The vibrations of ʋ (M-N)7-bromo8HQ and ʋ(M-O) may be attributed to certain new bands in the ranges of (414-432) and (570-590) cm-1 and cm-1, respectively . Figures 2-6 show the results; FTIR spectra data of the bands of ligand (HAS) and their complexes were found in Table 4.
The results obtained from the FTIR spectra are further supported by the 1H-NMR analyses. It is accomplished by comparing the changes in the 1HNMR spectra of generated complexes to those of free ligands. Table 5 shows the data for the shifting (𝛿) in ppm for several kinds of protons in the ligand (HAS) and its complexes for Pt(II) and Pd(II), while the 1HNMR spectra were obtained in DMSO-d6 solution (Figures 7-9).
The free ligand (HAS) shows the signal at (11.65), (2.52) ppm, and the varied signals observed in the range (7.11-8.06) ppm for NHsulfa, CH3oxazole, and Ar-Hbenzene respectively . The free ligand (HAS) displays signals at (9.33)ppm and multiplet signals in the range (8.09-9.03)ppm for OH-quinoline and H-quinoline respectively . All signals of the spectra of complexes of Pd (II) and Pt (II) were a light shift that refers to non-sharing of these groups in metal ions coordination while OH-quinoline signal in the ligand(HAS) is disappeared in the spectra of its complexes indicate sharing oxygen atom with metal ions in the coordination after losing proton .
Electronic-spectrum and magnetic properties
The geometry of solid complexes can be determined by looking at their electronic spectra. As a result, electronic spectrum features were concentrated on the discrepancies between the molecule's ground and excited states . Table 6 lists the results of the electronic absorption for the ligand (HAS) and complexes of the ligand within (10-4) molar in ethanol at room temperature, whereas Figures 10-14 explain their spectra. The synthesized complexes' electronic spectra revealed novel bands. The positions and intensities of these bands are primarily determined by depending on the ligand field effect, metal-ion electron configuration, and complex stereochemistry.
The UV-Vis spectrum of the ligand (HAS) in ethanol within the range(200-1100) nm, Figure 10 displays mainly two peaks. The first peak for (HAS) ligand is at (244 nm, 40983 cm-1). This peak was pointed to the mild energy (π → π*) transition of benzene, naphthalene rings. The (n → π*) transition of intramolecular charge transfer via the azo moiety was revealed by the second peak at (405 nm, 24691 cm-1) .
In the electronic spectra of para magnetic(2.74)B.M [Ni(HAS)2(H2O)2].4H2O complex, the (λmax) peak belongs to the ligand (HAS) was shifted as anticipated to higher wave length by (61) nm after coordination. Three d-d transitions were expected for paramagnetic high spin (d8) octahedral geometry .
υ1=3A2g (F) → 3T2g (F)
υ2=3A2g (F) → 3T1g (F)
υ3=3A2g (F) → 3T1g (P)
Figure 11 showed only two weak transitions υ1 at (893 nm; 11198 cm-1) and υ2 at (762nm; 13123 cm-1) for the [Ni(HAS)2(H2O)2].4H2O while the υ3 transition peak may be cryptic by the (LMCT) peak at (466nm; 21459 cm-1)
The complex [Co(HAS)2(H2O)2].4H2O Figure 12 appears two main transitions:
υ1 =4T1g(F) → 4T2g(F) at (982 nm; 10183 cm-1)
υ2=4T1g(F) → 4A1g(F) at (862 nm;11600 cm-1)
and also the third transition peak at (496nm; 20161 cm-1) was obscured by the complex peak[LMCT]. The complex had a distorted octahedral geometry with paramagnetic properties .
In the spectra of the diamagnetic low spin (d8) Pd (II) complex (Figure 13), for square planar surfaces, the three (d-d) transitions were highlighted 1A1g→1A2g, 1A1g→1B1g and 1A1g→1E1g .
Only two transitions were observed at (971 nm; 10298 cm-1 and 839 nm; 11918 cm-1) for [Pd(HAS)2].H2O which belongs to 1A1g→1A2g and 1A1g→1E1g while the transition 1A1g→1B1g is too weak to appear. But regarding the peak at (460 nm; 21739 cm-1) was attributed to LMCT.
The value of the magnetic measurement for low spin d8 Pt(II)- complexes is zero, which is approaching the value of the four-coordinate square planar geometry .
Two (d-d) transitions were shown in Figure 14 as explained below [Pt(HAS)2].5H2O .
1A1g → 1B1g (742 nm; 13477 cm-1)
1A1g → 1A2g (943 nm; 10604 cm-1 )
The peak at (443 nm; 22573 cm-1) was attributed to LMCT.
