# New Platinum(IV) and Palladium(II) Transition Metal Complexes of s-Triazine Derivative: Synthesis, Spectral, and Anticancer Agents Studies

Authors: Fatima A. I. Al-Khodir; Hana M. A. Abumelha; Tarfah Al-Warhi; S. A. Al-Issa
Journal: BioMed Research International
 (2019)

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## Abstract

New Pd(II) and Pt(IV) triazine complexes [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L2)2(Cl)9(H2O)3].3Cl (2), [Pt3(L3)2(Cl)9(H2O)3].3Cl (3), [Pt2(L4)2(Cl)6(H2O)2] .2Cl.4H2O (4), [Pd3(L1)2(H2O)6] .3Cl2 (5), [Pd3(L2)2(H2O)6].3Cl2 (6), [Pd3(L3)2(H2O)6].3Cl2 (7), and [Pd2(L4)2(H2O)4].2Cl2 (8) were synthesized and well characterized using elemental analyses, molar conductance, IR, UV-Vis, magnetic susceptibility, 1H, 13C-NMR spectra, and thermal analyses. These analyses deduced that theL1,L2, andL3 ligands act as tridentate forming octahedral geometry with Pt(IV) metal ions and square planar geometry in case of Pd(II) complexes but theL4 ligand acts as bidentate chelate. The molar conductance values refer to the fact that all the prepared s-triazine complexes have electrolyte properties which are investigated in DMSO solvent. Surface morphology behaviors of prepared complexes have been scanned using TEM. The crystalline behavior of triazine complexes has been checked based on X-ray powder diffraction patterns. The antimicrobial activity of the free ligands and their platinum(IV) and palladium(II) complexes against the speciesStaphylococcus aureus (G+),Escherichia coli (G−),Aspergillus flavus, andCandida albicanshas been carried out and compared with the standard one. The coordination of ligands towards metal ions makes them stronger bacteriostatic agents, thus inhibiting the growth of bacteria and fungi more than the free ligands. The cytotoxic assessment IC50 of the free ligands and its platinum(IV) complexesin vitro against human colon and lung cancer cell lines introduced a promising efficiency.


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## Body

## 1. Introduction

The s-triazine and its derivatives have a wide range of pharmaceutical benefits: antiviral, antimalarial, antibacterial, anti-inflammatory, antileukemia, anticancer, and anti-HIV activities [1–4]. Many triazine analogues are utilized as a building block for the construction of multisite ligand systems [5, 6]. A number of triazine analogues were tested for ion extraction of metal ions which have been reviewed [7, 8]. Some triazine derivatives with pyrazole, functioning at the least conventional habiliments, are screened and identified as potential inhibitors of photosynthetic electron transport [9]. In literature survey, it was refereed that the organic s-triazine’s derivative compounds and transition metal complexes have been found to be effective in the field of nonlinear optical activity (NLO) [10–12] that can act as an auxiliary acceptor in NLO chromophores. Further advantages in considering the s-triazine as central moiety are its symmetric nature by which it will be possible to chemically tune its NLO nature by mono- or disubstitution [13, 14]. 1,3,5-Triazine is considered to be a remarkable in supramolecular chemistry since it can take part in all types of interactions, namely, coordination, hydrogen bonds, electrostatic and charge-transfer attractions, and aromatic-stacking interactions [15]. Triazine derivatives have been widely used in several fields such as herbicide [16, 17]. In materials chemistry 1,3,5-triazine derivatives have been used as acceptors in star-shaped systems [18], liquid crystals [19], redox active chromophores [20], photovoltaic devices [21], and blue phosphorescent [22]. Also, it was used as functional materials [23], catalysts [24], absorption of surfactants [25], nanoporous membranes for desalination [26], and cathodes for lithium batteries [27, 28].In connection of our previously work [29], this article aimed to synthesized new platinum(IV) and palladium(II) complexes with four triazine ligands (Figure 1) and checked the biological property and anticancer significance.Figure 1
Structures of prepared triazine ligands [29].L1= N2-(4-chlorophenyl)-N4,N6-di(pyrimidin-2-yl)-1,3,5-triazine-2,4,6-triamine.L2= N2-(4-chlorophenyl)-N4,N6-di(pyrimidin-2-yl)-1,3,5-triazine-2,4,6-triamine.L3=6-chloro-N2-(pyrimidin-2-yl)-N4-(1H-1,2,4-triazol-3-yl)-1,3,5-triazine-2,4-diamine.L4= 6-chloro-N2-(4-chlorophenyl)-N4-(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine).


