Thiacalixarenes are synthetized using phenol derivatives and sulfur. The chemical reaction ranks under electrophilic aromatic substitutions followed by an elimination of water and then a second aromatic substitution. The reaction is base catalysed. Calixarenes are difficult to separate because it is all too easy to end up with complex mixtures of linear and cyclic oligomers with different numbers of repeating units. With finely tuned starting materials and reaction conditions synthesis can also be surprisingly easy.
Thiacalixarenes, like calixarene are characterised by a three-dimensional basket (vase or chalice shape). In thiacalixarene derivatives, the internal volume is around 10 cubic nanometers. Thiacalixarenes are characterised by a wide upper rim and a narrow lower rim. With phenol as a starting material, the 4 hydroxyl groups are intrannular on the lower rim. The basket form (cone conformation) is stabilized by hydrogen bonding between the four hydroxyl group. In case of substituted hydroxyl group, other conformers can be observed, like 1,2 or 1,3 alternate.
US Patent Issued to Konica Minolta Business Technologies on April 30 for "Toner and Toner Manufacturing Method" (Japanese Inventors)
Apr 30, 2013; ALEXANDRIA, Va., April 30 -- United States Patent no. 8,431,298, issued on April 30, was assigned to Konica Minolta Business...