Self-organized J aggregates of pseudoisocyanine dye in nanometer dimensions at the vicinity of a glass/solution interface: a time-resolved and total-internal-reflection fluorescence spectroscopic study

Aggregation and Decomposition of a Pseudoisocyanine Dye in Dispersions of Layered Silicates

“…The main kind of J-aggregates (λ MAX = 558 nm) forms with reaction time. The presence of the two kinds of J-aggregates is not a new finding and has been reported elsewhere (21,48,49). The metastable nature of J-aggregates, absorbing light at higher wavelengths, has already been observed (49).…”

“…Heating a solution decreases both H-and J-aggregation in favor of monomers (17). Enhancement of PIC aggregation was observed with the adsorption of PIC cations in various reaction systems, including solutions of polyelectrolytes (18,19) on the surface of silica (20), glass (21), and in sol-gel systems (22) as well as in various kinds of molecular films, mainly of the Langmuir-Blodgett type (23,24). Aggregation of PIC cations depends on both the composition of the PIC solution and the properties of the substrate (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26).…”

Spectral properties and structure of the J-aggregates of pseudoisocyanine dye in layered silicate films

“…Indeed, the PIC/FH film absorbs light with a tail to relatively low wavelengths (<570 nm) (Fig. 2), which is typical for the J -aggregates formed in hydrophilic environments [43] (Table 2).…”

“…Two types of the J -aggregates have been observed for other systems [43,44] and are characterized in detail in the paper, dealing with the PIC aggregation at an aqueous/borosilicate interface [45]: J -aggregates absorbing light at lower wavelengths (maximal absorption at 570 nm) were formed in the bulk solution phase; species absorbing at 579 nm interacted directly with the glass surface [45]. J -aggregates absorbing at 578 nm were observed in hydrophobic Langmuir-Blodgett films [46].…”

“…One of the main properties of the J -aggregates is the absorption spectrum: Light absorption by chromophores, which form J -aggregates, is characterized by a sharp spectral band of relatively high molar absorption coefficients and at significantly lower energies than the absorption associated with the transitions of individual (nonaggregated) dye cations [1,9]. Other properties include those having been observed for J -aggregates in general, such as fluorescence [10], spectral-hole burning phenomena [11], nonlinear optical properties [12,13] and energy transfer [14,15].…”