123525-55-3Relevant academic research and scientific papers
The Syn Conformers of Several 2,11-Dithia(1,4)naphthalenometacyclophanes: Novel Preference for a Conformation with Parallel Benzenoid Rings from Direct Confrontation of Two Different Modes of Non-bonding Interaction
Lai, Yee-Hing
, p. 643 - 648 (2007/10/02)
2,11-Dithia(1,4)naphthalenometacyclophane and its 9-bromo- and 9-fluoro-derivative have been synthesized. 1H and 19F n.m.r. studies have indicated that all three dithiacyclophanes prefer the syn-conformation with near-parallel stacking of aromatic rings.This conformational preference is supported by results from MMP2 calculations.The angle of tilting of the meta-bridged ring is dependent on the 9-substituent.Variable-temperature n.m.r. studies have unexpectedly shown neither a flipping of the meta-bridged ring nor a wobbling of the C-S-C bridges.Possible conformational behaviour is the continuous tilting process of the meta-bridged ring in the rigid syn-conformation.A solvent effect on the chemical shifts of both the reference protons and the fluorine has been observed.
