Kristallstruktur eines überbrückten 1,2,3-Oxadiazolidin-5-ons

The Crystal Structure of a Bridged 1,2,3-Oxadiazolidin-5-one Derivative 3-(2-Allylphenyl)-4-phenylsydnone ( 1 ) undergoes in solution an intramolecular, 1,3-dipolar cycloaddition reaction to give 2-oxo-1-phenyl-1,5-methano-1,2,4,5,6,11-hexahydro [1,2,3] oxadiazolo [3,2-a] cinnoline ( 2 ). The unique 1,2,3-oxadiazolidin-5-one structure of this molecule has been proved by X-ray analysis. The crystal structure has been solved by direct methods and refined by full-matrix least squares calculations to R = 0,046. The crystal system is orthorhombic, space group P_bca, with unit cell dimensions a = 10,546, b = 15,482, c = 16,531 Å.     

Darstellung,Eigenschaften und Molekülstruktur eines Titan-tris(diazadien)-Komplexes

Preparation, Properties, and Molecular Structure of a Titanium-tris(diazadiene) Complex (R = i-C₃H₇) 1 was obtained by reaction of TiCl₄ · 2 THF with Li₂(NR? CH = CH? NR) in the presence of the ligand molecules. The compound was characterized by ¹H-, ¹³C-n.m.r., and mass spectroscopy. The molecular structure was determined by X-ray diffraction. The bonding distances in the identically coordinated diazadiene ligands are similar to those of radical.     

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.