RESUMEN

A highly efficient chlorobenzene-degrading strain was isolated from the sludge of a sewage treatment plant associated with a pharmaceutical company. The strain exhibited a similarity of over 99.9% with multiple strains of Paenarthrobacter ureafaciens. Therefore, the strain was suggested to be P. ureafaciens LY. This novel strain exhibited a broad spectrum of pollutant degradation capabilities, effectively degrading chlorobenzene and other organic pollutants, such as 1, 2, 4-trichlorobenzene, phenol, and xylene. Moreover, P. ureafaciens LY co-metabolized mixtures of chlorobenzene with 1, 2, 4-trichlorobenzene or phenol. Evaluation of its degradation efficiency showed that it achieved an impressive degradation rate of 94.78% for chlorobenzene within 8 h. The Haldane-Andrews model was used to describe the growth of P. ureafaciens LY under specific pollutants and its concentrations, revealing a maximum specific growth rate (µmax ) of 0.33 h-1 . The isolation and characterization of P. ureafaciens LY, along with its ability to degrade chlorobenzene, provides valuable insights for the development of efficient and eco-friendly approaches to mitigate chlorobenzene contamination. Additionally, investigation of the degradation performance of the strain in the presence of other pollutants offers important information for understanding the complexities of co-metabolism in mixed-pollutant environments.

Asunto(s)

Clorobencenos , Contaminantes Ambientales , Micrococcaceae , Biodegradación Ambiental , Clorobencenos/metabolismo , Fenol , Preparaciones Farmacéuticas

RESUMEN

Copper-catalyzed and organocopper-involved reactions are of great significance in organic synthesis. To have a deep understanding of the reaction mechanisms, the structural characterizations of organocopper intermediates become indispensable. Meanwhile, the structure-function relationship of organocopper compounds could advance the rational design and development of new Cu-based reactions and organocopper reagents. Compared to the mono-carbonic ligand, the C,N- and C,C-bidentate ligands better stabilize unstable organocopper compounds. Bidentate ligands can chelate to the same copper atom via η2-mode, forming a mono-cupra-cyclic compounds with at least one acute C-Cu-C angle. When the bidentate ligands bind to two copper atoms via η1-mode at each coordinating site, the bimetallic macrocyclic compounds will form nearly linear C-Cu-C angles. The anionic coordinating sites of the bidentate ligand can also bridge two metals via µ2-mode, forming organocopper aggregates with Cu-Cu interactions and organocuprates with contact ion pair structures. The reaction chemistry of some selected organocopper compounds is highlighted, showing their unique structure-reactivity relationships.

RESUMEN

A series of unprecedented metallacycles of indium, including indacyclopentadienes (2), spiro indacyclopentadienes (3), aromatic indacyclopentadienyl dianions with an In-Li bond (4), and aromatic indacyclopentadienyl dianions with an In-In bond (5), were synthesized and structurally characterized by single-crystal X-ray structural analysis for the first time. Both indacyclopentadienes 2 and 3 were synthesized by reaction of 1,4-dilithio-1,3-butadienes with InCl3 . Structural transformations between 2 and 3 were observed. Reduction of indacyclopentadienes 2 with an excess amount of lithium afforded aromatic indacyclopentadienyl dianions 4 with an In-Li bond or 5 with an In-In bond, respectively, depending on the substituents on the ring. The aromatic character of 4 and 5 was confirmed by both experimental measurements and theoretical analysis.