITY RATIO
RESONANCE
SOLVENTS
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TEMPERATURE DEPENDENCE
THERMODYNAMIC ACTIVITY
THERMODYNAMIC PROPERTIES
URANIUM COMPLEXES
URANIUM COMPOUNDS
URANYL COMPLEXES
URANYL COMPOUNDS
WATER