| Publication Type |
Journal Article |
| Title |
Diamine Bis(phenolate) as Supporting Ligands in Organoactinide(IV) Chemistry. Synthesis, Structural Characterization, and Reactivity of Stable Dialkyl Derivatives |
| Authors |
Elsa Mora Leonor Maria Biplab Biswas Clement Camp Isabel Cordeiro Santos Jacques Pecaut Adelaide Cruz José M. Carretas Joaquim Marçalo Marinella Mazzanti |
| Groups |
IOARC |
| Journal |
ORGANOMETALLICS |
| Year |
2013 |
| Month |
March |
| Volume |
32 |
| Number |
5 |
| Pages |
1409-1422 |
| Abstract |
The homoleptic compounds [U(salan-R-2)(2)] (R = Me (1), Bu-t (2)) were prepared in high yield by salt-metathesis reactions between UI4(L)(2) (L = Et2O, PhCN) and 2 equiv of [K-2(salan-R-2)] in THF. In contrast, the reaction of the tetradentate ligands salan-R-2 with UI3(THF)(4) leads to disproportionation of the metal and to mixtures of U(IV) [U(salan-R-2)(2)] and [U(salan-R-2)I-2] complexes, depending on the ligand to M ratio. The reaction of K(2)salan-Me-2 ligand with U(IV) iodide and chloride salts always leads to mixtures of the homoleptic bis-ligand complex [U(salan-Me-2)(2)] and heteroleptic complexes [U(salan-Me-2)X-2] in different organic solvents. The structure of the heteroleptic complex [U(salan-Me-2)I-2(CH3CN)] (4) was determined by X-ray studies. Heteroleptic U(IV) and Th(IV) chloride complexes were obtained in good yield using the bulky salan-Bu-t(2) ligand. The new complexes [U(salan-Bu-t(2))C-12(bipy)] (5) and [Th(salan-Bu-t(2))Cl-2(bipy)] (8) were crystallographically characterized. The salan-Bu-t(2) halide complexes of U(IV) and Th(IV) revealed good precursors for the synthesis of stable dialkyl complexes. The six-coordinated alkyl complexes [Th(salan-Bu-t(2))(CH2SiMe3)(2)] (9) and [U(salan-Bu-t(2))(CH2SiMe3)(2)] (10) were prepared by addition of LiCH2SiMe3 to the chloride precursor in toluene, and their solution and solid-state structures (for 9) were determined by NMR and X-ray studies. These complexes are stable for days at room temperature. Preliminary reactivity studies show that CO2 inserts into the An-C bond to afford a mixture of carboxylate products. In the presence of traces of LiCl, crystals of the dimeric insertion product [Th2Cl(salan-Bu-t(2))(2)(mu-eta(1):eta(1)-O2CCH2SiMe3)(2)(mu-eta(1):et a(2)-O2CCH2SiMe3)] (11) were isolated. The structure shows that CO2 insertion occurs in both alkyl groups and that the resulting carboxylate is easily displaced by a chloride anion. |
| DOI |
http://dx.doi.org/10.1021/om3010806 |
| ISBN |
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| Publisher |
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| Book Title |
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| ISSN |
0276-7333 |
| EISSN |
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| Conference Name |
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| Bibtex ID |
ISI:000316094900030 |
| Observations |
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