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Issue 20, 2017
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Threshold concentration in the nonlinear absorbance law

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A new nonlinear relationship of the absorption coefficient with the concentration was proposed, allowing the calculation of the threshold concentration, which shows that there is a deviation from the Beer–Lambert law. The nonlinear model was successfully tested on a stable dimeric phthalocyanine ligand of J-type in solvents with different polarity. It was shown that deviation from the linearity is connected with a specific association of the macrocyclic molecules, which, in the case of non-polar solvents, leads to the formation of H-aggregates composed of J-type dimeric molecules. The aggregation number was estimated to be less than 1.5, which has allowed us to conduct a series of analytical experiments in a wide range of concentrations (1 × 10−6–5 × 10−4 mol L−1).

Graphical abstract: Threshold concentration in the nonlinear absorbance law

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The article was received on 09 Mar 2017, accepted on 10 Apr 2017 and first published on 12 Apr 2017

Article type: Paper
DOI: 10.1039/C7CP01514C
Citation: Phys. Chem. Chem. Phys., 2017,19, 12953-12958
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    Threshold concentration in the nonlinear absorbance law

    A. Yu. Tolbin, V. E. Pushkarev, L. G. Tomilova and N. S. Zefirov, Phys. Chem. Chem. Phys., 2017, 19, 12953
    DOI: 10.1039/C7CP01514C

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