Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 11, pp. 1663−1669.
Pleiades Publishing, Ltd., 2013.
Original English Text © Yu.G. Vlasov, A.A. Kruchinin, D.S. Ryabukhin, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 11, pp. 1711−1717.
OF SYSTEMS AND PROCESSES
Fluorescence Quenching Features in Non-Conjugated
Yu. G. Vlasov, A. A. Kruchinin, and D. S. Ryabukhin
St. Petersburg State University, St. Petersburg, Russia
Received November 15, 2013
Abstract—It was found that, in diacetylene oligomers constisred of monomer units with an non-conjugated system
of π-electrons, the efﬁ ciency of ﬂ uorescence quenching depends on the chain length within the range from 2 to 40
repeating units. This effect is consistent with the model of propagation of delocalized excitons in a noncovalent
aggregate of several oligomer chains. The result obtained in the study conﬁ rms the assumption that a collective
effect due to excitons can exist in a supramolecular aggregate of non-conjugated molecules.
In recent years, considerable attention was paid
to syntheses and studies of organic semiconductors
because they are considered aspromising materials
for ﬁ eld-effect transistors , light-emitting diodes
, chemical sensors , and solar cells . Most of
materials of this kind are polymers with conjugated
aromatic rrings and multiple bonds, which have a
delocalized system of π-electrons. The delocalization of
electrons is due to the migration of excitons , which
is of particular interest for chemical sensors and solar
cells. In a polymeric sensor material, the diffusion of
long-lived excitons along the polymer chain provides a
multifold ampliﬁ cation of the analytical signal, which
is a desirable positive effect . By contrast, a long
exciton lifetime is undesirable in solar cells because of
reducing the charge separation efﬁ ciency .
Thus, it is of interest to reveal factors affecting the
lifetime and diffusion length of excitons in organic
One of factors of this kind is the conjugation length
of the system of π-electrons. This length is reduced by
introduction into a repeating unit a hexane ring , an
ether linkage [7, 8] or CH
group . Polymer materials
with broken conjugation of π-electrons are of interest
because they can be implemented as self-organizing
aggregates in which repeating units are linked to each
other by a noncovalent interaction . Materials of this
kind are are known as supramolecular. They can ﬁ nd
use in optoelectronic devices, and, therefore, are studied
now together with the classical polymers in which
repeating units are linked by covalent bonds .
At present, supramolecular materials are constructed
on the basis of conjugated molecules. This approach
looks like generally accepted rather than based on
fundamental limitations of physicochemical nature.
An interesting task in this situation is to study the
ﬂ uorescence quenching, which depends on the
exciton migration, in organic polymers with btoken
intramolecular conjugation and aggregation capability.
To solve this problem, we used in the present study
oligomers based on diacetylene compounds, with a
chain length of 2 to 40 repeating units.
Synthesis of diacetylene oligomers. The compounds
under study were synthesized by the Glaser’s reaction
 by polycondensation of DEP monomer (see scheme,
c). Divalent copper was used as a catalyst , which
simpliﬁ es the reaction as compared with its conventional
version . The general formula of the synthesized