IHJPAS. 36(2)2023 259 This work is licensed under a Creative Commons Attribution 4.0 International License. Abstract This work describes the synthesis of novel ligand (H2L2) (4-((2-hydroxy-5- nitrophenyl)imino)methyl)-5(hydroxymethyl)-2methylpyridin-3-ol) type (NOO) donor atoms. When it coordinates with metal ions[V2+,Mn2+,Fe2+,Co2+,Ni2+,Cu2+and Pt4+] with the general formula K2[M(L 2)2].XH2O and K2[VO(L 2)(OSO3)].H2O . This ligand can form tridentate structures. The ligand was synthesized from the reaction of pyridoxal hydrochloride with 2-amino- 4-nitrophenol in ethanol (as a solvent) at a mole ratio of 1:1 and thoroughly mixed and refluxed for 6-8 hrs . The reaction was monitored using TLC (Ethylactate/hexane 1:1). The structures of the ligand and the complexes were characterised using spectroscopic techniques such as (FT-IR, 1HNMR, 13CNMR, UV-Vis, and Mass spectroscopy). In addition, molar conductance, magnetic susceptibility, elemental analysis, and thermo gravimetric, melting points were also measured for complexes. The antibacterial activities of the obtained products were tested against G- bacteria (Klebsiella pneumoniae and pseudomonas), G+ bacteria (Staphylococcus aureus and Bacillus subtilis). In addition, antifungal action was tested against (Candida albicans). The results were good in both tests. keywords: donor atoms, ligand, pyridoxal hydrochloride. doi.org/10.30526/36.2.3054 Article history: Received 1 October 2022, Accepted 24 October 2022, Published in April 2023. Ibn Al-Haitham Journal for Pure and Applied Sciences Journal homepage: jih.uobaghdad.edu.iq Synthesis a Novel Complexes of VO(II),Mn(II),Fe(II) ,Co(II), Ni(II), Cu(II)and Pt(IV) Derived from Schiff’s Base of Pyridoxal and 2-amino-4-nitrophenol and Study their Biological Activates Ahmed A. Ismail Department of Chemistry, College of Education for Pure Science Ibn Al-Haitham, University of Baghdad, Baghdad, Iraq. chem3ps@gmail.com Sajid M. Lateef Department of Chemistry, College of Education for Pure Science, University of Diyala, Diyala, Iraq. sajidm1957@gmail.com https://creativecommons.org/licenses/by/4.0/ mailto:sajidm1957@gmail.com IHJPAS. 36(2)2023 260 1. Introduction Heterocyclic compounds are a part of organic compounds in which it is contain hetero atoms in addition to carbon in their aromatic ring, the atoms could be nitrogen, sulfur and oxygen [1]. There are numerous heterocyclic compounds that may be synthesized in the laboratory and may have significant properties as variables[2]. Heterocyclic compounds are a big group of organic chemicals because of their biological properties such as anti-bacterial, anti-fungal, anti- inflammatory, and anti-cancer properties. [3] The use of nitrogen-containing heterocycles compounds are in medicine, industry, and agriculture attracts attention of the many researchers [4]. Schiff base that derived from pyridoxal consist an important class of heterocyclic compounds and being the core structure in several natural product and which have biological applications [5]. The nitro phenol compounds were utilized