Practical synthetic routes to solvates of U(OTf)3: X-ray crystal structure of [U(OTf)3(MeCN)3]n, a unique U(III) coordination polymer.

The reaction of UH3 or U metal with triflic acid results in the formation of a mixture of species including U(OTf)4 and leads to the reproducible isolation of the mononuclear U(IV) hydroxo complex [U(OTf)3(OH)(py)4] (1) and the U(IV) dinuclear mu-oxo-complex [{U(OTf)2(py)3}2{mu-O}{mu-OTf}2] (2). The X-ray crystal structures of these complexes have been determined. Analytically pure complex 1 can be prepared in a 17-27% yield providing a good precursor for the synthesis and study of the reactivity of the hydroxo complexes with different coordination environments.

Comparative structural studies of iodide complexes of uranium(III) and lanthanide(III) with hexadentate tetrapodal neutral N-donor ligands.

The syntheses, the solution structures, and the crystal structures of the two new tetrapodal N-donor ligands N,N,N',N'-tetrakis(2-pyrazylmethyl)-1,3-trimethylenediamine (tpztn), 1, and N,N,N',N'-tetrakis(2-pyrazylmethyl)-trans-1,2-cyclohexanediamine (tpzcn), 2, are described. Two different geometric isomers of the cation [La(tpztn)I(2)](+) were isolated in which the ligand adopts two different conformations leading to strong differences in the metal-ligand bond distances. The crystal structure of isostructural complexes of La, U, Ce, and Nd were determined by X-ray diffraction studies for the ligands tpztn and tpzcn.

Structures of the radical P[N(SiMe3)2](NPri2), its dimer, cation and chloro derivative.

Treatment of PCl[N(SiMe3)2](NPri2) (1) with potassium-graphite in thf afforded the colourless, crystalline diphosphine [P[N(SiMe3)2](NPri2)]2 (2) in good yield. Sublimation of 2 in vacuo yielded the yellow phosphinyl radical P[N(SiMe3)2](NPri2) (3), which upon cooling reverted to 2; the latter in C6D6 at 298 K was a mixture of rac and meso diastereoisomers. The yellow, crystalline phosphenium salt [P[N(SiMe3)2](NPri2)][AlCl4] (4) was obtained from 1 and 1/2Al2Cl6 in CH2Cl2.

Synthesis and P-P cleavage reactions of [P(X)X']2; X-ray structures of [Co[P(X)X'](CO)3] and P4[P(X)X']2[X = N(SiMe3)2, X'= NPri2].

Treatment of P(X)(X')Cl with KC8 gave the crystalline diphosphine [P(X)X']2 (1) which dissociated reversibly into the phosphinyl radical *P(X)X' (2), a plausible intermediate in the reaction of with [Cr(CO)6], [Co(NO)(CO)3] or P4, yielding [Cr[P(X)X']2(CO)3] (3), [Co[P(X)X'](CO)3] (4), or 1,4-P4[P(X)X']2 (5); the P(X)X' substituent is pyramidal at P in but planar in [X = N(SiMe3)2, X'= NPri2].