
%0 Journal Article
%A Cosmo, R 
%A Sternhell, S 
%T Steric Effects. Inversion of 4,5-Disubstituted 9,10-Dihydrophenanthrenes
%J Australian Journal of Chemistry
%D 0987/01/01
%V 40
%N 1
%P 35-47
%K 
%R https://doi.org/10.1071/CH9870035
%U https://www.publish.csiro.au/paper/CH9870035 
%X Six 4,5-di-X-9,l0-dihydrophenanthrenes (X = H, F, OCH3, Cl, CH3, CF3) were synthesized and their inversion rates were investigated by n.m.r., spectroscopy. The barriers to inversion at a standard temperature (&#8710;G&#8225;;340) ranged from <25 to >120 kJ mol-l and showed good correlation with the van der Waals radii of the interacting substituents at C4 and C5 and with the previously proposed 'apparent overlap' parameter. 
