The reaction between scandium terminal imido complexes and elemental selenium showed an unprecedented C-H bond selenation and the formation of an Sc-Se bond.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Thermolysis of 1-ethyl-3-methyl-1H-imidazolium tetrafluoroborate (1) and 1,3-dimethyl-1H-imidazolium hexafluorophosphate (3) under reduced pressure eliminates HF to furnish the BF3 and PF5 adducts of the corresponding Arduengo carbenes (2 and 4) in high yields. The intuitively anticipated imidazole N adducts with BF3 and/or PF5 arising from elimination of alkyl fluorides are not detected at all. These observations represent the first examples of a direct bond rearrangement of the type [C–H] + E–F → [C–E] + H–F (E = B, P). DFT computational studies suggest a single-step mechanism for the reaction 1 → 2 + HF. Lower yield thermolysis of a 1,2,3-trimethyl-1H-imidazolium hexafluorophosphate (11) into [(1,3-dimethyl-1H-imidazolium-2-yl)­methyl]­pentafluorophosphate (12) supports the generality of this transformation.

A novel half-sandwich Zr(IV) complex [g 5 :g 1 -N -C 5 (CH 3 ) 4 CH 2 CH 2 N(CH 3 ) 2 ]ZrCl 3 (6) together with zirconocene dichlorides [g 5 -C 5 (CH 3 ) 4 CH 2 CH 2 N(CH 3 ) 2 ][g 5 -C 5 (CH 3 ) 5 ]ZrCl 2 (4) and [g 5 -C 5 (CH 3 ) 4 CH 2 CH 2 N(CH 3 ) 2 ] 2 ZrCl 2 (5) have been prepared. Complex 6 has been isolated and characterized in three different forms, namely, as an adduct with THF 6a, an adduct with tetrahydrothiophene 6b, and a solvent-free form 6c. Molecular structures of complexes 4, 6b, and 6c have been established by X-ray diffraction analysis. Complex 6c has been shown to be a monomeric solvent-free half sandwich Zr(IV) complex. The dynamic behavior of complex 6a in a non-solvating medium (an equilibrium between 6a and 6c along with a degenerate interconversion of the Zr-C cp -CH 2 -CH 2 -N(CH 3 ) 2 -(Zr) pseudo-five-member metallacycle) have been studied by the variable-temperature 1 H and 13 C{ 1 H} NMR spectroscopy. The activation parameters for the degenerate five-member cycle interconversion have been elucidated.

A rare find: Soluble P3−‐containing rare‐earth‐metal coordination compounds have been synthesized. A P3−‐containing polymetallic yttrium iodide was obtained through PSi (or H) and PC bond cleavage, and this compound can be transferred into other P3−‐containing yttrium coordination compounds by metathesis reactions.