Mechanochemically induced methods are commonly used for the depolymerization of polymers, including plastic and agricultural wastes. So far, these methods have rarely been used for polymer synthesis. Compared to conventional polymerization in solutions, mechanochemical polymerization offers numerous advantages such as less or no solvent consumption, the accessibility of novel structures, the inclusion of co-polymers and post-modified polymers, and, most importantly, the avoidance of problems posed by low monomer/oligomer solubility and fast precipitation during polymerization. Consequently, the development of new functional polymers and materials, including those based on mechanochemically synthesized polymers, has drawn much interest, particularly from the perspective of green chemistry. In this review, we tried to highlight the most representative examples of transition-metal (TM)-free and TM-catalyzed mechanosynthesis of some functional polymers, such as semiconductive polymers, porous polymeric materials, sensory materials, materials for photovoltaics, etc.

Polyvinyl chloride (PVC) plays an important role in industry; however, due to its uncontrolled accumulation in the environment, the methods for its utilization are of high demand. Herein we wish to report an approach for the utilization of PVC via its use as a carrier for some azole-based drugs, such as 2-mercaptobenzothiazole (multi-activity drug), 4-oxo-1,4-dihydropyrazolo[5,1-c]-1,2,4-triazine-3,8-dicarboxylic acid diethyl ester (antidiabetic drug) and 5-methyl-6-nitro-7-oxo-1,2,4-triazolo[1,5-a]pyrimidinide (antiviral drug). The abovementioned approach involves the reaction between PVC and potassium or sodium salts of these azole-based drugs either in solution or under ball-milling conditions. The as-obtained PVCs modified with azole-based drugs were isolated for the first time and characterized by means of 1H NMR-spectroscopy as well as gel-permeation chromatography (GPC).

1,4-Bis(5-phenyl-2-oxazolyl)benzene (POPOP) is a common scintillation fluorescent laser dye. In this manuscript, the synthesis of 2-Ar-5-(4-(4-Ar’-1H-1,2,3-triazol-1-yl)phenyl)-1,3,4-oxadiazoles (Ar, Ar’ = Ph, naphtalenyl-2, pyrenyl-1, triphenilenyl-2), as PAH-based aza-analogues of POPOP, by means of Cu-catalyzed click reaction between 2-(4-azidophenyl)-5-Ar-1,3,4-oxadiazole and terminal ethynyl-substituted PAHs is reported. An investigation of the photophysical properties of the obtained products was carried out, and their sensory response to nitroanalytes was evaluated. In the case of pyrenyl-1-substituted aza-POPOP, dramatic fluorescence quenching by nitroanalytes was observed.

Iptycenes are common building blocks for the small-molecules or polymer-based chemosensors and fluorophores. In addition, iptycene derivatives are widely presented in polymers of intrinsic microporosity (PIMs) as materials for the separation and purification technologies. In this manuscript we wish to report a mechanochemical approach to pentiptycene-based polyesters and polycarbonates as, possibly, new representatives of PIMs. Our approach involves the polycondensation reaction between 5,7,12,14-tetrahydro-5,14:7,12-bis([1,2]benzeno)pentacene-6,13-diol (pentiptycene-6,13-diol) and triphosgene or oxalyl chloride under ball-milling conditions. The obtained polymers were characterized by means of 1H NMR- and IR-spectroscopy. As the last step, the fluorescence “turn-off” response of pentiptycene-6,13-diol and two pentiptycene-based polymers towards nitroanalytes (2,4-dinitrotioluene (DNT) and 2,4,6-trinitrophenole (picric acid, PA)) was investigated, and Stern-Volmer constants as high as 1o4 M–1 were observed.

The research into quorum sensing inhibitors is mainly directed towards fighting pathogenic bacteria resistant to therapy with antimicrobial drugs. Natural quorum sensing inhibitors may serve as an effective alternative to antibiotics, since they are less likely to cause the development of drug resistance of pathogenic microbiota. Currently, the search for effective inhibitor molecules and analysis of structure–activity relationships among natural compounds is considered to be the most obvious strategy towards solution of the antibiotic resistance problem. Since plants have co-evolved with the microbial environment and have been constantly exposed to bacterial infections, they successfully developed chemical mechanisms to fight external pathogens, in particular the quorum sensing inhibition. The review considers the secondary metabolites of various classes of plants such as terpenes, quinones, coumarins, stilbenes, alkaloids, curcuminoids, flavonoids, phenolic compounds, and their derivatives and analogues that possess quorum quenching activity. Some aspects of the structure–activity relationships for the described compounds are highlighted for the first time. The bibliography includes 139 references.