Bildung und Kristallstruktur eines dimeren sauerstoffverbrückten Titanaminobisphenoxides

Formation and Crystal Structure of an Oxygen Bridged Titanium Amino Bisphenoxide Di‐(μ‐oxo)‐titan‐bis[aminobisphenoxide] ( 3 ) was obtained by reaction of (i‐Prop)₂TiL* ( 2 ) {L* = O‐4, 6‐(t‐Bu)₂C₆H₂‐2‐CH₂‐[1, 4‐N₂C₅H₁₀]‐2'‐CH₂‐4', 6'‐(t‐Bu)₂C₆H₂O] with water in a molar ratio 1:1 in diethylether. Both i‐Propyl moieties are substituted yielding the dimeric oxygen bridged amino bisphenoxide complex. The six coordinate Ti atoms are a result of Ti—N and Ti—O interactions of the corresponding atoms of the amino bisphenoxide ligand and the bridging O atoms. The central planar Ti₂O₂ ring may be considered as the general structural feature of the title compound: Space group P1¯, Z = 1, lattice dimensions at —60°C: a = 11.6899(4), b = 11.7873(4), c = 12.6462(4) Å, α = 98.070(1), β = 99.660(1), γ = 95.343(1)°, R₁ = 0.0469, wR₂ = 0.1049, GooF = 0.939.     

Bildung eines hochexplosiven Valenzisomeren des Indens aus Dilithiopentalen und Chlorcarben

Formation of a Highly Explosive Valence Isomer of Indene from Dilithiopentalene and Chlorocarbene The principal product of the reaction of dilithiopentalene ( 3 ) with methyllithium and methylene chloride is shown by difference-FT-NMR, spectroscopy to be tetracyclo[4.3.0.0^3,5.0^4,6]nona-1,7-diene ( 8 ). This laterally bridged benzvalene derivative explodes violently at temperatures as low as ?40° when concentrated. Controlled rearrangement in diluted solution gives indene ( 4 ). The key step in the formation of the tetracyclic C₉H₈-compound 8 is suggested to be an intramolecular 1,4-carbene addition.     

Photochemische reaktionen—XXXIII: Molekular- und kristallstruktur eines photoprodukts aus gibberelun C

In connection with studies concerning the photochemistry of carbonyl gibberellins, the structure of a ring D seco photoproduct 1 obtained upon UV irradiation of gibberellin C has been established by X-ray analysis and the molecular packing determined. The lattice parameters are a=b=11.935 Å and c=31.717 Å; the space group is P4₃2₁2. The final discrepancy factor R was 0.063.     

Die Bildung eines Chloroformhydrates

Ohne Zusammenfassung     

Silylen-Reaktionen mit Selenophen und einem Tellurophen: Bildung und Strukturen eines 1,3-Diselena-2,4-disiletans und eines 1,3-Ditellura-2,4-disiletans [1]

Silylene Reactions with Selenophene and a Tellurophene: Formation and Structures of a 1,3-Diselena-2,4-disiletane and a 1,3-Ditellura-2,4-disiletane [1] Di-tert-butylsilylene, generated by photolysis of hexa-tert-butylcyclotrisilane, reacts with selenophene or 2,5-dimethyltellurophene by chalcogen abstraction to furnish the 1,3-diselena-2,4-disiletane 6 and 1,3-ditellura-2,4-disiletane 7 ring systems. The X-ray structure analyses of 6 and 7 reveal strictly planar four-membered rings with the smaller endocyclic angles at the chalcogen and the larger angles at the silicon atoms.