312
Volume 5, Issue 10: Special Issue
(EJAR)
ISSN: 2181-2020
MPHAPP
THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL
CONFERENCE
“
MODERN PHARMACEUTICS: ACTUAL
PROBLEMS AND PROSPECTS
”
TASHKENT, OCTOBER 17, 2025
in-academy.uz
SPECTROSCOPIC ANALYSIS OF 2-METHYLTHIOBENZOXAZOLE AND THEIR
COMPLEX COMPOUNDS WITH 3D-METALS
Sadullaeva S.A.
National University of Uzbekistan, Tashkent city, Republic of Uzbekistan
e-mail: ashurovabbos4@gmail.com
https://doi.org/10.5281/zenodo.17335409
Relevance of the research:
derivatives of benzoxazole, which is a heterocyclic compound
containing nitrogen and oxygen, are used in research as a starting material for the synthesis of many
bioactive structures, and many scientific studies have been conducted on their structure and
properties.
Derivatives of oxazole and 2-aminothiobenzoxazole are recognized as substances of medical
importance. It is known that oxazole derivatives are substances with various pharmacological effects.
For example, it is used as a remedy against cancer, microbes, inflammation, herbicide, antibacterial,
antiviral, antihistamine, antioxidant, estrogen receptor inhibitor, and hepatitis C virus. Compounds of
2-aminothiobenzoxazole also have luminescent properties.
Purpose of the study:
Synthesis of new complex compounds based on the ligand of
benzoxazole derivatives of Co (II) and Cu (II) salts and study of their composition, structure and
properties, as well as determination of the regularities of complex formation.
Methods and techniques of the topic:
Based on the results of IR spectroscopy of metal
complexes obtained on the basis of 2-aminotiobenzoxazole derivatives of Co (II) and Cu (II) salts,
the results of IR spectroscopy were studied.
Result:
Comparing the IR spectra of L and its complexes with cobalt and copper nitrate salts, it
can be said that the position of symmetrical valence vibrations of the C=N bond and asymmetrical
valence vibrations of -C-N= in the spectra, during the transition from the ligand to the complexes, a
heterocyclic bond is formed, shifted by 12-26 cm-1 for the first to the low-frequency region, and by
3-10 cm-1 for the second (Table 1). The regions of asymmetric valence vibrations of the C=N bond
shift to low frequencies by 12-26 cm-1. This change can be explained by the shift in electron density
during complex formation at one of the nitrogen atoms of the oxazole ring. The position of the valence
vibration region of the S-CH3 bond, located in the region of 1031 cm-1, remains unchanged. Due to
the presence of a small amount of moisture in the ligand molecule, the valence vibrations also
occurred in the region of 3080-3271 cm-1, which remained unchanged in the complex, but in the IR
spectrum of the complexes, these lines are more resolved and it has maxima at 3095 and 3271 cm-1.
Table 1
In the IR spectra of ligands (L) and complexes based on them, the main oscillation
frequencies (cm-1)
Birikma
(-
CH3)
(=C-
H)
(CH
3
-S-
)
(-C-N-
)
(-C=N-
)
(-C-O-
)
M-N
L
1628
1418
1031
3271
684
1519
-
[CoL
2
(NO
3
)
2
]
1621
1496
1094
3362
680
1556
419
[CuL
2
(NO
3
)
2
]
1624
1476
1044
3193
696
1551
419
Summary:
In the IR spectra of the complexes, the lines appearing at 481-459 cm-1 are
associated with the valence vibrations of the N-M bond. Consequently, we can conclude that the
coordination of heterocyclic ligands occurs at the expense of endocyclic nitrogen atoms. In the
spectrum of the analyzed complex, an intense band of symmetrical valence vibrations of the NO3-
313
Volume 5, Issue 10: Special Issue
(EJAR)
ISSN: 2181-2020
MPHAPP
THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL
CONFERENCE
“
MODERN PHARMACEUTICS: ACTUAL
PROBLEMS AND PROSPECTS
”
TASHKENT, OCTOBER 17, 2025
in-academy.uz
group appeared at 1375 cm-1. This indicates that the nitrate group is monodentately attached to the
central atom via oxygen. Thus, according to the IR spectroscopy of Co (II) complexes, the nitrate ion
is monodentately coordinated with the central atom as an acidoligand. The conclusions obtained from
the IR spectrum data are consistent with the results of X-ray.