in the reactions as intermediates especially in the pharmaceuticals, pesticides, dyes and wood preservation. Environmental degradation of 2,4- dinitrophenol lead to form o-amino-p-nitrophenol which can be used as a fungicide for wood [6]. Schiff’s base complexes contains a variety of central metal atoms, including Cu, Ni, Co, and Pt, have been extensively reported for their diverse crystallographic properties, enzymatic reactions, mesogenic properties, catalystic and magnetic properties, as well as their critical role in the interpreting the transition metal coordination in chemistry[7]. 2. Materials and method Several different methods and devices were used to characterize the targeted compounds. These are Melting Point, FT-IR spectrophotometry, Conductivity, UV.Vis photometer in the area of (400-1100) nm, Mass spectrophotometry, Metal Analysis, Elemental analysis, Magnetic Moment Measurement, 1H and 13C-NMR photometer and Thermal Gravimetric Analysis TGA. The biological activity of the prepared compounds was then evaluated towards (Klebsiella pneumoniae and pseudomonas) (G-), two bacteria (Staphylococcus aureus and Bacillus subtilis) (G+), and one fungus (Candida albicans). 2.1. Synthesis of ligand H2L2: The solution of pyridoxal hydrochloride (2.03g, 0.01mol) in ethanol was added to the solution of 2-amino-4-nitrophenol (0.151g, 0.01mol) in the same solvent at a mole ratio of 1:1 and thoroughly mixed. To correct the pH (pH = 7-8), catalytic 0.1% alcoholic NaOH was added to the reaction mixture, and the reaction was heated under reflux for 6–8 hour [8]. The TLC silica gel was used for monitored the reaction eluent (1:1 Ethylactate/hexane). A solid mass of dark brown hue that formed during reflux and was cooled to room temperature and then, washed with IHJPAS. 36(2)2023 261 ethanol to give 86% yield as reddish brown, m.p:100-102 oC , Mw:303.27 C14H13N3O5, Synthesis route of the ligand [H2L 2] shown in Equation (1). .]2L2Equation (1): synthesis route of the ligand [H 2.2. FT-IR spectra of starting materials and the ligand H2L2 2.2.1. Analysis of FT-IR spectra: 2.2.1.1. Spectrum of Pyridoxal: Figure (S1) shows band at 3259 cm-1 belongs to O-H group, bands at 3047 cm-1 for C-H aromatic and at 2978 cm-1 due to C-H aliphatic. The band at 1643 cm-1 refers to C=O, the strong band at 1554 cm-1 belong to the frequency of C=N in the ring and the band at 1442 cm-1 is for aromatic C=C. The two bands at 1284 and 783 cm-1 refers to C-O and C-O that exist in the compound [9]. see table 1. 2.2.1.2. FT-IR spectrum of 2-amino-4-nitrophenol (ANPH): Two sharps bands appeared at 3471 and 3387 cm-1 for NH2 group, and the band at 1635 cm-1 and a strong band at 1581 refers to N-H bending and C=N respectively [10], aromatic C=C appeared at 1523 cm-1. Moreover, band of C-N is located at 1338 cm-1. The two bands at 1292 and 779 cm-1 assigned for two C-O [11]. see table 1. 