Mono- and ditopic lithium ferrocenylhydridoborates Li[FcBH(3)] (2) and Li(2)[H(3)B-fc-BH(3)] (4) have been synthesized from FcB(OMe)(2)/(MeO)(2)B-fc-B(OMe)(2) and Li[AlH(4)] (Fc = ferrocenyl; fc = 1,1'-ferrocenylene). X-ray quality crystals were grown from OEt(2). Depending on the amount of Li(+)-coordinated solvent molecules, dimeric (2(OEt(2))(2)) or tetrameric (2(OEt(2))) aggregates are observed in the solid state. The ditopic derivative 4 crystallizes as two different macrocyclic dimers (4(OEt(2))(5) and 4(OEt(2))(6)) in the unit cell. Each of the four aggregates is held together mainly by RBH(3)-eta(2)-Li bonds. Addition of Me(3)SiCl to 2 or 4 generates the corresponding boranes FcBH(2) (5) and H(2)B-fc-BH(2) (6), which can be trapped by adduct formation with NMe(2)Et or SMe(2). In contrast, when OEt(2) is present as the sole Lewis basic donor, no stable ether adducts are obtained, but condensation takes place leading to Fc(2)BH (10) and the novel borane polymer [-fcB(H)-](n) (9), respectively. In situ generation of FcBH(2) (5) in the presence of cyclohexene gives Fc(2)BCy and BCy(3) but no FcBCy(2), thereby indicating that 5 undergoes condensation to 10 more quickly than hydroboration of an internal olefin can occur (Cy = cyclohexyl). Fc(2)BH (10) was further studied as a model system for the optimization of modification reactions of polymer [-fcB(H)-](n) (9). Hydroboration of PhCCH or tBuCCH with 10 proceeds smoothly and quantitatively to give the corresponding vinylboranes Fc(2)B(CH horizontal lineCHR) (11(Ph), R = Ph; 11(tBu), R = tBu), which were fully characterized. In a similar manner, the polymeric borane 9 was successfully transformed into ferrocenylborane polymers [-fcB(CH horizontal lineCHR)-](n) (12(Ph), R = Ph; 12(tBu), R = tBu) that contain vinyl groups attached to boron. The structures of polymers 12 were confirmed by NMR and IR spectroscopy and mass spectrometry. The MALDI-TOF spectra of 12(Ph) and 12(tBu) showed patterns of equidistant peaks with peak separations that are consistent with the masses of the expected repeating units of each of the polymers. The absorption maxima in the UV-vis spectra of polymers 12 are significantly red-shifted in comparison to the dimeric model systems 11.

Inhaltsu È bersicht. Das Natriumsilanid tBu 2 PhSiNa la È sst sich bei erho È hter Temperatur durch Einwirken von Na-Metall auf das Bromsilan tBu 2 PhSiBr in organischen Lo È sungsmitteln wie n-Heptan bzw. Ethern nahezu quantitativ gewinnen. Erstmals wurde mit tBu 2 PhSiNa ein Silanid, welches im Festko È rper ein kettenfo È rmiges Koordinationspolymer bildet, strukturell charakerisiert. Hierbei sind die tBu 2 PhSiNa-Einheiten durch g 6 Natrium±Phenyl-Kontakte miteinander verbru È ckt. Durch Oxidation mit Tetracyanethylen la È sst sich tBu 2 PhSiNa in das Disilan tBu 2 PhSi±SiPhtBu 2 u È berfu È hren.The Sodium Silanide tBu 2 PhSiNa: Synthesis, Properties, Structure Analysis ± a Synthetic Pathway to Introduce the tBu 2 PhSi-Ligand Abstract. The sodium silanide tBu 2 PhSiNa is easily obtained by the reaction of sodium metal with tBu 2 PhSiBr at elevated temperatures in n-heptane, THF or dibutylether. An X-ray crystal structure analysis reveals, that the sodium silanide 3 contains chains of tBu 2 PhSiNa units with g 6 sodium±phenyl-contacts. Oxidation of tBu 2 PhSiNa with TCNE proceeds with formation of the disilane tBu 2 PhSi±SiPhtBu 2 .

The alkali metal silanides tBu2PhSiM (M = Li, Na, K) are quantitatively accessible from the reaction of tBu2PhSiBr with alkali metals in heptane, tetrahydrofuran, and benzene at moderately elevated temperature. In contrast to the polymer structure of unsolvated tBu2PhSiNa, the solvated di‐tert‐butylphenylsilanides tBu2PhSiNa(THF), tBu2PhSiK(C6H6), tBu2PhSiK(THF), and tBu2PhSiK(THF)2 possess a novel feature in their crystal structures with a dimeric arrangement of tBu2PhSiM units via π interaction between the tBu2PhSi group and the alkali metal centers. The alkali metal siloxides tBu2PhSiOM (M = Li, Na, K) can be synthesized almost quantitatively from tBu2PhSiM (M = Li, Na, K) with N2O in tetrahydrofuran at —78 °C. Single crystals of the silanol tBu2PhSiOH have been obtained from the protolysis of tBu2PhSiONa with (NH4)2SO4.

X-ray quality crystals of Zn[N(SiMe 3 ) 2 ] 2 (monoclinic, P2 1 /c) are obtained by sublimation of the zinc amide Zn[N(SiMe 3 ) 2 ] 2 at Ϫ30°C in vacuo (300 torr). According to the result of the X-ray Nachdem bereits 1849 Diethylzink und wenig später die erste Zink-Stickstoffverbindung durch Frankland [1] synthetisiert wurden, gelang es erst mehr als 100 Jahre danach, 1983, erstmals ein molekulares Zinkamid strukturell zu charakterisieren [2]. In der Folgezeit wurden Zinkamide mit den Strukturen 1-6 bekannt gemacht (Abb.