Eine elektrochemische und strukturelle Studie an den Eisensilylamiden Fe[N(SiMe₃)₂]₂ und Fe[N(SiMe₃)₂]₃ / An Electrochemical and Structural Study of the Iron Silylamides Fe[N(SiMe₃)₂]₂ and Fe[N(SiMe₃)₂]₃

Abstract

The bis(trimethyl)silylamido complex Na (THF)

Divalent Transition Metal Silylamide Ate Complexes

“…Comparing the structures of the iron(II) complexes 1 and 2 (Figures 1 and 2) with that of the previously reported (thf)NaFe[N(SiMe 3 ) 2 ] 3 ( D , Scheme ),15 one observes that the AM–N bond lengths are considerably longer for the sodium‐containing compound (2.445 Å, the bond lengths were determined using Mercury 3.1),28 in accordance with its larger ionic radius compared to that of lithium(I). The Li1–N distances of the thf‐solvated complex 2 are longer than those of the donor‐free complex 1 (cf.…”

“…Donor‐free ate complexes with structures similar to that of iron complex 1 (Figure 1) are known for divalent main group metals and rare‐earth metals ( H – N , Scheme ),19a,25 but this is the first example with a transition metal. The thf‐containing mixed sodium/iron(II) complex (thf)NaFe[N(SiMe 3 ) 2 ] 3 has been obtained before ( D , Scheme ) 15. It surprisingly occurred alongside the disilane t Bu 3 SiSi t Bu 3 when the supersilanide Na(thf) 2 [Si t Bu 3 ]26 was treated with {Fe[N(SiMe 3 ) 2 ] 2 } 2 20…”

“…Table 1). The Fe1–N1 bond lengths in 1 and 2 are shorter than the Fe1–N2 bonds, whereas those in symmetric (thf)NaFe[N(SiMe 3 ) 2 ] 3 are of the same length (2.043 Å) 15. Although both bonds, Fe1–N1 and Fe1–N2, of 2 are longer than the Fe–N bridge bonds in (thf)NaFe[N(SiMe 3 ) 2 ] 3 , for 1 only Fe1–N2 is longer while Fe1–N1 is shorter.…”

“…The dynamic magnetic properties of dimeric {Li(bta)Fe[N(SiMe 3 ) 2 ] 2 } 2 (bta = benzotriazolide) have also been studied, and there is very weak antiferromagnetic exchange between the two iron(II) centers 12. Ate complexes in which the transition metal and alkali metal ions are connected through bridging silylamido ligands are represented by Na[N(SiMe 3 ) 2 ] 2 Mn(CH 2 SiMe 3 ),13 (thf)LiMn[N(SiMe 3 ) 2 ] 3 (thf = tetrahydrofuran),14 and (thf)NaFe[N(SiMe 3 ) 2 ] 3 ( C and D , Scheme ) 15…”

Reduction of 2,2′-Bipyridine by Quasi-Linear 3d-Metal(I) Silylamides—A Structural and Spectroscopic Study

“…To further substantiate the presence of a bipyridine radical anion in the complexes 1-4 on a structural level, we compared their structural features to those of their neutral counterparts, [M II (hmds) 2 (bipy)]. For the chromium (5) [42], manganese (6) [43] and iron (7) [43] complexes the synthesis and solid state structures were already described in the literature. As further analysis of their spectroscopic properties was lacking, their synthesis was reproduced by the reaction of the respective hmds salt with 2,2 -bipyridine in Et 2 O. Analogously, the missing cobalt derivative 8 was obtained as a dark red crystalline solid in moderate yield (Scheme 3; Figure 2, left).…”