Synthesis and Characterization of Divalent Samarium and Thulium N,N-Dimethylaminodiboranates

Abstract

The syntheses and molecular structures of new Sm II and Tm II N,N-dimethylaminodiboranate (DMADB) complexes are described. Treating SmI 2 (THF) 2 with Na(H 3 BNMe 2 BH 3 ) in THF results in the formation of Sm(H 3 BNMe 2 BH 3 ) 2 (THF) 3 (1), which can be readily converted to Sm(H 3 BNMe 2 BH 3 ) 2 (DME) 2 (DME = 1,2-dimethoxyethane) or Sm-(H 3 BNMe 2 BH 3 ) 2 (diglyme) by exchange with the corresponding ether. We also show that Sm(H 3 BNMe 2 BH 3 ) 2 (THF) 3 can be prepared by reduction of the Sm III compound Sm(H 3 BNMe 2 BH 3 ) 3 (THF) with KC 8 and that addition of 18-crown-6 to this reaction mixture results in the formation of the Sm II compound Sm(H 3 BNMe 2 BH 3 ) 2 (18-crown-6). In a similar fashion, two new Tm II complexes have been synthesized: treatment of TmI 2 in THF with Na(H 3 BNMe 2 BH 3 ) results in the formation of Tm(H 3 BNMe 2 BH 3 ) 2 (THF) 2 and Tm(H 3 BNMe 2 BH 3 ) 2 (THF) 3 , which form a cocrystal. IR data and elemental analyses are reported for all the new compounds, as are their crystal structures. 1 H and 11 B NMR data are provided where available.

Stability and Solution Behavior of [(dpp-Bian)Ln] and [(dpp-Bian)LnX] (Ln = Yb, Tm, or Dy; X = I, F, or N3)

“…Since then, the field has expanded considerably, and finally, molecular representatives for all divalent lanthanides (except for Pm) were isolated . Despite the high reactivity of divalent lanthanide centers, several thulium­(II) derivatives of bis­(silyl)­amide, borohydride, cyclopentadienyl, and dimethylaminodiboranate ligands were isolated. They found use in hydrocarbon and ketone coupling reactions and small molecule activations .…”