Yj. Zhang et al., Synthesis, spectroscopic, and X-ray crystallographic characterisation of thorium(IV) and uranium(IV) malonato and substituted malonato compounds, POLYHEDRON, 19(14), 2000, pp. 1757-1767
With doubly protonated piperazine or ethylenediamine as cations, eight Th(I
V) malonato or substituted malonato complexes have been prepared and charac
terised by elemental analysis, thermal analysis, IR and C-13 CPMAS NMR spec
troscopy. One polymeric U(IV) malonato complex has also been prepared and c
haracterised by elemental analysis, thermal analysis and IR spectroscopy. (
C4H12N2)(2)[Th(C3H2O4)(4)]. H2O (2), (C2H10N2)(2)[Th(C3H2O4)(4)(H2O)] (3),
(C4H12N2)(2)[Th(C4H4O4)(4)]. 2H(2)O (4), (C2H10N2)(2)[Th(C5H6O4)(4)]. 5H(2)
O (6) and [U(C3H2O4)(2)(H2O)(3)](n) (9) have been further characterised by
single-crystal X-ray diffraction. Two types of monomeric anion structure ar
e identified in the Th compounds: four 1,5-bidentate ligands in a distorted
square antiprismatic geometry, giving coordination number (CN) 8; and four
1,5-bidentate ligands and a coordinated H2O molecule in a capped square an
tiprismatic geometry, giving CN 9. The U compound has a 3D polymeric struct
ure, with U in an approximately capped square antiprismatic geometry, achie
ving CN 9 from two 1,5-bidentate ligands, each of which also bridges throug
h a carbon yl oxygen to an adjacent U centre, and three H2O molecules. In t
he crystallographically-characterised Th compounds, the Th-O and C-O distan
ces are correlated with the carbonyl resonance positions in the C-13 CPMAS
NMR spectra, allowing prediction of structural types in the non-crystalline
compounds. (C) 2000 Elsevier Science Ltd. All rights reserved.