Reactions of "LnIx(SePh)3-x" (Ln = Dy, Ho) with elemental S/Se give (THF)14Ln10S6(Se 2)6I6. The compounds are composed of a Ln 6S6 double cubane core, with two twisted "Ln 2(SeSe)3" units condensed onto opposing rectangular sides of the Ln6S6 fragment. This deposition of Ln 2Se6 totally encapsulates the two central Ln's with chalcogen atoms (four S and four Se atoms), excluding neutral THF donors or iodides from the two primary coordination spheres. Reactions of Ln10 clusters with a stronger Lewis base result in fragmentation and, in the case of Ln = Er, the isolation of (py)6Er2(Se2)(S 0.8Se0.2)I2, with two Ln(III) ions spanned by E2- and (EE)2- ligands. The related homochalcogen dimers (py)6Ln2(Se2)(Se)Br2 (Ln = Ho, Yb) were prepared to establish that such molecules could be prepared rationally, and to confirm the isolability of E2- ligands coordinated to only two sterically unconstrained Ln ions.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry