The course “MOLECULAR PHOTONICS”
15 lectures (2 academic hours each one)
1.
Introduction.
Two photonics: the photonics-science and the photonics-technology. The subject and tasks of
the molecular photonics.
The review of photophysics bases.
Molecules in the ground and excited states. Electronic excitation. Stark-Einstein law. FrankCondon rule. Internal conversion. Kasha rule. The ways of the electronic excitation.
The relaxed and not-relaxed ground and excited states. The structural and solvate relaxation.
2.
The singlet and triple states. The spin-orbit interaction. The intercombination conversion. El
Sayed rule. The influence of heavy atoms.
The “death” of the excited state of molecules. Radiationless processes. Vibrational relaxation.
Radiative pathways of the excited state deactivation. Fluorescence and phosphorescence. The
energy gap law.
3.
The general scheme of the transformation of molecular states: Jabłonski diagram.
Quantitative characteristics of the luminescence.
Fluorescent Stokes shift. Rate constants for radiation and radiationless processes. Quantum
yields of fluorescence and phosphorescence. Vavilov law. “True” and radiation lifetimes of
molecules in the excited state.
4.
Luminescence classification according to an excitation method.
Photoluminescence, chemiluminescence, bioluminescence, electroluminescence,
triboluminescence. Other luminescence species.
Photoluminescence.
Steady-state and pulse fluorimetry. The main principles of functioning of photometric and
luminometric equipment. Measuring fluorescence and phosphorescence spectra. Measuring
fluorescence quantum yields. Measuring of excited state lifetime.
5.
Chemiluminescence.
Reaction mechanisms resulting in the formation of excited molecules. Quantum yield and
other quantitative parameters of the chemiluminescence. Some wide-spread
chemiluminophores. Using the chemiluminescence in the biochemistry and the medicine.
6.
The interaction of excited molecules with the medium.
Solvatochromy and solvatofluorochromy. Lippert and Bakhshiyev equations. The estimation
of dipole moment changing upon the exitation of molecules. The design and the philosophy of
the creation of fluorescent probes for medium polarity examinations and for special
biophysical investigations.
7.
Energy transfer between excited and not-excited molecules.
Radiative and radiationless energy transfer. Förster resonance energy transfer (FRET). The use
of radiationless energy transfer for biophysical and biochemical investigations, FRET and
BRET technics. Physical photosensitization.
8.
The review of the photochemistry.
The photochemistry laws. Elementary acts of photochemical reactions – dissociation, electron
transfer, proton transfer. Diabatic and adiabatic processes. Chemical photosensitization. Twoquantum photoreactions.
The main types of photochemical reactions – photodissociation, photosynthese,
photoreduction, photooxydation, photosubstitution, photoisomerization. Examples of these
reactions.
9.
Quantitative characteristics of photoreactions.
Quantum yield of a photochemical process from singlet and triplet states. The experimental
determination of the photoreaction quantum yield. Rate constants of photochemical reactions.
The technics of photochemical experiment. Photochemical equipment.
10. Acid-base properties of molecules in the excited states.
Photoacids and photobases. Förster method for the estimation of photodissociation constants.
Ion pairs in the excited states.
Phototautomerization: inter- and intramolecular proton transfer in the excited states (ESIPT).
Ratiometric fluorescent probes.
11. The behaviour of coordination compounds upon excitation.
Ionofluorophores. The structure and the principles of design of ionofluorophore indicators.
The competition between the complex formation and the proton and charge transfer.
12. Complex formation in the excited state. Exciplexes. Donor-acceptor and “exciton” bonds
between molecules. The dimerization in the excited state. Excimers. Using eximer and
exciplex fluorescence in biophysical experiments.
13. Photochromism.
Physical and chemical photochromisms. Photochrome systems based on cis/transisomerisation, tautomerization, cyclization/decyclization, rearrangements. Examples of
photochrome transformations. The use of the photochromism in technics. The photochromism
in biological systems.
14-15. Workshops.
The workshops will be based on student’s reports and on discussions concerning these
reports.
Doctorants will choose themes connecting with the photonics course and with their own work.
This should help to initiate the use of the obtained information in practical domains interesting
for students.
First workshop will be held in midterm of the Photonics course depending on themes chosen
by students. In case of need, the number of workshops may be increased.