Two-dimensional
organic–inorganic perovskites have attracted
considerable interest recently. Here, we present a systematic study
of the temperature-dependent photoluminescence on phase pure (n-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–5)
and (iso-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–3) microplates obtained by mechanical exfoliation.
The photoluminescence peak position gradually changes from a red-shift
for n = 1 to a blue-shift for n =
5 with an increase in temperature in the (n-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–5) series,
while only a monotonous blue-shift has been observed for the (iso-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–3)
series, which can be attributed to the competition between the thermal
expansion interaction and electron–phonon interaction. In the
(n-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–5) series, the thermal expansion interaction
and electron–phonon interaction are both gradually enhanced
and the former progressively dominates the latter from n = 1 to n = 5, resulting in the band gap versus
temperature changing from a red-shift to a blue-shift. In contrast,
both of these factors show a weaker layer thickness dependence, leading
to the monotonous blue-shift in the (iso-BA)2(MA)
n−1Pb
n
I3n+1 (n = 1–3) series.
Xin-Sheng-Hua granule, a representative formula for postpartum hemorrhage, has been used clinically to treat postpartum diseases. Its main bioactive components comprise aromatic acids, phthalides, alkaloids, flavonoids, and gingerols among others. To investigate the changes in main bioactive constituents in its seven single herbs before and after compatibility, a rapid, simple, and sensitive method was developed for comparative analysis of 27 main bioactive components by using ultrahigh-performance liquid chromatography with triple quadrupole electrospray tandem mass spectrometry for the first time. The sufficient separation of 27 target constituents was achieved on a Thermo Scientific Hypersil GOLD column (100 mm × 3 mm, 1.9 μm) within 20 min under the optimized chromatographic conditions. Compared with the theoretical content, the observed content of each analyte showed remarkable differences in Xin-Sheng-Hua granule except thymine, p-coumaric acid, senkyunolide I, senkyunolide H, and ligustilide; the total contents of 27 components increased significantly, and the content variation degrees for the different components were gingerols > flavonoids > aromatic acids > alkaloids > phthalides. The results could provide a good reference for the quality control of Xin-Sheng-Hua granule and might be helpful to interpret the drug interactions based on variation of bioactive components in formulae.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.