Thiacrown compounds with 1,2-dicyano-1, 2-dithioethene units

Abstract

S2On+1-Coronands containing one 1,2-dicyano-1,2-dithioethene unit ((Z)-2(n=1), 3(n=2), 4(n=3)) and macrocyclic tetrathioethers containing two 1,2-dicyano-1,2-dithioethene units bridged by propylene(6), butylene(8), pentylene(9) or hexylene(10) were synthesized by the reaction of (Z)-disodium-1,2-dicyanoethene-1,2-dithiolate with oligoethylene glycol dichlorides and ω,ω’-dibromoalkanes, respectively. The (E)-isomer of macrocycle 2 is the first example of an S/O-coronand with planar chirality. The enantiomers were separated by capillary gas chromatography with modified P-cyclodextrin as stationary phase. Unsaturated dithia[12]crown-4 (Z)-2 is a selective extracting agent for PdCl2. In the solid state the unsaturated tetrathia[14]crown-4 6 and tetrathia[16]crown-4 8 adopt “chair-like” conformations. Each of four sulfur atoms of both macrocyclic tetrathiaethers direct one lone electron pair toward the hole of the macrocycle. © 1993 IUPAC