Structure and dynamics of complexes of the uranyl ion with nonamethylimidodiphosphoramide (NIPA). 1. NMR study of the complex (UO/sub 2/(NIPA)/sub 3/)(CIO/sub 4/)/sub 2/

Journal Article · Wed Apr 01 04:00:00 EST 1981 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic50218a009· OSTI ID:6341024

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

The /sup 31/P(/sup 1/H) spectrum at -90/sup 0/C of the uranyl complex ion UO/sub 2/(NIPA)/sub 3//sup 2 +/, prepared as a solution of the solid perchlorate in inert anhydrous organic solvents (CH/sub 3/NO/sub 2/, CH/sub 2/Cl/sub 2/), reveals a pentacoordinated arrangement of two symmetrically doubly bonded and one singly bonded (NMe/sub 2/)/sub 2/P(O)NMeP(O)(NMe/sub 2/)/sub 2/(NIPA) molecules about the uranyl group. A fast intramolecular exchange (for t > -60/sup 0/C) yields a full dynamic equivalence of all the phosphorus nuclei of the complex above 30/sup 0/C. An intermolecular exchange between bound and free NIPA molecules is observed above 100/sup 0/C upon addition of NIPA to the solutions. Both processes are independent of the amount of free NIPA. Kinetic parameters are k(25/sup 0/C) = 1.3 x 10/sup 5/ and 3.4 x 10/sup -3/s/sup -1/, ..delta..H = 11.8 and 18.2 kcal mol/sup -1/, and ..delta..S = 4.5 and -9.1 cal K/sup -1/mol/sup -1/, for the intra- and intermolecular processes, respectively. These procedures are shown to proceed via a common first step, involving the breaking of a metal-ligand bond of one of the two bidentate NIPA molecules, followed by either the internal return of the tetracoordinated intermediate to the initial complex (fast) or the loss of a NIPA molecule (slow).

• OSTI ID: 6341024
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 20:4; 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
ACTINIDE COMPLEXES
AMIDES
COMPLEXES
DATA
EXPERIMENTAL DATA
INFORMATION
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOMETALLIC COMPOUNDS
RESONANCE
URANIUM COMPLEXES
URANYL COMPLEXES