Thermo-gravimetric analysis (TGA)
TGA was used to investigate the temperature behavior of the synthesized ligand (HAS) and the complexes (Figures 15-19), while the number of stages changed. Calculated and discovered mass losses are given in Table 7. In our research, the weight loss followed up in the temperature range (25-1000) oC and subjected with argon flow. Thermal analysis is used to determine stoichiometry, thermal stability, and whether or not water molecules have crystallized or coordinated. The decomposed species were calculated using the weight losses for each constituent received from the thermal graph .
The results can be arranged as follows:
The results and the suggested formulae which is obtained from the analytical data seem to be identical.
- The thermogravimetric analysis data give an indication that the process of decomposition for the ligand (HAS) is carried out in several steps as well as their complexes.
- The thermal stability for HAS and its complexes was decreased as in the following order:
- HAS> [Ni(HAS)2(H2O)2].4H2O >[Co(HAS)2(H2O)2].4H2O > [Pd(HAS)2].H2O >[Pt(HAS)2 ].5H2O
Anti-oxidant and radical scavenging activity
Antioxidants help to stabilize a variety of goods, including meals, petrochemicals, medicines, and cosmetics and also help to strengthen an organism's defenses against free radical assaults. It can be found in both endogenous and exogenous forms in nature .
In vitro antioxidant of [Pt(HAS)2].5H2O was assessed using reductive ability and DPPH radical scavenging activity. In the reductive ability at all concentration (0.08, 0.16, 0.32, and 0.64) mg/mL for [Pt(HAS)2].5H2O was outperformed trolox (control) in the concentration-dependent reductive ability. It was (0.87167 ± 0.001528) at 0.08 mg/mL which was increased significantly to (1.66667 ± 0.005859) at 0.64 mg/mL (Table 8) indicating high reducibility for the complex when compared with trolox.
There is a lot of interest in creating a new form of synthetic chemical that is less hazardous and has no adverse effects. As a result of the current research using the DPPH test, the metal complex [Pt(HAS)2].5H2O was tested for its activity of scavenging. Figure 20 shows the scavenging effect of the tested chemicals at various doses, and it's clear that the action is reliant on coordination among the substances put to the test when compared to standard, the Pt (II) complex had good scavenging action, ascorbic acid used as control .
At the five concentrations which were examined (12.5, 25, 50, 100, and 200 mg/mL), [Pt(HAS)2].5H2O was substantially more active in DPPH radical scavenging activity than vitamin C. At concentrations of 12.5 mg/mL of [Pt(HAS)2].5H2O, it was (17.09± 1.857). At 200 mg/mL, DPPH radical scavenging activity increased dramatically to (72.62± 3.981). Table 9 and Figure 20 show the results.
The survey in Anticancer Effectiveness
At the concentration (400 𝜇𝑔/mL), [Pt(HAS)2].5H2O had high anti-liver cancer activity. The cytotoxic efficacy was shown to be 60.65% efficient in killing tumor cells. Treatment of HepG-2 cells with [Pt(HAS)2].5H2O for 24 hours resulted in a significant rise in cellular metal (Pt) concentration compared to the control (WRL68), suggesting that the complex was easily internalized within 24 hours. MTT test may be used to calculate percentages of dead cells. The cytotoxicity of [Pt(HAS)2].5H2O is determined by the cytotoxic impact of Pt(II) conjugated in suppression of HDAC (Histon deacetylases) enzyme, according to the mechanical recommendation covalently binds the positive charge on the histone tail's N-terminal groups of lysine and the phosphor groups in DNA to have a negative charge. The covalent binding of Histone to DNA is critical for gene expression .
The half-maximum inhibitory concentration (IC50) is used to determine the efficacy of a medicine. IC50 for the tested substance is (108.3) g/mL during a 24 hours incubation period. As a result, fewer medications are needed to promote cancer cell death, and hence patients can tolerate them Table 10 and Figure 21 show the results after incubation with HepG-2 and WRL68 cells lines for 24 hours at concentrations of (6.25,12.50,25,50,100,200 and 400) 𝜇𝑔/mL of the [Pt(HAS)2].5H2O complex; modifications of morphological for DNA inclusiveness were performed. Chromatin condensation and nucleus fragmentation with a production of apoptosis and drug resistance were demonstrated by the presence of apoptotic bodies.
Antibacterial and antifungal activity for the synthesized ligand and the complexes
Metal (II) complexes are more efficient than free ligands, as indicated in Table 11, indicating that the reactivity of metal ions with the ligand is significant in increasing antibacterial activity. The membrane's lipid that surrounds the cell allows only lipid-soluble molecules to pass through, making lipo solubility an important component in bacterial activity regulation . The examined compounds' method of action might include forming hydrogen bonds with infected cells' enzyme active sites via OH and/or N=N groups and effectively inhibiting them. Furthermore, the chemicals studied have the potential to disrupt organism respiration and impede protein synthesis. Variations in ribosomes in microbial cells or the impermeability of microbes' cells generate differences in the action of various complexes toward distinct species . Finally, the ligand and complexes have effectiveness toward Rhizopus microspores fungi, especially [Ni(HAS)2(H2O)2].4H2O .
