THESIS
2021
1 online resource (xxi, 158 pages) : illustrations (some color)
Abstract
Photoluminescence, including fluorescence and phosphorescence, contributed
significantly to our modern life. The photo-physics of photoluminescent materials in various
medium and phases, especially in different solvents, extraordinarily attracted particular interests.
From the antique origin of organic photoluminescent materials, every massive progress in such
fields, such as excited-state intramolecular proton transfer, regular and twisted intramolecular
charge transfer, were under the influences of solvent effect. Solvatochromism, which was termed
to represent all the above situations, play an essential role for decades and get familiar to almost
all researchers.
However, when more specific phenomena were revealed as more materials were
discovered, the word “solvatochromism” is not co...[
Read more ]
Photoluminescence, including fluorescence and phosphorescence, contributed
significantly to our modern life. The photo-physics of photoluminescent materials in various
medium and phases, especially in different solvents, extraordinarily attracted particular interests.
From the antique origin of organic photoluminescent materials, every massive progress in such
fields, such as excited-state intramolecular proton transfer, regular and twisted intramolecular
charge transfer, were under the influences of solvent effect. Solvatochromism, which was termed
to represent all the above situations, play an essential role for decades and get familiar to almost
all researchers.
However, when more specific phenomena were revealed as more materials were
discovered, the word “solvatochromism” is not comprehensive enough to conclude all photophysics
of fluorescence compounds encountering different medium and in different phases. So,
we need to beyond “solvatochromism” and revisit the whole area of research.
There are two aspects to extend the concept of “solvatochromism”. The first one is to
beyond the word “chromism”. Colour is not the only thing that changed when the solvent
changed. By precise design of donor-acceptor systems, we could tune the energy gap between
two excited singlet states and yield a slow internal conversion rate, which leads the system to
anti-Kasha’s rule behaviour. Such behaviour could be accurately triggered in high polarity
solvents and switched off in low-polar environments. The system was used as a bio-imaging
agent with the polarity-mapping ability and applied into cell classification with the assistance of
convolutional neural networks.
Another aspect is beyond the word “solvato”. The solvent is expected but not the only
thing that would change the fluorescence molecules' quantum environment. Solubility change
aggregates formation and crystallization would also tremendously affect the optical properties.
Besides above all, we also revisited calculation methods applied in mentioned projects
and rebuild a self-consistent calculation infrastructure, including a benchmark of different
approaches and a simple machine learning algorithm for prediction, for specific research about
extended “solvatochromism”.
Post a Comment