Vk. Aggarwal et al., DIMETHYLSULFONIUM FLUOREN-9-IDE - SOLUTION STRUCTURE AND DYNAMIC BEHAVIOR OF A SEMI-STABILIZED SULFONIUM YLIDE, Journal of the Chemical Society. Perkin transactions. I, (19), 1997, pp. 2811-2813
The semi-stabilised ylide, dimethylsulfonium fluoren-9-ide, has been s
tudied by variable temperature NMR and found to adopt a conformation i
n which the filled orbital on carbon is perpendicular to the lone pair
on sulfur. The rotational barrier (Delta G(double dagger)) around the
ylide C-S bond is found to be 42.0 +/- 1.0 kJ mol(-1).