2.2.1.3. FT-IR spectrum for ligand H2L2: The spectrum of (H2L 2) showed in figure (S1), band at 3356 cm-1 is for O-H group. The C-H aromatic appeared at 3070 cm-1. The stretching frequency of the imine group (C=N) appeared at 1620 cm-1 and band at 1581 cm-1 belong to C=N within the group [12]. The aromatic C=C appeared at 1496 cm-1 and band at 1334 cm-1 assigned for C-N. The bands at 1288 and 744 cm-1 refers to both C-O. see table 1. IHJPAS. 36(2)2023 262 Figure(S1): FT-IR spectrum of the H2L2 Table (1): Infra-red data (cm-1) for the starting materials and the ligand Compounds υ(O- H) υasy(NH2) υsy(NH2) υ(C=O) υ(C-H) aro. υ(C-H) ali. υ(C=N) imine υ(C=N) in plane υ(C-N) υ(C - O) δ(C - O) Pyridoxal 3259 - 1643 3047 2978 - 1554 - 1284 783 ANPH - 3471 3387 - 3047 2997 - 1581 1338 1292 779 H2L2 3356 - - - 3070 2985 1620 1581 1334 1288 744 2.3. The Mass spectra of H2L2: The molecular ion peak for the ligand is observed at m/z+ =303[M]. =C14H13N3O5; requires = 303.09[13]. The peaks detected at m/z+ = 285 correspond to [C14H11N3O4] +̇ - [H2O] The fragmentation pattern of (H2L 2) is tabulated in Table (2). See scheme 1 for proposed fragmentation of (H2L 2). Table (2): The fragments pattern of [H2L2] H2L2 FRAGMENTS FORMULA Mwt Abundance [M]. C14H13N3O5 303 2109597.6 [M1] +̇ = [M] .- H2O C14H11N3O4 285 82038.9 [M2] +̇ = [M1] +̇ - O C14H11N3O3 269 16579.8 [M3] + = [M2] +̇ - CH C13H10N3O3 256 40586.4 [M4] +̇ = [M3] + - C5H2N C8H8N2O3 180 271210.2 [M5] +̇ = [M4] +̇ - NH C8H7NO3 165 661036.3 IHJPAS. 36(2)2023 263 [M6] +̇ = [M5] +̇ - C C7H7NO3 153 1398016 [M7] + = [M6] +̇ - CH3 C6H4 NO3 138 644713.6 [M8] +̇ = [M7] + - N C6H4 O3 124 821425.8 [M9] +̇ = [M8] + - O C6H4 O2 108 4600451.6 [M10] +̇ = [M9] +̇ - C C5H4 O2 96 1913392.6 [M11] +̇ = [M10] +̇ - O C5H4O 80 3456116.7 [M12] + = [M11] +̇ - OH C5H3 63 2108557.6 [M13] + = [M12] + - C C4H3 51 4095603 2.4. 1H-NMR spectrum for the ligand H2L2 1H-NMR spectrum for (H2L 2) displayed the peaks at 7.22–6.79 ppm as multiple are assignable to aromatic ring protons (Ar–CH)[14] . The signal at 8.19 ppm was assigned for the proton of (N=CH), and the signal at 8.86 ppm was resonated to the protons of (N–CH) ring. Peak at 4.98-4.82 ppm belongs to the protons of (CH2O) group. The signal at 8.39 ppm was attributed to the proton of O-H. Peak at 2.35ppm is for protons of CH3 group[6]. See table (3). Table (3): 1H-NMR data for [H2L2] Compound Functional group δ (ppm) H2L2 N͞͞͞͞ ̶ CH 8.86 N=CH 8.19 OH 8.39 Ar–CH 7.22–6.79 O-CH2 4.96 and 4.88 CH3 2.35 HDO 3.62 DMSO 2.32 2.5. 13C-NMR spectrum for H2L2: 13C-NMR spectrum of (H2L 2) shows peaks at 113.51-140.47 ppm assigned for aromatic carbon atoms, while the peak at 158.23 ppm attributed to carbon of imine group (C7)[14]. The peak at 197.52 ppm attributed to the (C8), while carbon (C9) of (C–O–H) appeared at 172.28 ppm. The chemical shifts at 176.10 ppm is for (C10) of (C-CH3), whereas peak of carbon C11 of aromatic C- N was at 158.55 ppm. The chemical shift at 65.90 ppm attributed to the carbon C13 of (CH2 –OH), and shift at 13.76ppm attributed to the (C14) of (CH3) group [6]. See table (4). Table (4): 13C-NMR data of [H2L2] Compound Functional group δ (ppm) H2L2 C8 197.52 C10 176.10 C7 158.23 C1 – C6 113.51-140.47 DMSO 40.41 – 39.40 C14 13.76 IHJPAS. 