Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II)
The hydrophobic reagent 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR) was investigated as part of a cloud-point extraction (CPE) system for the spectrophotometric determination of Zn(II). In the system, complexes with different stoichiometries, including 1:1 and 2:2 (Zn:HTAR), are formed. Their ground...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-09-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/29/18/4511 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850260126920867840 |
|---|---|
| author | Kiril B. Gavazov Petya V. Racheva Antoaneta D. Saravanska Fatma Genc Vassil B. Delchev |
| author_facet | Kiril B. Gavazov Petya V. Racheva Antoaneta D. Saravanska Fatma Genc Vassil B. Delchev |
| author_sort | Kiril B. Gavazov |
| collection | DOAJ |
| description | The hydrophobic reagent 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR) was investigated as part of a cloud-point extraction (CPE) system for the spectrophotometric determination of Zn(II). In the system, complexes with different stoichiometries, including 1:1 and 2:2 (Zn:HTAR), are formed. Their ground-state equilibrium geometries were optimized at the B3LYP/6-31G level of theory. The obtained structures were then used to calculate vertical excitation energies in order to generate theoretical UV/Vis absorption spectra. The comparison between theoretical and experimental spectra demonstrated that, under optimal conditions, a binuclear complex containing oxygen-bridging atoms is the dominant species. The absorbance was found to be linearly dependent on the concentration of Zn(II) within the range of 15.7 to 209 ng mL<sup>−1</sup> (<i>R</i><sup>2</sup> = 0.9996). The fraction extracted (%<i>E</i>), logarithm of the conditional extraction constant (log <i>K</i><sub>ex</sub>), and molar absorption coefficient (<i>ε</i>) at <i>λ</i><sub>max</sub> = 553 nm were calculated to be 98.3%, 15.9, and 4.47 × 10<sup>5</sup> L mol<sup>−1</sup> cm<sup>−1</sup>, respectively. The method developed is characterized by simplicity, convenience, profitability, sensitivity, and ecological friendliness. It has been successfully applied to the analysis of pharmaceutical and industrial samples. |
| format | Article |
| id | doaj-art-a5b01eb2e1424479affaec9ce2a64b0f |
| institution | OA Journals |
| issn | 1420-3049 |
| language | English |
| publishDate | 2024-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj-art-a5b01eb2e1424479affaec9ce2a64b0f2025-08-20T01:55:42ZengMDPI AGMolecules1420-30492024-09-012918451110.3390/molecules29184511Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II)Kiril B. Gavazov0Petya V. Racheva1Antoaneta D. Saravanska2Fatma Genc3Vassil B. Delchev4Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaDepartment of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaDepartment of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, BulgariaFaculty of Pharmacy, Istanbul Yeni Yüzyıl Üniversitesi, 26 Yılanlı Ayazma Caddesi, 34010 Istanbul, TurkeyFaculty of Chemistry, University of Plovdiv ‘Paisii Hilendarskii’, 24 Tsar Assen St., 4000 Plovdiv, BulgariaThe hydrophobic reagent 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR) was investigated as part of a cloud-point extraction (CPE) system for the spectrophotometric determination of Zn(II). In the system, complexes with different stoichiometries, including 1:1 and 2:2 (Zn:HTAR), are formed. Their ground-state equilibrium geometries were optimized at the B3LYP/6-31G level of theory. The obtained structures were then used to calculate vertical excitation energies in order to generate theoretical UV/Vis absorption spectra. The comparison between theoretical and experimental spectra demonstrated that, under optimal conditions, a binuclear complex containing oxygen-bridging atoms is the dominant species. The absorbance was found to be linearly dependent on the concentration of Zn(II) within the range of 15.7 to 209 ng mL<sup>−1</sup> (<i>R</i><sup>2</sup> = 0.9996). The fraction extracted (%<i>E</i>), logarithm of the conditional extraction constant (log <i>K</i><sub>ex</sub>), and molar absorption coefficient (<i>ε</i>) at <i>λ</i><sub>max</sub> = 553 nm were calculated to be 98.3%, 15.9, and 4.47 × 10<sup>5</sup> L mol<sup>−1</sup> cm<sup>−1</sup>, respectively. The method developed is characterized by simplicity, convenience, profitability, sensitivity, and ecological friendliness. It has been successfully applied to the analysis of pharmaceutical and industrial samples.https://www.mdpi.com/1420-3049/29/18/4511zinc(II)centrifuge-less cloud-point extraction6-Hexyl-4-(2-thiazolylazo)resorcinolspectrophotometric determinationTD DFTbinuclear complex |
| spellingShingle | Kiril B. Gavazov Petya V. Racheva Antoaneta D. Saravanska Fatma Genc Vassil B. Delchev Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) Molecules zinc(II) centrifuge-less cloud-point extraction 6-Hexyl-4-(2-thiazolylazo)resorcinol spectrophotometric determination TD DFT binuclear complex |
| title | Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) |
| title_full | Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) |
| title_fullStr | Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) |
| title_full_unstemmed | Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) |
| title_short | Mono- and Binuclear Complexes in a Centrifuge-Less Cloud-Point Extraction System for the Spectrophotometric Determination of Zinc(II) |
| title_sort | mono and binuclear complexes in a centrifuge less cloud point extraction system for the spectrophotometric determination of zinc ii |
| topic | zinc(II) centrifuge-less cloud-point extraction 6-Hexyl-4-(2-thiazolylazo)resorcinol spectrophotometric determination TD DFT binuclear complex |
| url | https://www.mdpi.com/1420-3049/29/18/4511 |
| work_keys_str_mv | AT kirilbgavazov monoandbinuclearcomplexesinacentrifugelesscloudpointextractionsystemforthespectrophotometricdeterminationofzincii AT petyavracheva monoandbinuclearcomplexesinacentrifugelesscloudpointextractionsystemforthespectrophotometricdeterminationofzincii AT antoanetadsaravanska monoandbinuclearcomplexesinacentrifugelesscloudpointextractionsystemforthespectrophotometricdeterminationofzincii AT fatmagenc monoandbinuclearcomplexesinacentrifugelesscloudpointextractionsystemforthespectrophotometricdeterminationofzincii AT vassilbdelchev monoandbinuclearcomplexesinacentrifugelesscloudpointextractionsystemforthespectrophotometricdeterminationofzincii |