Organizing co mmittee

The results and conclusions
: the results of the study showed almost complete 
identity of the qualitative composition of the hexane extract of substances obtained by 
extraction and barothermal methods. In the case of ethyl acetate fractions, the difference 
is the presence of chalcones in the substance obtained by the barothermal method. 
Extraction with methylene chloride allows the separation of flavonoids, subsequent 
extraction with ethyl acetate allows the separation of gibberellins. 
Key words
: Populus balsamifera, buds, pinostrobin, extraction, barothermic 
method, flavonoids, chalcones, chromatography, composition of substances. 

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Poster presentation 
66 
INTERACTION OF TETRA-µ-FORMIATO-DIMOLYBDENUM 
MONOHYDRATE WITH A POLYDENTATE DONOR BASE 
 
Akhmedov Eldar Latif, Huseynguliyeva Kenul Fada, Akberova Saida Shamil 
 
Azerbaijan Medical University, Department of Pharmaceutical Toxicology and 
Chemistry, Baku 
 
Previously, we found that the tetra-µ-carboxylate complex of dimolybdenum, in 
particular, Mo
2
(O
2
CH)
4
H
2
O, is capable of forming complexes of the Mo
2
(O
2
CH)
4
L
2
type (L are organic bases). Introduction of donor bases into axial positions leads, in 
comparison with the initial complex, to more noticeable changes in the values of 
ν(MoMo), ν
s
(MoO), ν
as
(COO), and ν
s
(COO) in the spectra of Mo
2
(O
2
CH)
4
L
2
-type 
complexes. In continuation of the research, it is advisable to obtain complexes of the 
Mo
2
(O
2
CH)
4
L
2
type, where L is 4-aminopyridine (4-NH
2
Py). When carrying out the 
reaction of Mo
2
(O
2
CH)
4
H
2
O with the indicated donor base, the task was also to study 
the preferred methods for coordinating axial ligands. 
In the case of 4-NH
2
Py, two modes of coordination are possible: through the nitrogen 
atom of the amino group Mo-N (amine), or through the nitrogen atom of the heterocycle 
Mo-N (pyridine).
In the IR spectra of Mo
2
(O
2
CH)
4
(4-NH
2
Py)
2
there are intense absorption bands with 
maxima near 3475 and 3375, 3230 cm
-1
. We assigned them to asymmetric and 
symmetric stretching vibrations of the amino group of 4-aminopyridine. The 
corresponding frequencies are increased compared to ν(NH
2
) of uncoordinated 4-
aminopyridine by 31-60 cm
-1
, i.e. in the 4-NH
2
Py molecule, the donor nitrogen atom of 
the NH
2
groups does not participate in the bond with the molybdenum atom, since 
otherwise, the frequencies of stretching vibrations ν(NH
2
) of the amino group would 
have to decrease significantly. The absorption band of the bending scissor vibrations of 
the amino group in the region of 1655 cm
–1
practically does not shift. 
Thus, 4-aminopyridine forms a bond with molybdenum in Mo
2
(O
2
CH)
4
(4-NH
2
Py)
2
through the nitrogen atom of the pyridine ring, which is consistent with an increase in 
the frequencies of the stretching vibrations of the ring in the region of 1500-1600 and 
1000-1100 cm
-1
by 10-30 cm
-1
. These data are consistent with the stoichiometric rules, 
according to which the closure of the metallocycle through the functional groups of 
cyclic ligands located in the β-position relative to each other is very difficult, and in the 
γ-position it is almost impossible. 
Thus, the study of the spectral characteristics of the Mo
2
(O
2
CH)
4
(4-NH
2
Py)
2
complexes showed that the nitrogen atom of the heterocycle has more efficient donor 
properties than the nitrogen atom of the amino group located in the para position to the 
nitrogen atom of the heterocycle. 
In the region 400-500 cm
-1
in the IR spectrum of Mo
2
(O
2
CH)
4
(4-NH
2
Py)
2
three 
intense absorption bands were found with maxima at about 435, 440 and 464 cm
-1
; the 
first two absorption bands, which are inactive in the Raman spectra, are also present in 
the spectrum of the initial complex, Mo
2
(O
2
CH)
4
H
2
O, which gives reason to attribute 
them to asymmetric stretching vibrations of the Mo–O bonds. 

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Poster presentation 
67