ChemInform Abstract: Structure and Dynamics of Crowns Containing the Phenyldinaphthylmethane Subunit (a Three-Bladed Propeller): Observations of Correlated Rotation of the Propeller Blades and Certain Ether Segments.
Abstract
Following a previously published method the crowns (I) are prepared from the respective benzylidene-bis(2-naphthol) in THF, NaH, and the appropriate α,ω-bis(tosyloxy)-polyoxaalkane in THF (20 h reflux; no yields given).
ChemInform Abstract
Following a previously published method the crowns (I) are prepared from the respective benzylidene-bis(2-naphthol) in THF, NaH, and the appropriate α,ω-bis(tosyloxy)-polyoxaalkane in THF (20 h reflux; no yields given). The torsional propeller movement is fluxional at room temp. on the NMR time scale for some crowns, with ΔG of ca. 10-11 kcal/mol, while for others (regarded as locked propellers at room temp.), ΔG is ca. 19 kcal/mol. X-ray crystal structures of (Ia) ( P21/n with Z=4) and of the KSCN salt of (Ib) (P21/c with Z=4) are described.
