Aggregates matrix isolation

Welker, T., 1978. Optical absorption of matrix isolated silver aggregates and microcrystals, Ber. Bunsenges. Phys. Chem., 82, 40-41. 

Sander W, Gantenberg M (2005) Aggregation of acetic and propionic acid in argon matrices - a matrix isolation and computational study. Spectrochim Acta A 62 902-909... 

Depending on the conditions of preparation, Pd particle diameter is 1-3 nm (-36-960 atoms). This indicates that favorable conditions occur for the simultaneous formation of a great number of nanoparticle nuclei by the chemisorption of reduced ions by protective polymers. Thus, the reduced metal is mainly consumed in forming nuclei, and only a very small part is involved in their growth. The result is the formation of quite small nanoparticles, which is compounded by their high aggregation stability provided by the protective role of the polymer. The so-called theory of matrix isolation was developed to describe nanoparticle formation in polymer solutions, and adequately describes the dependence of their sizes on the reaction conditions and the nature of the stabilizing matrix [72]. 

The role of additionally introduced metal (Mi) is many-sided. On the one hand M] (usually a non-transition metal) may serve as a trap for active centers, binding them more firmly with the support and preventing migration and aggregation. On the other hand these effects can be achieved as a result of the insertion of this metal ion between attached complexes (-M-M -M- type) promoting their matrix isolation. In addition, chemical interactions proceeding on the support (formation of weak M-Mi bonds, co-crystallization, formation of intermetallic compoimds and alloys, etc.) may promote an increase of catalyst productivity. Both types of active center should react with the substrate molecule, so that a complementary mechanism is realized and diffusional limitations are... 

At very low temperature conditions, in matrix isolation, different aggregates of NO and O2 have been characterized by infrared spectroscopy (45). It is not clear whether they are of significance in the thermal autoxidation reaction. Therefore, we also tried to find the signature of the ONOO radical by EPR at lower temperature. We did not resort to matrix isolation, however, because it makes it difficult to set up trapping environments. Frozen gas matrices have sharp melting points, and when the reactants totally immobilized so far suddenly can move almost freely, the reaction will possibly complete too fast for any intermediates to be observed. Therefore, we studied NO oxidation in glassy, viscous hydrocarbons. Some hydrocarbons of low symmetry or hydrocarbon mixtures can be cooled below their... 

Matrix-isolation Shpol skii fluorimetry has been shown to eliminate quantitative artifacts from quenching and aggregation phenomena occurring in Shpol skii low-temperature solid matrices. The linear dynamic range for the fluorescence of PAHs in vapor-deposited alkane matrices smpasses that of solid-state Shpol skii fluorimetry. Thus, the analytical calibration graph for the fluorescence of benzo[ ]ant-hracene in -heptane is linear from 30 pg (the detection limit) to a maximmn amormt of over 35 pg. The... 

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