Bis(dimethylsilyl)amide and bis(dimethylphenylsilyl)amide complexes of the divalent transition metals chromium, manganese, and cobalt were synthesized. Dimeric, donor-free {Mn[N(SiHMe2)2]2}2 could be obtained via two different pathways, a salt metathesis route (utilizing MnCl2(thf)1.5 and LiN(SiHMe2)2) and a transsilylamination protocol (utilizing Mn[N(SiMe3)2]2(thf) and HN(SiHMe2)2). Addition of 1,1,3,3-tetramethylethylendiamine (tmeda) to {Mn[N(SiHMe2)2]2}2 yielded the monomeric adduct Mn[N(SiHMe2)2]2(tmeda). The syntheses of Cr[N(SiHMe2)2]2(tmeda), Co[N(SiMe3)2][N(SiHMe2)2](tmeda), and Co[N(SiHMe2)2]2(tmeda) were achieved by transsilylamination from Cr[N(SiMe3)2]2(tmeda) and {Co[N(SiMe3)2]2}2(μ-tmeda), respectively. Bis(dimethylphenylsilyl)amide complexes Mn[N(SiMe2Ph)2]2, Cr[N(SiMe2Ph)2]2, and Co[N(SiMe2Ph)2]2(thf) were obtained via salt metathesis employing MCl2(thf)x (M = Cr, Mn, Co) with equimolar amounts of LiN(SiMe2Ph)2 in n-hexane. Treatment of CrCl2 with LiN(SiMe2Ph)2 in thf gave Cr[N(SiMe2Ph)2]2(thf)2, featuring an almost square planar trans-coordination. All complexes were examined by elemental analyses, DRIFT and UV-vis spectroscopy, as well as X-ray structure analysis, paying particular attention to secondary M---SiH β-agostic and M---π(arene) interactions. Magnetic moments were determined by Evans' method.

Dimetallic ate complexes were synthesized from the divalent transition metal silylamide complexes {Fe[N(SiMe3)2]2}2, Cr[N(SiMe3)2]2(thf), Co[N(SiMe3)2]2(thf)2, and {Mn[N(SiHMe2)2]2}2 (thf = tetrahydrofuran) by the addition of the corresponding lithium or sodium silylamide salt. Accordingly, donor‐free LiFe[N(SiMe3)2]3 and NaMn[N(SiHMe2)2]3 as well as thf‐coordinated (thf)NaCr[N(SiMe3)2]3 and (thf)NaCo[N(SiMe3)2]3 were obtained. The thf‐containing mixed iron(II)/lithium bis(trimethylsilyl)amide complex (thf)LiFe[N(SiMe3)2]3 was synthesized by the simple addition of thf to the donor‐free complex LiFe[N(SiMe3)2]3. All of the complexes were characterized by IR spectroscopy and elemental analysis, and the effective magnetic moments in solution were determined by the Evans method. The solid‐state structures of these bis(trimethylsilyl)amido‐derived complexes were additionally determined by X‐ray crystallography.

Ab initio calculations on the octahedral dysprosium aluminate complex [Dy(AlMe4)3] (1) predict weak SMM properties. Dynamic magnetic susceptibility measurements on 1 confirm the theoretical predictions, revealing fast relaxation of the magnetization via quantum tunnelling.

The alkaline earth metal alkyl complexes [Ba(AlEt(4))(2)](n) and Mg(AlMe(4))(2) were directly grafted onto periodic mesoporous silica MCM-41, which had been dehydroxylated at 270 °C (specific surface area a(s): 1023 m(2) g(-1); pore volume V(p): 1.08 cm(3) g(-1); main pore diameter 3.4 nm). Alternatively, barium alkyl surface species were generated by sequential grafting of MCM-41 with Ba[N(SiHMe(2))(2)](2)(thf)(4) and AlEt(3) to yield the hybrid material AlEt(3)@Ba[N(SiHMe(2))(2)](2)(thf)(4)@MCM-41. For a better understanding of the surface chemistry, AlEt(3)@MCM-41 was also accessed. All hybrid materials were analyzed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, elemental analysis, nitrogen physisorption, and solid-state NMR spectroscopy; this clearly revealed distinct surface chemistry for the alkylaluminate-treated materials [Ba(AlEt(4))(2)]@MCM-41 and Mg(AlMe(4))(2)@MCM-41. In an attempt to mimic the surface chemistry, the organometallic precursors were treated with HOSi(OtBu)(3). The reaction of equimolar amounts of {Ba[N(SiHMe(2))(2)](2)}(n) and HOSi(OtBu)(3) produced a mixed silylamido/siloxide cluster of Ba(3)[OSi(OtBu)(3)](3)[N(SiHMe(2))(2)](3) with bridging-only siloxide ligands as well as one bridging and two terminal silylamido ligands. The Schlenk equilibrium was found to govern the [Ba(AlEt(4))(2)](n)-HOSi(OtBu)(3) and Mg(AlMe(4))(2)-HOSi(OtBu)(3) reactions, leading to the isolation of complexes of [Ba(AlEt(4))(2) (toluene)](2) and Mg[OSi(OtBu)(3))](2)(AlMe(3))(2), respectively. Allowing for a donor-induced cleavage of Mg(AlMe(4))(2), the reaction of [MgMe(2)] with one or two equivalents of HOSi(OtBu)(3) was studied. While putative Mg[OSi(OtBu)(3)](Me) and Mg[OSi(OtBu)(3)](2) could not be crystallized from the reaction mixtures, cluster complexes Mg(5)(O)[OSi(OtBu)(3)](5)Me(3) and Mg(4)(OH)(2)[OSi(OtBu)(3)](6) could be unambiguously identified by X-ray crystallography.

Heteroleptic ate complexes of the type K[M{N(SiMe3)2}2{OSi(OtBu)3}] (M = Cr, Mn, Co) were synthesized by adding one equivalent of the potassium salt KOSi(OtBu)3 to the bis(trimethylsilyl)amide precursors [Cr{N(SiMe3)2}2(thf)2], [Mn{N(SiMe3)2}2(thf)] and [Co{N(SiMe3)2}2(thf)], respectively. Surprisingly, the reaction of CrCl3(thf)3 with only two equivalents of KOSi(OtBu)3 yielded the homoleptic ate complex K[Cr{OSi(OtBu)3}4]. The compounds were characterized by elemental analysis and DRIFT spectroscopy as well as X-ray crystallography.