The First Crystal Structure Analysis of Cyclododeca-2,8-diyne-1,10-diols
摘要:
Cyclododeca-2,8-diyne-1,10-diol, (6), C12H16O2, and 1,10-dimethylcyclododeca-2,8-diyne-1,10-diol, (11), C14H20O2, have been prepared and their structures determined. Both crystallize in centrosymmetric space groups and the molecules have approximate C-2 symmetry. For compound (6), the lengths of the triple bonds are 1.184(3) (C2=C3) and 1.189(3) Angstrom (C8=C9). The bond angles at the triple bonds (C1-C2=C3 and C8=C9-C-10) deviate by less than 6 degrees from 180 degrees. For compound (11), the lengths of the triple bonds are 1.190(3) (C2=C3) and 1.188(3) Angstrom (C8=C9), and the bond angles at the triple bonds are close to 175.5 degrees. In both compounds, the two 3-hexyne chains maintain a 'crossed' arrangement whereas the two alkylene chains are arranged in a manner similar to that described for unsubstituted cyclododecane.
The title compound, C26H48O2Si2, has been prepared and its structure determined. The bond angles at the triple bond are close to 174.5 degrees (average) and the length of the triple bond is 1.179(3)Angstrom. The alkylene chains maintain a screw-type arrangement similar to that found in unsubstituted cyclododecane.