Vortex-Induced Harmonic Light Scattering of Porphyrin J-Aggregates

2021 ◽  
Author(s):  
Shingo Hattori ◽  
Michèle Moris ◽  
Kazuteru Shinozaki ◽  
Kazuyuki Ishii ◽  
Thierry Verbiest
Keyword(s):  
Light Scattering ◽  
J Aggregates

Quantitative investigations of the aggregation behaviour of hydrophobic anilino squaraine dyes through UV/vis spectroscopy and dynamic light scattering

1999 ◽  
Vol 77 (5-6) ◽  
pp. 903-912 ◽  
Author(s):  
James Wojtyk ◽  
Andrew McKerrow ◽  
Peter Kazmaier ◽  
Erwin Buncel
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Particle Diameter ◽  
Water Medium ◽  
Thermodynamic Control ◽  
Squaraine Dyes ◽  
Water Solvent ◽  
Aggregation Behaviour ◽  
Vis Spectroscopy ◽  
J Aggregates

In continuing studies of the aggregation behaviour of squaraine dyes in DMSO-water mixtures, we have examined a series of symmetrical anilino-based squaraines with increasing N-alkyl chain length (n-butyl, n-octyl, and n-dodecyl). The aggregation behaviour was assessed through UV/vis spectroscopic and Dynamic Light Scattering (DLS) studies with quantitative interpretation based on exciton theory. This class of N-alkyl squaraines forms two distinct solution aggregates, Type J and Type H, depending on the composition of the DMSO-water medium. DLS measurement of the aggregates in the Type J and Type H morphologies showed that (i) the particle diameter increased with increasing hydrophobicity; (ii) DMSO has a large effect on the aggregate size; (iii) Type J aggregates are of equal dimensions with Type H aggregates. Moreover, even though as the DMSO-water solvent composition is varied the UV/vis spectra of Type H and Type J aggregates remained unchanged, the number of molecules comprising each aggregate varies widely. It is proposed that the dynamic conversion (J →> H) results from intramolecular reorganization of individual molecules within the aggregate. Quantification of aggregation through DLS has further developed the "kinetic" versus "thermodynamic" control model of dye aggregation.Key words: squaraine, dynamic light scattering, DMSO-water mixtures, self-assembly, kinetic/thermodynamic control.

Collision induced hyper-Rayleigh light scattering in CCl4

1996 ◽  
Vol 88 (3) ◽  
pp. 683-691 ◽  
Author(s):  
P. KAATZ ◽  
D.P. SHELTON
Keyword(s):  
Light Scattering ◽  
Rayleigh Light Scattering ◽  
Rayleigh Light
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