Christian Drost

Thermally Stable Heterobinuclear Bivalent Group 14 Metal Complexes Ar2M−Sn[1,8‐(NR)2C10H6] (M=Ge, Sn; Ar=2,6‐(Me2N)2C6H3; R=CH2tBu)

The first thermally robust Ge(II) -Sn(II) compound 1 and the structurally characterized Sn(II) -Sn(II) analogue 2, which maintain their structural integrity in solution, were obtained by treating MAr2 (M=Ge, Sn; Ar=2,6-(Me2 N)2 C6 H3 ) with Sn[1,8-(NR2 )2 C10 H6 ] (R=CH2 tBu). On the basis of structural and spectroscopic data, the M-Sn bond is regarded as the interaction of a MAr2 donor with an Sn[1,8-(NR2 )2 C10 H6 ] acceptor.

Dilithium diamides [{Li(OC4H8)}2{C20H12(NR)2}](R = SiMe3 or CH2But) derived from R-, S- or R,S-2,2′-diamino-1,1′-binaphthyl derivatives

The dilithium diamides [{Li(thf)}2{C20H12(NR)2}](R = SiMe31 or CH2But2, thf = tetrahydrofuran) were prepared from R,S-2,2′-diamino-1,1′-binaphthyl, C20H12(NH2)2, via C20H12[N(H)SiMe3]2 or C20H12[NHC(O)But]2 and C20H12[N(H)CH2But]2, respectively, and were transformed into SiCl2[C20H12(NR)2] by treatment with SiCl4. The crystal structures of 1 and 2 were determined. They are monomers, having a Li(1)N(1)Li(2)N(2) buckled ring, with Li(1)–N(2)ca. 0.2 A shorter than Li(1)–N(1), the two groups R cis to one another, and N(1)–C(1)η2 bonded to Li(1). The R and S enantiomers were similarly prepared and their optical stability was demonstrated by their hydrolysis to R- and S-C20H12(NH2)2, respectively. Evidence is provided for the structures of [M{[graphic omitted](SiMe3)]2}](M = Ge or Sn), obtained by conversion of the stannylene into the crystallographically characterised [{Sn[([graphic omitted]20H12](µ-O)}3].

Thermisch stabile Heterozweikernkomplexe mit zweiwertigen Metallzentren der Gruppe 14: Ar2M−Sn[1,8-(NR)2C10H6] (M = Ge, Sn; Ar = 2,6-(Me2N)2C6H3; R = CH2tBu)

In Losung erhalten bleiben die Strukturen der ersten thermisch stabilen GeII-SnII-Verbindung 1 sowie des strukturell charakterisierten SnII-SnII-Analogons 2. Diese Verbindungen wurden durch Umsetzung von MAr2 (M = Ge, Sn; Ar = 2,6-(Me2N)2C6H3) mit Sn[1,8-(NR2)2C10H6] (R = CH2tBu) synthetisiert. Den Strukturdaten und spektroskopischen Ergebnissen zufolge resultiert die M-Sn-Bindung aus der Wechselwirkung zwischen MAr2 als Donor und Sn[1,8-(NR2)2C10H6] als Acceptor.

The novel, chelating C, N-bidentate 2,6-bis(dimethylamino)phenylligand (R-), showing ambidentate N,N′-character inM(R)2 (M = Ge, Sn, Pb) and Sn(R)X [X =N(SiMe3)2, CH(SiMe3)2,Cl]

Treatment of MCl 2 or [Sn(µ-Cl){N(SiMe 3 ) 2 }] 2 with [Li(µ-R)] 3 [R = C 6 H 3 (NMe 2 ) 2 -2,6] under mild conditions and in appropriate stoichiometry affords MR 2 (M = Ge 1, Sn 2, Pb 3) or Sn(R)X [X = N(SiMe 3 ) 2 4, Cl 6], while 4 or 6 with LiCH(SiMe 3 ) 2 give SnR[CH(SiMe 3 ) 2 ] 5; compounds 1–6 are characterised by their multinuclear NMR and MS spectra and 1–3 by X-ray crystal structures.

Synthesis and characterisation of the first stable, heteroleptic silylstannylenes†

Treatment of the silylene Si[C6H4(NCH2But)2-1,2] with SnAr2 or SnAr[N(SiMe3)2] yields the thermally stable (silyl)stannylene SnAr[Si{C6H4(NCH2But)2-1,2}X] [X = Ar 1 or N(SiMe3)2 2], having δ [119Sn{1H}] 412 [1J(29Si–117/119Sn) 715/749 Hz] (1) and δ 621 (2); crystalline 1 has a V-shaped Si–Sn–C skeleton, l(Sn–Si) = 2.636(2) A and two remote Sn···N contacts, av. 2.75 A (to one NMe2 group of each of the aryl groups).

Lithium- [N-di-tert-butylfluorsilyl-N′,Ν′-dimethyl-hydrazid] -Synthese, Kristallstruktur und Reaktivität / Lithium (N-di-tert-butylfluorosilyl-N′,N′-dimethyl)hydrazide -Synthesis, Crystal Structure and Reactivity

Di-tert-butyldifluorosilane reacts with N-lithium-N′,N′-dimethylhydrazine in a molar ratio 1:1 to yield the N-di-tert-butylfluorosilyl-N′,N′-dimethylhydrazine 1. The lithium derivative of 1 (2) forms a dimer with the nitrogen atoms coordinated “side-on” to the lithium atoms. The silylation with Me3SiCl gives product 3. Heating 2 in a vacuum leads to the cyclodisilazane derivative 4. A bis(hydrazino)fluoroborane (5) is obtained in the reaction of 2 with trifluoroborane-etherate.