Actinide complexes amides

Actinide complexes with chelating ligands containing sulfur and amidic nitrogen donor atoms. U. Casellato, M. Vidali and P. A. Vigato, Coord. Chem. Rev., 1979, 28, 231-277 (181). 

Musikas, C., Condamines, N., Charbonnel, M.C., Hubert, H. 1989. Actinide complexes in solvent extraction. The Amide Type of Extractants, Actinides 89 Conference, Tashkent, USSR, September 24-29. CEA-CONF-10061. 

The actinides have a high degree of specificity for neutral and anionic oxygen-containing organic molecules. The actinide complexes with O -donor ligands that are most widely studied include alkoxides, aryloxides amide, carboxylates, and oxalates. Complexes with alcohols, ethers, esters, ketones, aldehydes, ketoenolates, and carbamates have also been reported. 

Aside from the neutral tris(amido)actinide complexes that have been prepared with sterically encumbering ligands as described, an alternate approach to the stabilization of trivalent actinide amides is the generation of anionic ate -type complexes. As an example, reaction of Ul3(THF)4 with excess KHNAr (Ar = 2,6-Pr 2CgH3) produces the anionic complex [K(THF)2]2[U(NHAr)5] which has been crystallographically characterized. ... 

Actinide complexes, 1129-1220 coordination numbers, 1131 geometry, 1131 kinetic stability, 1130 steric effects, 1130 Aciinide(III) complexes, 1131-1136 amides, 1133 ammines, 1131 antipyrine, 1134 aqua,1133... 

The hydroamination of olefins has been shown to occur by the sequence of oxidative addition, migratory insertion, and reductive elimination in only one case. Because amines are nucleophilic, pathways are available for the additions of amines to olefins and alkynes that are unavailable for the additions of HCN, silanes, and boranes. For example, hydroaminations catalyzed by late transition metals are thought to occur in many cases by nucleophilic attack on coordinated alkenes and alkynes or by nucleophilic attack on ir-allyl, iT-benzyl, or TT-arene complexes. Hydroaminations catalyzed by lanthanide and actinide complexes occur by insertion of an olefin into a metal-amide bond. Finally, hydroamination catalyzed by dP group 4 metals have been shown to occur through imido complexes. In this case, a [2+2] cycloaddition forms the C-N bond, and protonolysis of the resulting metallacycle releases the organic product. 

Semiempirical (INDO) approach. Zerner and coworkers developed the semiempirical, Intermediate Neglect of Differential Overlap (INDO) method for the calculation of electronic structures of actinide complexes (Cory et al. 1994). They presented ground-state resonance parameter sets for the actinide elements from Ac to Pu and applied the INDO parameters to the actinide halides, bis(cyclooctatetraenyl) actinide complexes M(COT)2 (M = Th, Pa, U, Np, Pu), the so-called actinocene and imide/amide complexes of uranium. The semiempirical approach is required for large systems, such as biological molecules containing actinide elements. 

A large number of urea and substituted urea complexes with actinide(IV) compounds are known in these the ligands are bonded to the metal via the carbonyl oxygen atom, and these complexes are therefore described in the section dealing with carboxylic add amide complexes (p. 1164). 

Table 35 Complexes of Actinide(IV) Compounds with Amides...

Table 36 Complexes of Actinide(IV) Compounds with Lactams, Antipyrine (2,3-Dimethyl-l-phenylpyrazol-5-one, ATP) and its Derivatives, and Dicarboxylic Acid Amides...

The extensive chemistry of amido complexes, and, more particularly, of alkylamido complexes, reveals that the planar form is almost invariably found, along with bridging amides (221). Much attention has been paid to the synthesis of metal amido complexes of early transition metals, lanthanides and actinides. The amido group, particularly where it is bulky, confers unusual low coordination numbers on the metals and can also produce materials with considerable kinetic stability toward attack by nucleophiles (42, 67). However, the relevance of this extensive and fascinating chemistry to nitrogen fixation is somewhat problematic. 

---