Paraxylylene bisdialkyl sulfonium salts can be polymerized in several different ways, yielding addition polymers as well as condensation polymers. The chemistry leads to a variety of polymers including poly(p‐xylylene), poly(p‐xylylidene), poly(xylylene sulfide)s, poly(xylylene oxide)s, and various α‐substituted polyxylylenes such as poly(p‐xylylene‐α‐dialkylsulfonium chloride). Addition polymers form via xylylene diradical intermediates. Condensation polymerization can be effected either by coupling with aldehydes or by nucleophilic displacement reactions.

Several novel diboronic acid-substituted bipyridinium salts were prepared and, using a fluorescent reporter dye, were tested for their ability to selectively bind various monosaccharides and alpha-hydroxycarboxylates in an aqueous medium. The fluorescence sensing mechanism relies on the formation of a ground-state charge-transfer complex between the dye and bipyridinium. An X-ray crystal structure of this complex is described herein. Glucose selectivity over fructose and galactose was achieved by designing the bipyridinium-based receptors to be capable of attaining a 1:1 receptor/substrate stoichiometry via cooperative diboronic acid binding.

Sweetness and light: A fluorescent thin‐film hydrogel that contains a covalently bound boronic‐acid‐functional quencher (Q) and a fluorescent dye (F; see Figure) continuously senses glucose under physiological conditions through binding of the sugar (S) to a labeled receptor (R).

That's discrimination! An array of boronic acid appended bipyridinium salts (BBVs) as receptor units is able to distinguish twelve saccharides in aqueous solution and at neutral pH values by a fluorescent‐indicator displacement assay. The picture shows the fluorescence increase of a fluorescent dye with BBV receptors after adding saccharides (D‐ribose (Rib), D‐glucose (Glc), D‐fructose (Fru), melibiose (Mel), and lactulose (Lal)).