RESUMO
As chemists and materials scientists, it is our duty to synthesize and utilize materials for a multitude of applications that promote the development of society and the well-being of its citizens. Since the inception of metal-organic frameworks (MOFs), researchers have proposed a variety of design strategies to rationally synthesize new MOF materials, studied their porosity and gas sorption performances, and integrated MOFs onto supports and into devices. Efforts have explored the relevance of MOFs for applications including, but not limited to, heterogeneous catalysis, guest delivery, water capture, destruction of nerve agents, gas storage, and separation. Recently, several start-up companies have undertaken MOF commercialization within industrial sectors. Herein, we provide a brief overview of the state of the MOF field from their design and synthesis to their potential applications, and finally, to their commercialization.
RESUMO
In search of fluorinated functional groups which could undergo defluorination, and therefore be included in novel non-polluting fluorinated surfactants, omega-(bis(trifluoromethyl)amino)alkane-1-sulfonates (BTFMA-AS) with a homologue distribution from seven to thirteen methylene groups were synthesized and investigated for aerobic biodegradation applying both a standardized test and a fixed-bed bioreactor (FBBR). These compounds were prepared as part of a screening study for potentially mineralizable fluorinated endgroups.Application of hybrid triple quadrupole-linear ion trap mass spectrometry (QqQ(LIT)-MS) coupled to high-performance liquid chromatography (HPLC) allowed the tracking of primary degradation as well as the detection and structural elucidation of biotransformation intermediates. An understanding of the fragmentation pathway of the test compounds allowed selective precursor ion scans to reveal the presence of stable fluorinated metabolites. Structures were confirmed by enhanced product ion scans and MS(3) scans in the linear ion trap mode.The primary biodegradation rate and the extent of biodegradation were found to be chain-length dependent, with higher homologues being completely primarily degraded within 10 days. For the first time, two simultaneous metabolic pathways for substituted linear alkane-1-sulfonates were discovered: Desulfonation, oxidation to a carboxylic acid and subsequent chain-length shortening by beta-oxidation dominated the metabolism. This pathway resulted in the formation of 3-(bis(trifluoromethyl)amino)propionic acid and bis(trifluoromethyl)aminoacetic acid, which showed recalcitrance in this experiment. Oxidation of the alkyl chain to the respective carbonyl derivative represents the minor pathway. Only the long-chain homologues of these oxidized species were partially degraded; the short-chain homologues were not attacked.
Assuntos
Alcanossulfonatos/metabolismo , Espectrometria de Massas em Tandem/métodos , Biotransformação , Cromatografia Líquida de Alta Pressão/métodos , OxirreduçãoRESUMO
As a new potentially mineralizable fluorinated surfactant, 9-[4-(trifluoromethyl)phenoxy]nonane-1-sulfonate was synthesized and exposed to a standardized Zahn-Wellens test (OECD 302B). After the release of fluoride indicating the mineralization of the trifluoromethyl group, 9-[4-(trifluoromethyl)phenoxy]nonane-1-sulfonate was subjected to a further biodegradation test carried out in a fixed bed bioreactor (FBBR). Evolution of biodegradation routes and pursuit was done by quadrupole linear ion trap mass spectrometer (QqLIT-MS) and quadrupole time-of-flight tandem mass spectrometer (QqTOF-MS). Biotransformation was initiated via hydroxylation in the alkyl chain at different positions. Hydroxy-9-[4-(trifluoromethyl)phenoxy]nonane-1-sulfonate was further oxidized with subsequent scission of the molecule forming mainly p-(trifluoromethyl)phenolate, which was mineralized releasing inorganic fluoride. These results demonstrate, that the new synthesized fluorosurfactant 9-[4-(trifluoromethyl)phenoxy]nonane-1-sulfonate is completely biotransformed. However, some intermediates, depending on the position of hydroxylation, impede further mineralization.