Polymorphism and Crystal Morphology of Poly(ethylene oxide)−2-Methyl Resorcinol Supramolecular Complexes

Monomeric and Dimeric Carboxylic Acid in Crystalline Cavities and Channels of Delta and Epsilon Forms of Syndiotactic Polystyrene

Delta (δ) and epsilon (ε) co-crystalline forms of syndiotactic polystyrene with a carboxylic acid guest were obtained by sorption of liquid hexanoic acid in syndiotactic polystyrene films exhibiting delta and epsilon nanoporous-crystalline forms. The characterization study is facilitated by axially stretched syndiotactic polystyrene films, used both for polarized FTIR spectra and for WAXD fiber patterns. Particularly informative are two carbonyl-stretching FTIR peaks, attributed to monomeric and dimeric hexanoic acid. The dichroism of these carbonyl peaks indicates that both delta and epsilon phases are able to include hexanoic acid as isolated guest molecules, while only the epsilon phase is also able to include dimeric hexanoic acid molecules in its crystalline channels. The inclusion of both isolated and dimeric hexanoic acid species in the epsilon form crystalline channels produces extremely fast hexanoic acid uptakes by syndiotactic polystyrene epsilon form films.

A novel ammonium pentaborate – poly(ethylene-glycol) templated polymer-inclusion compound

Reaction of ammonia borane with poly-ethylene glycol at slightly elevated temperatures leads to the formation of the first known example of a borate-based polymer inclusion compound with a pentaborate framework structure.

Crystalline structure of an ammonia borane–polyethylene oxide cocrystal: a material investigated for its hydrogen storage potential

Rare polymer crystal structure formed by ammonia borane in polyethylene oxide exhibiting a snake-like chain through the crystal.

Enantiomeric guests with the same signs of chiral optical responses

The chiral response of non-racemic molecules, being guests of s-PS co-crystalline films, does not depend on their R or S molecular chirality but essentially only on the polymer host supramolecular chirality.