4436-96-8Relevant academic research and scientific papers
13C NMR spectroscopic comparison of sterically stabilized meta and para-substituted o-tolyldi(adamant-l-yl)methyl cations with conjugatively stabilized benzyl cations
Lomas, John S.
, p. 2601 - 2609 (2007/10/03)
A series of meta- and para-substituted anti-o-tolyldi(adamant-1-yl)methyl cations has been generated by reaction of anti-o-tolyldi(adamant-1-yl)methanols with trifluoroacetic acid in chloroform. 13C NMR spectroscopy indicates small but significant variations in the chemical shifts of the charged carbon and its nearest neighbours on the adamantyl groups, and departures from additivity of substituent effects on the shifts of the aromatic carbons. Previous work on the closely related di(adamant-1-yl)benzyl cations is discussed. Comparison with data on aryl-substituted carbocations in superacid media reveals marked differences in the aromatic carbon shifts in the two types of carbocation. The dihedral angle between aryl and carbocation planes in aryldi(adamant-1-yl)methyl cations is estimated to be about 60°.
Thermolabile Hydrocarbons, XX. Synthesis, Structure, and Strain of Sym. Tetraalkyl-1,2-diarylethanes
Kratt, Guenter,Beckhaus, Hans-Dieter,Lindner, Hans Joerg,Ruechardt, Christoph
, p. 3235 - 3263 (2007/10/02)
The syntheses of 18 1,1,2,2-tetraalkyl-1,2-diarylethanes 1 - 4 by dimerisation procedures starting with 10 - 13 are reported.In the absence of p-substituents X and with increasing alkyl side chains the α,p-dimers 6 or their aromatic counter parts 7 are obtained besides or instead of 1.The relationships between strain enthalpy Hs, bond lengths, bond angles, torsional angles, and rotational barrier are discussed on the basis of force field calculations.They are supported by two additional experimental structure determinations by X-ray diffraction.
