Darstellung und Molekülstruktur von 1,3-Diaza-2,4-disilacyclobutanen

Synthesis and Molecular Structures of 1,3-Diaza-2,4-disilacyclobutanes Lithio-aminofluorosilanes are obtained from the reaction of aminofluorosilanes with butyllithium. The thermal elimination of LiF from lithio-aminofluorosilanes affords a simple synthetic route to four-membered silicon-nitrogen rings. The structures of 1,3-bis(3,5-dimethylphenyl)-2,2,4,4-tetramethyl- and 2,4-di-tert-butyl-2,4-difluoro-1,3-bis(2,4,6-trimethylphenyl)-1,3-diaza-2,4-disilacyclobutanes have been determined by X-ray diffraction.     

Synthese und Molekülstruktur chiraler Bis(1,3,2‐dioxaphospholane)

Synthesis and Molecular Structure of Chiral Bis(1,3,2‐dioxaphospholanes) Bisphosphites of the general type C₂O₂POC_nOPO₂C₂ containing chiral building blocks both in the five‐membered C₂O₂P rings and in the OC_nO bridge were prepared from 2‐chloro‐1,3,2‐dioxaphospholanes and chiral diols in the presence of a base. The molecular structure of compound 10 , which was obtained from 2‐chloro‐(4R,5R)‐4,5‐dimethyl‐1,3,2‐dioxaphospholane and (R)‐1,1′‐binaphthalin‐2,2′‐diol, was determined by X‐ray crystallography.     

Kristall- und Molekülstruktur von Tetra-n-butylammonium-N-methyl-N-thioformyldithiocarbamat

Crystal and Molecular Structure of Tetra-n-butylammonium N-Methyl-N-Thioformyl Dithiocarbamate [N(n-C₄H₉)₄][S₂C? N(CH₃)? CS? H] crystallizes in the triclinic space group P1 (Z = 2) with cell dimensions (?45°C) a = 9.185(2) Å, b = 10.263(3) Å, c = 13.301(3) Å, α = 101.73(2)°, ß = 99.59(2)°, γ 100.57(2)°. The crystal structure was solved by means of direct methods and refined to a conventional reliability index R = 0.066 (R_ω = 0.070). 5945 independent intensities being measured.     

Synthese und Molekülstruktur zweier 1-Sila-3-alanata-cyclobutan-Derivate mit AlC2Si-Heterozyklus

Synthesis and Molecular Structure of Two 1-Sila-3-alanata-cyclobutane Derivatives with Four-membered AlC₂Si-Heterocycles The C? H acidic bis(trimethylsilyl)methyl compounds Me₃C? AlR₂ und Me₃C? CH₂? AlR₂ (R ? CH(SiMe₃)₂) are deprotonated by treatment with the sterically high shielded base LiCH(SiMe₃)₂ in the presence of 1,3,5-trimethylhexahydrotriazinane. The deprotonation occurs at a methyl group of one of the element-organic substituents, and the formed carbanions are stabilized by coordination to the unsaturated Al atoms yielding four-membered heterocycles. Both products were characterized by a crystal structure determination each showing bent ring systems.     

Die Kristall- und Molekülstruktur des Hexaphenyldiplumbans

Crystal and Molecular Structure of Hexaphenyldiplumbane The crystal and molecular structure of (C₆H₅)₆Pb₂ (space group and lattice parameters see above) has been newly determined from 4541 independent reflexes by the heavy atom method; the positions of all atoms, except the H atoms have been refined to give R = 0.053. The unit cell contains two crystallographically independent molecules. (Mean values of bond lengths and angles see above).     

Die Kristall- und Molekülstruktur des dimeren Dimethylaminodimethylindiums

Crystal and Molecular Structure of Dimeric Dimethylaminodimethylindium Dimeric dimethylamino-dimethylindium was prepared by splitting off methane from the adduct Me₃In? NHMe₂ and characterized by its vibrational spectra. The structure – determined by X-ray analysis – has shown to have the monoclinic space group P2₁/c with a = 7.601, b = 7.336, c = 14.927 Å and β = 119.9°. Patterson, Fourier and Difference synthesis were used for determing the structure, which was refined by least square analysis to an R value of 0.068.     

Zur Reaktivität des Ferriophosphaalkens (Z)‐[Cp*(CO)2FeP=C(tBu)NMe2] gegenüber Propiolsäureestern HC≡C‐CO2R (R=Me,Et) und Acetylendicarbonsäureestern RO2C‐C≡C‐CO2R (R=Me,Et, tBu)

On the Reactivity of the Ferriophosphaalkene (Z)‐[Cp*(CO)₂Fe‐P=C(tBu)NMe₂] towards Propiolates HC≡C‐CO₂R (R=Me, Et) and Acetylene Dicarboxylates RO ₂C‐C≡C‐CO₂R (R=Me, Et, tBu) The reaction of equimolar amounts of (Z)‐[Cp*(CO)₂Fe‐P=C(tBu)NMe₂] 3 and methyl‐ and ethyl‐propiolate ( 2a, b ) or of 3 and dialkyl acetylene dicarboxylates 1a (R=Me), 1b (Et), 1c (tBu) afforded the five‐membered metallaheterocycles [Cp*(CO) =C(tBu)NMe₂] ( 4a, b ) and [Cp*(CO) =C(tBu)NMe₂] ( 5a—c ). The molecular structures of 4b and 5a were elucidated by single crystal X‐ray analyses. Moreover, the reactivity of 4b towards ethereal HBF₄ was investigated.