36(2)2023 264 2.6. Electronic spectrum of (H2L2) ligand: The electronic spectrum for (H2L 2) exhibited 4 absorption peaks at (276nm,36232 cm-1) with (312nm, 32051 cm-1) assigned to ( π → π* ) transition and ( 368nm , 27174 cm-1 ) and (463nm , 21598 cm-1 ) is due to (n→ π*) and (LLCT) transition [16]. The data of absorption of the ligand (H2L 2) were arranged in the table (5). Table (5): Electronic data of the ligand Ligand (nm) – (cm–1) max (molar -1cm-1) transitions H2L2 276 36232 412 ᴫ → ᴫ* 312 32051 362 ᴫ → ᴫ* 368 27174 358 n→ ᴫ* 463 21598 726 LLCT 2.7. Preparation of (H2L2 )complexes(1-7): 2.7.1. Synthesis of K2[VO(L2)(OSO3)].H2O (1) An ethanolic solution of [H2L 2] (0.03g, 1mmole). A solution of KOH (1 g/mmole) was formed, and then was added drop by drop to a Vanadyl (II) sulphate monohydrate (0.0181g, 1mmole) dissolved in (10ml) ethanol. After letting the reaction mixture reflux for ( 3 hrs.). The dark brown product was obtained, washed several times with EtOH and dried to give the complex in 91% yield, M.P : (260-262ºC). 2.7.2. Synthesis of K2[Mn(L2)2].H2O (2), K2[Fe(L2)2].H2O (3), K2[Co(L2)2].H2O(4),K2[Ni(L2)2].H2O (5) , K2[Cu(L2)2].H2O (6) , and [Pt(L2)2].2H2O (7). Using the mentioned method in the synthesis of VO(II) complex, was used to synthesize the complexes of [H2L 2] with H2PtCl6 , MCl2.nH2O M(II)=[ Mn (n=4), Co (n=6), Ni (n=6), Cu (n=2), Fe (n=4), and Pt (n=0) ] ions. For the physical properties see table (6). complexes] 2L2H[ ligand physical properties of: Table(6) No. Formula Color Molecular formula of mineral salt Wt of metal salt (1mmol.) 1 K2[VO(L 2)(OSO3)].H2O Dark brown VOSO4.H2O 0.018 g 2 K2 [Mn(L 2)2].H2O Dark brown MnCl2.4H2O 0.020 g 3 K2 [Fe(L 2)2].H2O Reddish brown FeCl2.4H2O 0.020 g 4 K2 [Co(L 2)2].H2O reddish brown CoCl2.6H2O 0.024 g 5 K2 [Ni(L 2)2].H2O Reddish brown NiCl2.6H2O 0.0238 g 6 K2 [Cu(L 2)2].H2O Dark brown CuCl2.2H2O 0.0171 g 7 [Pt(L2)2].2H2O brown H2PtCl6 0.040g IHJPAS. 36(2)2023 265 3. Results and discussion: Some of the physical characteristics of novel ligand and its complexes are tabulated in table (7). The results from the elemental analysis were listed with the mathematical calculations. Table (7): Molecular weights of the ligand (H2L2)complexes(1-7) and the results of elemental microanalysis. C o m p le x e s.N o Compounds M.wt g/mol Found / calc. % C H N S metal K 1 K2[VO(C14H11N3O5)(OSO3)].H2O 560 29.71 2.29 7.39 5.60 8.99 13.82 30.00 2.32 7.50 5.71 9.10 13.92 2 K2 [Mn(C14H11N3O5)2].H2O 753 44.49 3.16 10.92 7.19 10.28 44.62 3.18 11.15 - 7.30 10.35 3 K2 [Fe(C14H11N3O5)2].H2O 754 44.39 3.16 10.96 7.29 10.24 44.56 3.18 11.14 - 7.40 10.30 4 K2 [Co(C14H11N3O5)2].H2O 757 43.98 3.11 10.96 7.62 10.22 44.38 3.17 11.09 - 7.79 10.31 5 K2 [Ni(C14H11N3O5)2].H2O 756.7 43.96 3.11 10.97 7.59 10.19 44.40 3.16 11.10 - 7.74 10.30 6 K2 [Cu(C14H11N3O5)2].H2O 761.5 43.89 3.10 10.92 8.21 10.11 44.12 3.15 11.03 - 8.33 10.24 7 [Pt(C14H11N3O5)2].2H2O 833 40.22 3.08 9.96 22.96 - 40.33 3.12 10.08 - 23.40 Calc.