A Clathrate Form of Syndiotactic Poly(p-methylstyrene) Containing Two Different Types of Cavities

Abstract

The crystal structure of the clathrate form of syndiotactic poly(p-methylstyrene) containing benzyl chloride is presented. This structure presents a monoclinic unit cell (cell constants a ) 26.2 Å, b ) 11.8 Å, c ) 7.9 Å and γ ) 116°) in which the s(2/1)2 polymer helices and guest molecules are packed according the space group P2 1 /a. This molecular complex represents, to our knowledge, the first case of polymeric clathrate form in which in the same crystal are present two kinds of cavities having different shape and dimensions: R class cavities (containing two guest molecules) and class cavities (containing one guest molecule). The contemporaneous presence of these two types of cavities is originated by a disorder in the arrangement of right-and lefthanded helices in the crystals related to the particular staggered layout of the layers of chains containing the cavities in which helices of a given chirality can be randomly substituted by enantiomorphous ones.

Understanding at molecular level of nanoporous and co-crystalline materials based on syndiotactic polystyrene

“…Relevant new co-crystalline and nanoporous materials are expected in the future also for other stereoregular polymers that are able to form co-crystalline phases, like e.g. syndiotactic poly-p-methyl-styrene [110][111][112][113], syndiotactic poly-p-chloro-styrene [114], syndiotactic polymethyl-methacrylate [115], or polyethylene-oxide [116,117].…”

Advanced materials based on polymer cocrystalline forms

“…Polymeric cocrystalline forms are quite common for several regular and stereoregular polymers, such as, for example, isotactic21–23 and syndiotactic polystyrene (s‐PS),24–40 syndiotactic poly‐ p ‐methyl‐styrene,41–47 syndiotactic poly‐ m ‐methyl‐styrene,48, 49 syndiotactic poly‐ p ‐chloro‐styrene,50 syndiotactic poly‐ p ‐fluoro‐styrene,51 polyethyleneoxide,52–55 poly(muconic acid),56, 57 polyoxacyclobutane,58 poly(vinylidene fluoride),59, 60 syndiotactic polymethylmethacrylate,61–63 isotactic poly‐4‐methyl‐1‐pentene,64 or poly(2,6‐dimethyl‐1,4‐phenylene ether) (PPO) 65–68…”

Absorption Kinetics of Phenol into Different Size Nanopores Present in Syndiotactic Polystyrene and Poly (p-methylstyrene)

“…This is because the pore size of sPPMS is larger than that of sPS because of the methyl group attached to phenyl ring in sPPMS. According to Tarallo et al, [32] the clathrate forms ofand -classes contain two and one guest molecules in the pore, respectively. They reported that nanoporous sPPMS cast-crystallized from o-xylene forms a -class clathrate.…”

“…The and class clathrates have a ttgg conformation with a period of 7.8 ± 0.1 Å. [29][30][31][32]The t6g2t2g2 conformation class clathrate has a period of 11.7 ± 0.1 Å. [33] A porous crystalline structure can be constructed in a crystal with the ttgg conformation by removing the solvent.…”