Coordinative interaction between nitrogen oxides and iron-molybdenum POM MoFe.

The process of adsorption of nitrogen monoxide and dioxide by the giant Keplerate nanocluster Mo72Fe30 was studied in detail under ambient conditions and air/argon atmosphere. The obtained Raman and IR spectra showed that the coordination of NOx to the Mo72Fe30 leads to the formation of nitrate ions by sharing the bridged or terminal oxygen in FeO6 polyhedra with the adsorbed NO2 molecules. In accordance with elemental analysis and X-ray photoelectron spectroscopy, the composition of the produced complex was found to be [POM-(NO2)x]·(NO2)y (where x = 6, y = 14 ± 3).

Comparison of optoacoustic and photothermal-lens determination of lipopolysaccharides.

As a primary aim, several approaches to photothermal (thermal-lens) and optoacoustic determination of exogenous pyrogens (lipopolysaccharides) based on photometric procedures for their determination at the microgram level and below are compared. The limits of detection of lipopolysaccharides by thermal-lens spectrometry and optoacoustic spectroscopy are at a level of 2-100 ng/mL, and the conditions of optoacoustic and photothermal procedures are the same. Optoacoustic spectroscopy is advantageous in determining suspensions, while thermal lensing is superior in determining lipopolysaccharides from homogenous aqueous solutions.