1070-4272/02/7509-1501$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 9, 2002, pp. 1501!1505. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 9,
2002, pp. 1533!1537.
Original Russian Text Copyright + 2002 by Bobashova, Dudkina, Nikolaeva.
AND POLYMERIC MATERIALS
Formation of Hydrogen Bonds in the System
A. S. Bobashova, M. M. Dudkina, and M. N. Nikolaeva
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received May 13, 2002
Abstract-The interaction of poly-1,10-decamethyleneacetamidine with some low-molecular-weight additives
was studied. It was shown by nuclear magnetic relaxation and IR spectroscopy that linear dyes of the bis-
hydroxyalkanone type form hydrogen bonds with amidine groups of the polymer, and the strength of these
bonds depends on the degree of dissociation of the dye.
Amidines are widely used in medicine and tech-
nology; also, they are the subjects of active research
in organometallic chemistry. At present, low-molecu-
lar-weight amidines are well known, while polymers
containing amidine groups, which are of interest for
many applications, are not adequately studied . The
structure and characteristics of these polymers were
C NMR both in solids and
in solutions, and also by thermal gravimetric analysis
. Polyamidines have the general formula 3NH3
CR=N3, where R is an aliphatic or aromatic group.
It is known  that polymeric networks of poly-
amidines, formed by hydrogen bonds with dyes, are
capable of nonlinear optical (NLO) behavior. As
regards production of complexes with NLO behavior,
polyamidines show much promise, which is due to
high basicity of amidine groups . In this work, we
studied the structure of complexes of ionogenic comb-
shaped polymers, namely, poly-1,10-decamethylene-
acetamidine, with the functional group in the main
chain and low-molecular-weight polyconjugated NLO
dyes of the bis-hydroxyalkanone type. It was shown
previously  that poly-1,10-decamethyleneacetam-
idine can form fairly heat-resistant, stable for a long
time (more than 1 year) film-forming polymeric com-
plexes with dyes, capable of efficient generation of the
third harmonic. However, the relationship between the
chemical structures formed by polyamidine with NLO
dyes and macroscopic characteristics of the resulting
associates has not been adequately studied .
Here we paid attention to variation of the character-
istics of the polymers as a result of formation of
comb-shaped structures and their possible supra-
molecular ordering. It was important to study the
mechanism of formation of supramolecular polymer
structure upon addition of the dye and the mechanism
of rupture of the existing hydrogen-bonded polymer
network. In addition, it is believed that the relation-
ship between the acidity of the low-molecular-weight
compound and the basicity of the polyamidine should
significantly affect the structure of the complexes.
To confirm this assumption, the compounds having
similar structure but different dissociation constants
were selected as low-molecular-weight additives.
The aim of this work was also to determine the tem-
perature range of existence of hydrogen bonds in the
system polyamidine3low-molecular-weight additive
and to elucidate changes in the supramolecular struc-
tures with time.
Formation of hydrogen bonds in the above systems
was studied by NMR relaxation and IR spectroscopy.
IR spectroscopy is widely used for analysis of systems
forming hydrogen bonds . NMR relaxation allows
monitoring of the mobility of polymer chains and
determination of structural changes of molten systems
In this work we studied the interaction of poly-
1,10-decamethyleneacetamidine (hereinafter, poly-
[3(CH ) 3NH3C
[3(CH ) 3NH3C
with the following additives: 4,4`-dihydroxydiphenyl