= Calculated 3.1. Molar conductance and the physical properties of the ligand H2L2 complexes (1-7): Table (8): The molar conductivity values and physical properties of H2L2 ligand Complexes(8-14) C o m p le x e s N o . Complexes Yield % M.p. ºC m.c s.cm2 /mol Ratio ionic 1 K2[VO(L 2)(OSO3)].H2O 91 >250 73.06 2:1 2 K2 [Mn(L2)2].H2O 88 180 Dec 74.31 2:1 3 K2 [Fe(L2)2].H2O 82 283-240 79.16 2:1 4 K2 [Co(L2)2].H2O 89 162-164 78.04 2:1 5 K2 [Ni(L2)2].H2O 85 >250 75.21 2:1 6 K2 [Cu(L 2)2].H2O 88 158-160 75.42 2:1 7 [Pt(L2)2].2H2O 79 240 Dec 18.46 neutral IHJPAS. 36(2)2023 266 3.2. Magnetic susceptibility of ligand's H2L2 complexes : The effective magnetic moments (µeff B.M) of the metal complexes were measured in the solid state using Faraday's method[16] . Pt(IV) complex is diamagnetic in nature, because of 5d6, suggesting low spin octahedral geometry[17]. Table (9): The effective magnetic moment (µeff) values for complexes (1-7) C o m p le x e s N o . COMPLEXES Xg x 10-6 Xm x 10-6 XAx 10-6 No.of unpaired Electron µeff B.M str u c tu r e 1 K2[VO(L 2)(OSO3)].H2O 1.820 1019.200 1247.88 1 1.73 Sq.Py 2 K2 [Mn(L 2)2].H2O 15.960 12017.880 12439.49 5 5.46 Oh. 3 K2 [Fe(L 2)2].H2O 0.00 0.00 0.00 0 0.00 LS oh 4 K2 [Co(L 2)2].H2O 12.342 9342.894 9764.50 3 4.84 Oh. 5 K2 [Ni(L 2)2].H2O 3.648 2760.441 3182.05 2 2.76 Oh. 6 K2 [Cu(L 2)2].H2O 1.190 906.185 1327.79 1 1.78 Oh. D= - 421.61 ˣ 10-6, Sq. Py = square pyramid, LS = low spin 3.3. FT-IR spectra of ligand's [H2L2] complexes (1-7): The infra-red spectra for the synthesized compounds 1-7 are listed in table (10). Which shows that some guide bands in spectra for ligand H2L 2 are changed of their position or shape on coordination with metal ion. The infra-red spectra of the prepared complexes were compared to of H2L 2 this was to determine when ligands were involved in the chelation step [18]. The band of the stretch frequency of the azomethine C=N group of free ligand was appeared at 1620 cm-1, but for the obtained complexes the same band was shifted either lower or higher frequencies in the range of 1614-1627 cm-1, and this shift might have related to the coordination of the metal ions to the nitrogen atom of the azomethine group. The stretch vibration band at 1581 cm-1 is belong to C=N group of thiazole ring of free ligand, and was shifted to range of 1539-1585 cm-1 for all complexes, confirming the coordination between metal ions and nitrogen atoms C=N group [19]. The bands at 1249-1265 cm-1 and at 744-756 cm-1 of complexes 1-7, were attributed to both C-O group of phenolic compounds, which were shifted to a lower or higher frequencies on comparison to the free ligand (H2L 2) at 1288 and 744 cm-1. This shift is due to the coordination of the phenolic oxygen atom to metal ion [20]. The broad band in infra-red spectra for the complexes 8-14 were assigned to hydrate H2O [21]. For the complex of VO (II) the new band was appeared at 999 cm -1 and attributed to the V=O vibration [22]. Other new bands for the of infra-red spectrum of complex VO(II) were at 1045, 981 and 663 cm-1 are corresponding to SO4 -2 group, and this indicating that the SO4 -2 is participated in the coordination to the VO(II) ion which behave as monodentate ligand. In the out of plane region, the infra-red spectra displayed additional bands they were absent in the IHJPAS. 