Biased Bowl-Direction of Monofluorosumanene in the Solid State.

A new curved π-conjugated molecule 1-fluorosumanene ( 1 ) was designed and synthesized that possesses one fluorine atom on the benzylic carbon of sumanene. This compound can exhibit bowl inversion in solution, leading to the formation of two diastereomers, 1 endo and 1 exo , with different dipole moments. Experimental and theoretical investigation revealed an energetical relationship among 1 exo , 1 endo , and solvent to realize the various endo : exo ratios in the single crystals of 1 depending on the crystallization solvent. Significantly, the molecular dynamics (MD) simulations revealed that 1 exo positively worked for the elongation of the stacking structure and the final endo : exo ratio was affected by the relative stability difference between 1 endo and 1 exo derived by solvation. Such an arrangeable endo : exo ratio of 1 realized the preparation of unique materials showing a different dielectric response from the same molecule 1 just by changing the crystallization solvent.