1,4-Addition versus 1,2-addition of free germylenes Me2Ge to 1,3-dienes

New cycloadditions of free Me₂Ge to 13 different 1,3-dienes are reported: 1,4-addition is favoured for electron deficient dienes, high s-cis content, and C-1 - C-4 distances around 3.10Å. Factors disfavouring it promote formation of 3,4-disubstituted 1-germacyclopentanes via postulated 1,2-addition, and insertion of a second diene.     

The geometry and vibrational frequencies of formyl cyanide,CHOCN

The structure of the recently prepared formyl cyanide molecule has been determined by ab initio calculations up to the level of split valence plus polarization with inclusion of electron correlation (6-31G¹MP3). The 6-31G¹MP3 geometry is: r_e(CN) = 1.160, r_e(C-C) = 1.476, r_e(CO) = 1.207, r_e(CH) = 1.098 Å, α_e(C-CN) = 178.32°, α_e(CCO) = 121.63°, and α_e(HCO) =     

Analyse vibrationnelle infrarouge et Raman du benzosélénophène et du benzotellurophène

Infrared (4000-200 cm⁻¹; vapour solid and solution dissolved in inert and proton acceptor solvents) Raman (4000-100 cm⁻¹, solid and solution) spectra of benzoselenophene and benzotellurophene have been recorded. A complete attribution of the fundamental vibrations is proposed. The fundamental vibration wavenumbers evolution for a series of monoheteroatomic benzoheterocycles C₈H₆X with X = O, S, Se and Te is analysed.     

Recent advances in 1D nanostructured catalysts for photothermal and photocatalytic reduction of CO2

The development of photocatalysts that can efficiently convert CO₂ into other valuable chemicals via photocatalytic and photothermal processes is critical to the current energy and climate change problems. However, low separation of charge carriers, short light absorption, and low activation of CO₂ molecules in photocatalysis limit the catalysts’ performance. Designing 1D heterostructures containing multiple materials can be a viable solution as their unique properties, such as high surface area, short diffusion paths of charge carriers, and enhanced light absorption properties, can potentially promote the reaction rate and product selectivity. In this review, we summarize the general features of heterostructures involving nanotubes, nanowires, nanorods, and nanobelts. Next, the main synthesis strategies are briefly highlighted, followed by the most important findings concerning their catalytic activity in the photothermal and photocatalytic CO₂ reduction processes. The article concludes with some of the current challenges and potential solutions.     

Photosensitizer conjugate-functionalized poly(hexamethylene guanidine) for potentiated broad-spectrum bacterial inhibition and enhanced biocompatibility

Pathogen infection is the main cause of human morbidity and death. Traditional antibiotics usually sterilize bacteria in chemical ways, which tends to develop serious antibiotic resistance. Cationic polymers exhibit good bacterial inhibition with less resistance, but often face severe cytotoxicity toward normal cells. The optimization of polymeric antimicrobials for enhanced bactericidal capacity and improved biocompatibility is quite meaningful. In addition, photodynamic therapy (PDT) is a therapeutic modality with less susceptibility to develop resistance. Herein, a typical commercial polymeric antimicrobial, polyhexamethylene guanidine (PHMG) was selected for current proof-of-concept optimization due to its excellent bactericidal capacity but moderate biocompatibility. Eosin-Y (EoS) was copolymerized to afford EoS-labeled polymer conjugates, poly(2-(dimethylamino) ethyl methacrylate-co-eosin), P(DMAEMA-co-EoS), which was conjugated with PHMG to afford a novel polymeric antimicrobial, P(DMAEMA-co-EoS)-b-PHMG-b-P(DMAEMA-co-EoS), noted as PEoS-PHMG. It could efficiently kill broad-spectrum bacteria by physical damage and photodynamic therapy. Compared with PHMG, the bacterial inhibition of PEoS-PHMG was potentiated after the functionalization. Furthermore, PEoS-PHMG exhibited low cytotoxicity and minimal hemolysis, which was demonstrated by cell viability assays toward LO2 cells and RAW 264.7 cells as well as hemolytic assays against red blood cells. These results confirmed that the resultant PEoS-PHMG could act as promising alternative antibacterial materials with excellent broad-spectrum bacterial inhibition and favorable biocompatibility.     

Enhancement of filtration efficiency by electrical charges on nebulized particles

There have been few investigations of effects of electrical charge, carried by lab-generated particles, on filtration efficiency testing. Here, we measured the elementary charge on particles and the fraction of particles carrying that charge with a combined electrometer, differential mobility analyzer, and scanning mobility particle sizer. A typical solid NaCl aerosol and liquid diethylhexyl sebacate (DEHS) aerosol were generated with Collison and Laskin nebulizers, respectively. Our experimental results showed that NaCl aerosols carried more charge after aerosol generation. The average net elementary charge per particle was approximately 0.07. The NaCl aerosol was overall positively charged but contained a mixture of neutral and charged particles. Individual particles could carry at most four elementary charges. According to constant theorem, we speculated that original NaCl aerosol contained 17% neutral, 45% positive-, and 38% negative-charged particles in the diameter range from 30 to 300 nm. A Kr-85 neutralizer was used to decrease the charge on the NaCl particles. Our results indicated that the DEHS aerosol was electrically neutral. The effects of electric charge on particle collection by electret and electroneutral high efficiency particulate air (HEPA) filters were analyzed. Theoretical calculations suggested that charges on original NaCl aerosol particles enhanced the filtration efficiency of HEPA filters.     

Polymer nanoparticles of N-vinylpyrrolidone loaded with an organic aminonitroxyl platinum (iv) complex. Characterization and investigation of their in vitro cytotoxicity

Russian Chemical Bulletin - The conditions for obtaining stable aqueous solutions of a lipophilic aminonitroxyl platinum complex, namely, e-amine-d-(4-amino-2,2,6,6-tetramethylpiperidine 1-oxyl)-a,...     

Correlation effects in a reaction-diffusion system with nonlinear damping

The Schlögl model of a chemical reaction is generalized to take into account the correlation effects arising from the finiteness of the correlation time. This generalization is based on a generalization of Fisher’s equation with a memory function and cubic nonlinearity. Oscillatory states are demonstrated to be possible in such a system. The dissipative structure existence conditions are specified.