36(2)2023 267 spectra of the free ligand. These bands are located between 594 and 516 cm-1 and assigned to (M- N) bond. In contrast, the bands located between 478 and 428 cm-1 are designated as (M-O) [23]. Table (10):FT-IR data (cm-1) of the ligand [H2L2] and complexes. N o . c o m p le x e s Compounds O-H C-O C=N imine C=N in plane M - N M - O # H2L 2 3356 1288 1620 1581 - - 744 1 K2[VO(L 2)(OSO3)].H2O 3421 1261 1616 1577 582 438 732 2 K2 [Mn(L 2)2].H2O 3332 1292 1627 1576 551 478 736 3 K2 [Fe(L 2)2].H2O 3471 1284 1616 1593 532 428 740 4 K2 [Co(L 2)2].H2O 3417 1292 1615 1585 516 447 748 5 K2 [Ni(L 2)2].H2O 3441 1275 1616 1577 594 478 732 6 K2 [Cu(L 2)2].H2O 3417 1276 1614 1574 520 442 732 7 [Pt(L2)2].2H2O 3329 1241 1631 1558 555 448 748 3.4. Electronic spectrum of (H2L2) ligand complexes (1-7): The electronic data for complexes 1-7 are listed in table (11) along with electronic transition and proposed geometrical shapes. The spectra for the complexes 1-7 displayed 3 to 5 signals at a range 266-448nm, (37594-22321cm-1) and were attributed to intra-ligand, which shows shifting to lower and higher wave length on comparing to the (H2L 2) free ligand. Such shifting confirmed the coordination of (H2L 2) ligand to the central ion [24]. In addition, the spectra of complexes1-7 displayed a new intense absorption within the range of 402-463nm. Moreover, peaks at 24876-21589 cm-1 were assigned to M→LCT electronic transition [25]. IHJPAS. 36(2)2023 268 Table (11): Electronic spectral data for [H2L2]and its complexes. C o m p le x e s N o . Compound (nm) –(cm–1) max molar -1 /cm Electronic transitions p r o p o se d S tr u c tu r e # H2L 2 276 36232 412 ᴫ → ᴫ* - 312 32051 362 ᴫ → ᴫ* 368 27174 358 n→ ᴫ* 463 21598 726 LLCT 1 K2[VO(L 2)(OSO3)].H2O 270 37037 905 Intra-ligand Sq.py. 306 32680 843 Intra-ligand 365 27397 1145 Intra-ligand 381 26247 852 Intra-ligand 445 22472 782 MLCT 548 18248 108 2B2→ 2B1 706 14164 19 2B2→ 2E 2 K2 [Mn(L 2)2].H2O 271 36900 1644 Intra-ligand Oh. 307 32573 1543 Intra-ligand 315 31746 1522 Intra-ligand 345 28986 1873 Intra-ligand 404 24752 1475 Intra-ligand 420 23810 1497 MLCT 518 19305 412 6A1g → 4T2g (G) 578 17301 108 6A1g → 4T1g (G) 3 K2 [Fe(L 2)2].H2O 279 35842 787 Intra-ligand L.S.Oh. 310 32258 648 Intra-ligand 346 28902 685 Intra-ligand 452 22124 1347 MLCT 636 15723 18 1A1g → 1T2g 833 12005 10 1A1g→ 1T1g 1070 9346 14 1A1g → 3T2g 4 K2 [Co(L 2)2].H2O 268 37313 878 Intra-ligand Oh. 310 32258 526 Intra-ligand 344 29070 586 Intra-ligand 402 24876 640 MLCT  540 18519 72 4T1g(F)→ 4T1g (P) 760 13158 44 4T1g(F)→ 4A2g(F) 894 11186 43 4T1g(F)→ 4T2g(F) 5 K2 [Ni(L 2)2].H2O 266 37594 917 Intra-ligand Oh. 308 32468 648 Intra-ligand 345 28986 904 Intra-ligand 406 24631 843 Intra-ligand 463 21598 1015 MLCT+ 3A2g(F→ 3T1g(P) 622 16077 41 3A2g(F)→ 3T1g(F) IHJPAS. 