Environmental context Total organofluorine and known fluorosurfactants were quantified in 11 aqueous film forming foams (AFFFs) used to extinguish fires in Ontario, Canada, and one commercial AFFF product. By comparing the concentrations of known fluorosurfactants with the total organofluorine, less than 10% of the fluorosurfactants were identified in half of the samples. Our biodegradation experiment with one of the fluorosurfactants using waste-water treatment plant sludge showed that it was a potential source of perfluoroalkyl carboxylates, which are persistent in the environment. Abstract Eleven aqueous film forming foam (AFFF) samples that were used to extinguish fires in Ontario, Canada, and one commercial product, were analysed using a variety of analytical techniques to obtain structural information and quantities of organofluorine and known perfluoroalkyl and polyfluoroalkyl substances (PFASs). The NMR spectra of the foams distinguished the fluorosurfactants that were synthesised by either electrochemical fluorination or telomerisation. Total organofluorine content was quantified using total organofluorine–combustion ion chromatography (TOF-CIC), which revealed that the samples contained from 475 to 18 000µgFmL–1. The common AFFF component 6 : 2 fluorotelomermercaptoalkylamido sulfonate (FTSAS) was quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS) together with perfluoroalkane sulfonates (PFSAs), perfluoroalkyl carboxylates (PFCAs) and fluorotelomer sulfonates (FTSAs); in five samples, 6 : 2 FTSAS was present in concentrations greater than 1000µgmL–1. By comparing the concentrations of these quantifiable fluorochemicals with the total organofluorine content, it was evident that in half of the AFFF samples, less than 10% of the fluorochemicals were identified; in two of the samples, perfluorooctane sulfonate (PFOS) accounted for ~50% of the total organofluorine content. Our degradation experiment with 6 : 2 FTSAS using waste-water treatment plant sludge showed that 6 : 2 FTSAS was a potential source of FTSAs, fluorotelomer alcohols and PFCAs in the environment.

The incorporation of multiple p-carborane cages within an aliphatic polyester dendrimer was accomplished through the preparation of a bifunctional carborane synthon. A p-carborane derivative having an acid and a protected alcohol functionality was found to efficiently couple to peripheral hydroxyl groups of low-generation dendrimers under standard esterification conditions. Deprotection of carborane hydroxyl groups allowed for further dendronization through a divergent approach using the highly reactive anhydride of benzylidene-protected 2,2-bis(hydroxymethyl)propanoic acid. This approach was used to prepare fourth- and fifth-generation dendrimers that contain 4, 8, and 16 carborane cages within their interior. Upon peripheral deprotection to liberate a polyhydroxylated dendrimer exterior, these structures exhibited aqueous solubility as long as a minimum of eight hydroxyl groups per carborane were present. Several of the water-soluble structures were found to exhibit a lower critical solution temperature. Additionally, irradiation of these materials with thermal neutrons resulted in emission of gamma radiation that is indicative of boron neutron capture events occurring within the carborane-containing dendrimers.

The modification of para‐carborane with appropriate functionalities for incorporation within a dendrimer framework was accomplished by functionalizing the carbon centers with protected alcohol and free acid groups. These compounds are excellent candidates for utilization as functional linkers between two generations of an aliphatic polyester dendrimer structure. Future assembly of these structures will result in dendritic macromolecules containing carboranes within their interior and will be enveloped by hydrophilic groups (hydroxyls) to maintain their water solubility and biocompatibility. These structures have potential applications in Boron Neutron Capture Therapy and Synovectomy. Additionally, carboranes were coupled to polymerizable acrylate structures, and it was shown that the resulting carborane monomers could be polymerized using living free‐radical polymerization techniques.