Sequestering uranium from seawater: binding strength and modes of uranyl complexes with glutarimidedioxime.
Glutarimidedioxime (H(2)A), a cyclic imide dioxime ligand that has implications in sequestering uranium from seawater, forms strong tridentate complexes with UO(2)(2+). The stability constants and the enthalpies of complexation for five U(VI) complexes were measured by potentiometry and microcalorimetry. The crystal structure of the 1 : 2 metal-ligand complex, UO(2)(HA)(2)·H(2)O, was determined. The re-arrangement of the protons of the oxime groups (-CH=N-OH) and the deprotonation of the imide group (-CH-NH-CH-) results in a conjugated system with delocalized electron density on the ligand (-O-N-C-N-C-N-O-) that coordinates to UO(2)(2+)via its equatorial plane.
Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720, USA.
Guoxin
G
Tian
Simon J
SJ
Teat
Zhiyong
Z
Zhang
Linfeng
L
Rao