36(2)2023 269 961 10406 20 3A2g(F)→ 3T2g (F) 6 K2 [Cu(L 2)2].H2O 270 37037 1293 Intra-ligand Dist.Oh 310 32258 1282 Intra-ligand 345 28986 1642 Intra-ligand 388 25773 1153 Intra-ligand 421 23753 1260 MLCT 534 18727 108 2B1g → 2B2g 734 13624 60 2B1g → 2A1g 7 [Pt(L2)2].2H2O 271 36900 1912 Intra-ligand Oh. 312 32051 994 Intra-ligand 350 28571 993 Intra-ligand 359 27855 634 Intra-ligand 425 23529 504 MLCT 643 15552 32 1A1g → 1T2g 833 12005 28 1A1g → 1T1g 3.5. Thermal analysis : In Table(12) the thermal decomposition data of metal complex [Co(L2)2]. H2O are listed, figure (S2) showed curves discuss. In this work, the title compound is studied using a variety methods for analysis, such as Thermo-Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Table (12): TG and DSC data for [Co(L2)2].H2O complex. Complex Stage Decomposition Temperatures (ºC) Estimated (calculated) Assignment Mass Loss Total mass Loss [Co(L2)2].H2O 1 217 0.313 4.973 (5.281) - (H2O, CO, H2) (0.353) 2 304 1.846 - (N2, C4H6O, 2CO2, NH3, C6H5, H2) (1.926) 3 619 0.738 - (C5H4O3) (0.801) 4 above 619 2.076 - (K2CoC10N3O) IHJPAS. 36(2)2023 270 Figure (S2): TGA and DSC thermos-gram of [Co(L2)2]. H2O 3.6. Anti-bacterial Activity: The biological activities of novel ligand H2L 2 and the obtained complexes have evaluated against gram-positive and gram-negative bacterial strains and some fungi species. The antibacterial activity for the synthesized compounds was tested against four types of bacteria (Klebsiella pneumonia, pseudomonas, Staphylococcus aureus and Bacillus subtilis), and the results of the tests are listed in table (13). Figure (S3) to Figure (S6) illustrates the inhibition area for the synthesised compounds on dishes, and shows that it have different antibacterial activities [26]. 3.7. Anti-fungal Activity: The anti-fungal activity for the obtained compounds were tested against Candida albicans. The results of tests are listed in the table (13) and shows a good effect. Figure (S8)[27]. Table (13): The biological activity of desired compounds Compound K.pneumoniae Pseudomonas B. subtilis St. aureus Candida albicans H2L2 15 22 11 16 13 K2[VO(L 2)(OSO3)].H2O 20 19 26 18 13 K2 [Mn(L 2)2].H2O 7 18 16 9 15 K2 [Fe(L 2)2].H2O 7 22 13 10 20 K2 [Co(L 2)2].H2O 20 18 17 20 15 K2 [Ni(L 2)2].H2O 27 17 26 16 13 K2 [Cu(L 2)2].H2O 7 20 14 9 15 [Pt(L2)2].2H2O 6 21 18 9 16 DMSO 0 0 0 0 0 Fluconazole - - - - 22 Ceftriaxone 15 12 13 13 - IHJPAS. 36(2)2023 271 Figure( S3): Effect of (H2L 2) and it's complexes against (Bacillus subtilus) Figure (S4): Effect of (H2L 2) and it's complexes against (Staphylococcus aureus) Figure (S5): Effect of (H2L 2) and it's complexes against (Klebsiella pneumoniae) IHJPAS. 36(2)2023 272 Figure (S6): Effect of (H2L 2) and it's complexes against (Pseudomonas aeruginosa) Figure (S7): Anti-bacterial activities against four types of bacteria Figure (S8): Effect of (H2L 2) and it's complexes against (Candida albicans) 0 5 10 15 20 25 30 Klebsiella pneumoniae Pseudomonas Bacillus subtilis Staphylococcus aureus IHJPAS. 36(2)2023 273 Figure (S9): Anti-fungal activities of against candida albicans 4. 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