The activity increases in this order for (E.coli) bacteria : [Pt(HAS)2].5H2O > HAS > [Pd(HAS)2].H2O > [Co(HAS)2(H2O)2].4H2O > [Ni(HAS)2(H2O)2].4H2O
and for (Staph) bacteria ,the activity increases in this following order : [Pt(HAS)2].5H2O > [Ni(HAS)2(H2O)2].4H2O > HAS > [Pd(HAS)2].H2O > [Co(HAS)2(H2O)2].4H2O
while the activity for Rhizopus microsporus fungus increases in the following order : [Ni(HAS)2(H2O)2].4H2O > [Co(HAS)2(H2O)2].4H2O > and [Pd(HAS)2].H2O > HAS > [Pt(HAS)2].5H2O.
Burns healing (anti-inflammatory)
Due to their broad therapeutic usefulness, sulfonamides have become an attractive scaffold. The anti-inflammatory medicines like celecoxib, as well as the antibacterial agents such as sulfamethoxazole and sulfadiazine, are all sulfonamides that are routinely employed as therapeutic agents .
The ability of [Co(HAS)2(H2O)2].4H2O at (1.5) mM silver sulfadiazine (positive control) and negative control to heal burns was investigated by determining the number of days required to recover the results (Table 12), revealed that [Co(HAS)2(H2O)2].4H2O complex was able to repair burns in 10 days in comparison with what is shown in Figures 22 and 23.
Performance of dying
Wool fiber includes a variety of polar groups, including –NH, –OH, and–SH groups. An amino group at the end of the chain, as well as a significant number of –NH groups, may be found in polyamide fiber .
The type of metal and its valence state, the concentration of a solution, pH, duration, temperature, and other variables, all influence the pace and extent of absorption. The nitrogen atoms of amino and amide groups can form coordination bonds, especially at alkaline pH .
Figure 24 showed the wool textile dyeing with the ligand (HAS) and the metal complexes; the color of wool textile were at the range between orange, red and brown.
Textile color fastness test for washing was carried out using soap with a concentration of 2%, and the results were very good (Table 13).
Acid - base indicator
Acid-base indicator is a chemical material used to determine if an aqueous solution is acidic, neutral, or alkaline in general. Because acidity and alkalinity affect pH, they are sometimes referred to as pH indicators, and their color changes as the pH changes. Azo dyes are one of the most widely utilized compounds as indicators because they have a squad of delocalization and bright hues, particularly yellow, red, and orange .
Based on the findings of spectral and analytical physicochemical investigations for the ligand (HAS) and its complexes, some conclusions have been achieved that lead to establishing the following points:
The ligand (HAS) was synthesized by the diazotization method with some modification and the ligand acted as neutral N, O-bidentate chelating ligand binds to the metal ions of interest. [Co(II), Ni(II), Pt(II), and Pd(II)], through the oxygen and nitrogen atoms of 7-Bromo 8-hydroxyquinoline, form a pentagonal chelating ring. Pt(II) and Pd(II) complexes are square planar, whereas Ni(II) complex is octahedral and Co(II) complex is distorted octahedral. A water molecule can be either coordination or crystalline. The synthesized complexes were characterized as high stability through examination of the stability constant and hot affected by moisture, light, and heat. Also through thermal analysis, the thermal stability of the produced compounds is shown by TGA. The ligand and the complexes have various anti-bacterial and anti-fungal activities. Some of the complexes are effective as anti-inflammatory, antioxidant, and anticancer. The ligand and the complexes can dye wool fabrics as they have different colors. The ligand (HAS) can change its color depending on the change in pH from acid to base which we can use it as an acid-base indicator.
This work was part of a research project of Duaa Jameel Jasim (M.Sc student) in (Science of Inorganic Chemistry, Department of Chemistry, College of Science, University of Baghdad, Baghdad, Iraq). And Supervised by Assistant professor Dr. Alyaa Khider Abbas
Alyaa Khider Abbas: http://orcid.org/0000-0002-8400-0926
How to cite this article: Duaa Jameel Jasim, Alyaa khider Abbas. Synthesis, identification, antibacterial, medical and dying performance studies for azo-sulfamethoxazole metal complexes. Eurasian Chemical Communications, 2022, 4(1), 16-40. Link: http://www.echemcom.com/article_141627.html