This article is cited in
2 papers
Spectroscopy of condensed matter
Spectral properties of an indotricarbocyanine dye upon self-assembly of its $H^{*}$- and $J$-aggregates
N. V. Belkoab,
M. P. Samtsovb,
A. A. Lugovskib a Belarusian State University, Minsk
b A. N. Sevchenko Research Institute of Applied Physical Problems, Belarusian State University, Minsk
Abstract:
Self-assembly of
$H^{*}$- and
$J$-aggregates of an indotricarbocyanine dye in phosphate buffered saline was investigated. At pH value of 7.0 the dye studied was shown to form non-luminescent
$H^{*}$-aggregates with the absorption band peaked at 516 nm, its FWHM being 35 nm (1303 cm
$^{-1}$), whereas,
$J$-aggregates are absent. At pH value of 7.4 the
$H^{*}$-aggregates are not formed, whereas, the
$J$-aggregates are observed. The absorption band of the
$J$-aggregates is peaked at 777 nm, its FWHM being 30 nm (497 cm
$^{-1}$). Photoluminescence quantum yield of the
$J$-aggregates does not exceed 10
$^{-6}$. An increase in the solution temperature from 20 to 31
$^\circ$C results in a 25-fold decrease in the self-assembly time of the
$H^{*}$-aggregates. An increase in the solution temperature from 20 to 80
$^\circ$C is followed by a reversible decay of both the
$H^{*}$- and
$J$-aggregates. The
$H^{*}$-aggregate (
$J$-aggregate) absorption band is reduced two-fold at the solution temperature of 37
$^\circ$C (32
$^\circ$C). Thansitions of the dye aggregates to high-lying electronic excited states were evidenced in the steady-state absorption in the spectral range between 400 and 480 nm.
Keywords:
polymethine dyes, phosphate buffered saline, self-assembly, $H^{*}$-aggregates, $J$-aggregates, electronic spectra. Received: 12.03.2020
Revised: 12.03.2020
Accepted: 29.05.2020
DOI:
10.21883/OS.2020.11.50165.84-20
Fulltext:
PDF file (499 kB)
