Addition and ring-opening metathesis polymerizations of new monomers (Me 3 Si-and Me 3 Ge-substituted tricyclononene and tricyclononadienes) were studied. Addition polymerization was carried out on Pd-and Ni-catalyst systems activated by B(C 6 F 5) 3 and/or methylalumoxane. New addition polymers were obtained with good yields up to 70% and with molecular weights (M w) up to 5.6 Â 10 5. Metathesis polymerization was performed using the first-generation Grubbs catalyst. The yields of the first obtained metathesis polymers were higher than 80%, and the M w values were up to 8.8 Â 10 5. It was revealed that the cyclobutene double bond in the studied tricyclononadienes is inactive in both metathesis and addition polymerizations. The relative activities of the substituted tricyclononene-7 and the corresponding tricyclononadiene-3,7 in the metathesis copolymerization were defined using 1 H NMR spectroscopy. It was found that the novel addition polymer poly[(3trimethylgermyl)tricyclononene-7] possesses high gas-transport parameters (for example, P(O 2) ¼ 660 Barrers, P(CO 2) ¼ 3850 Barrers) and solubility-controlled permeation of gaseous hydrocarbons (a (n-C 4 H 10 /CH 4) ¼ 17.3).
Mycobacteria, especially Mycobacterium tuberculosis, are one of the most dangerous types of microorganisms to cause diseases and mortality. Due to the known distinctive structure of their cell wall, mycobacteria are resistant to majority of antibiotics and common chemical disinfectants, including quaternized low molecular weight and polymer biocides. In this work, nonquaternary protonated polydiallylamines (PDAAs) based on protonated monomers of the diallylamine (DAA) series have been synthesized, secondary s-PDAA and tertiary t-Me-PDAA and t-Et-PDAA (with Me and Et N-substituents). The antimicrobial actions of PDAAs on M. tuberculosis and Mycobacterium smegmatis have been studied, namely, dependences of the activity on the amine structure, length of alkyl N-substituents, M w of polymers, treatment time, and cell concentration. All PDAAs examined at different conditions have been found to exhibit strong bactericidal effect on M. smegmatis and M. tuberculosis, including "nonculturable" dormant M. tuberculosis cells. The quaternary counterpart poly(diallyldimethylammonium chloride) (PDADMAC) and current antibiotics rifampicin and ciprofloxacin have been also tested and shown to be significantly less efficient or inactive at all (at the maximum tested concentration of 500 μg mL(-1)). s-PDAA appeared to be the most effective or exhibited similar activity to t-Me-PDAA, while t-Et-PDAA appeared to be less active, especially against M. tuberculosis. The results obtained indicate a key role of the nonquaternary ammonium groups in the mycobactericidal action of PDAAs. Examination under an optical microscope in the epifluorescence mode has evidenced damage of the inner membrane permeability of M. smegmatis cells under the impact of PDAAs after 20 min. Studies on electrophoretic mobility (zeta-potential) of M. smegmatis cells and some model liposomes in the presence of PDAAs have revealed a small negative charge of mycobacteria outer surface and recharge in the presence of PDAAs. A conclusion was made that bactericidal activity of PDAAs is related to the disturbance of the integrity of the mycobacterial cell wall followed by damage of the inner membrane permeability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.