The First Triple-Decker Complex with a Carbenium Center, [CpCo(μ-C3B2Me5)RuC5Me4CH2]+: Synthesis, Reactivity, X-Ray Structure, and Bonding

The first derivative of the methylium cation with the triple-decker substituent, [CpCo(C3B2Me5)RuC5Me4CH2]PF6 ( 2 PF6), was synthesized from the reaction of the triple-decker complex CpCo(C3B2Me5)RuCp* ( 1 ) with the salt of the trityl cation [CPh3]+. The X-ray crystal structure of 2 PF6 reveals that the methylium carbon is bound to the ruthenium with Ru−C bond length of 2.259 Å and corresponds to the description of its structure as η6-fulvene-ruthenium. Reactions of 2 PF6 with nucleophiles OH−, Ph3P, Et3N led to the corresponding derivatives of 1 in high yields. Aromatic amines PhNEt2 and 4-MeC6H4NH2 react with 2 PF6 to give the electrophilic aromatic substitution products quantitatively. Chemical reduction of 2 PF6 with Zn powder in tetrahydrofuran leads to the formation of the bis(triple-decker) derivative (CpCo(C3B2Me5)RuC5Me4CH2)2 ( 10 ) with a CH2CH2-bridge. The structures of complexes 4 , 7 – 10 were determined by X-ray diffraction. Density functional calculations support the crystallographically determined geometry of 2 and allow rationalization of some characteristics of its structure, spectroscopy, and reactivity

Full-scale bioreactor pretreatment of highly toxic wastewater from styrene and propylene oxide production

The wastewater originating from simultaneous production of styrene and propylene oxide (SPO) is classified as highly polluted with chemical oxygen demand level in the range 5965 to 9137mgL-1-as well as highly toxic. The dilution factor providing for a 10 percent toxic effect of wastewater samples in a test with Paramecium caudatum was 8.0-9.5. Biological approach for pretreatment and detoxification of the wastewater under full-scale bioreactor conditions was investigated. The number of suspended microorganisms and the clean up efficiency were increased up to 5.5-6.58×108CFUmL-1 and 88 percent, respectively during the bioreactor's operation. Isolates in the Citrobacter, Burkholderia, Pseudomonas, and Paracoccus genera were dominant in the mature suspended, as well as the immobilized microbial community of the bioreactor. The most dominant representatives were tested for their ability to biodegrade the major components of the SPO wastewater and evidence of their role in the treatment process was demonstrated. The investigated pretreatment process allowed the wastewater to be detoxified for conventional treatment with activated sludge and was closely related to the maturation of the bioreactor's microbial community. © 2014 Elsevier Inc

Composition of the oil-slime microbial community as determined by analysis of the 16S rRNA gene

Analysis of the 16S rRNA genes of the cultured microorganisms of industrial oil-slime revealed predominance (~85-90%) of the Gammaproteobacteria in the community of aerobic heterotrophs and specific oil-slime degraders. Relation of the isolated strains with members of the genera Pseudomonas, Stenotrophomonas, and Enterobacter was established. Analysis of the same gene in the total DNA from the oil-slime revealed greater microbial diversity (~20 operative taxonomic units determined by T-RFLP) than in the cultured part of the community, which included ∼12 different colony types. Three major restriction fragments were found, with their total area ∼50%. These results demonstrated the low morphological and phylogenetic diversity of the oil-slime bacterial community. © 2013 Pleiades Publishing, Ltd