## 2. Materials and Methods

### 2.1. Chemicals

The PtCl4 and PdCl2 salts were received from Sigma-Aldrich Chemical Corporation, St. Louis, Mo, USA.


### 2.2. Synthesis of Trisubstituted s-Triazine Derivative Ligands

Synthesis ofN2,N4,N6-triaryl-1,3,5-triazine-2,4,6-triamine primary nucleus (Figure 2) was carried out as described in literature [30, 31]. The synthesis ofL1,L2,L3, andL4 triazine ligands was carried out according to our previously work [29],L1 prepared by stirring the mixtures of 2-aminopyrimidine with 6-chloro-N2-(4-chlorophenyl)-N4-di(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine in dioxane at refluxed temperature;L2 prepared by stirring the mixtures of 2-aminothiazole with 6-chloro-N2-(4-chlorophenyl)-N4-(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine in dioxane at refluxed temperature;L3 prepared by stirring the mixtures of 2-aminopyrimidine with 4,6-dichloro-N2-(1H-1,2,4-triazol-3-yl)-1,3,5-triazin-2-amine in dioxane 50°C;L4 prepared by stirring the mixtures of 2-aminopyrimidine with 4,6-dichloro-N-( 4-chlorophenyl)-1,3,5-triazin-2-amine in dioxane 50°C.Figure 2
Synthesis of trisubstituted triazine derivatives.


### 2.3. Synthesis of Pt(IV) and Pd(II) Complexes

A hot methanolic solution of the metal chloride (Pt(IV) and Pd(II)) (1 mM) was added to the hot methanolic solution of ligands (L1,L2,L3, orL4) (1 mM). The mixed solutions were stirred and refluxed at 70°C for 6 hrs. The colored precipitates thus separated out were washed with methanol and dried invacuo.


### 2.4. Instrumentals

No. Type of analysis Model of the instruments (i) Elemental analyses Perkin Elmer CHN 2400 (USA) (ii) Metal ions gravimetrically (iii) Melting point MPS10–120 (iv) Molar conductivities Jenway 4010 conductivity meter (v) Infrared spectra Bruker Alpha FTIR Spectrophotometer (vi) UV-Vis absorption spectra UV2 Unicam UV/Vis Spectrophotometer (vii) Magnetic moments Magnetic Susceptibility Balance, Sherwood Scientific, Cambridge Science Park, Cambridge, England (viii) H   1,C13-NMR spectra Oxford YH-300 NMR spectrometer (ix) Mass spectra 70 eV using AEI MS 30 mass spectrometer (x) Thermal studies TG/DTG Mettler Toledo AG thermogravimetric analyzer (xi) SEM Quanta FEG 250 equipment (xii) XRD X 'Pert PRO PANanalytical X-ray powder diffraction (xiii) TEM JEOL 100s microscopy


### 2.5. Antimicrobial Study

Antimicrobial evaluations of the investigated samples were assessed by a modified Kirby-Bauer disc diffusion method [32, 33].


### 2.6. Anticancer Study

All tested samples were checked against human colon and lung cancer cell line by using neutral red (NR) technique [34].


## 2.1. Chemicals

The PtCl4 and PdCl2 salts were received from Sigma-Aldrich Chemical Corporation, St. Louis, Mo, USA.


## 2.2. Synthesis of Trisubstituted s-Triazine Derivative Ligands

Synthesis ofN2,N4,N6-triaryl-1,3,5-triazine-2,4,6-triamine primary nucleus (Figure 2) was carried out as described in literature [30, 31]. The synthesis ofL1,L2,L3, andL4 triazine ligands was carried out according to our previously work [29],L1 prepared by stirring the mixtures of 2-aminopyrimidine with 6-chloro-N2-(4-chlorophenyl)-N4-di(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine in dioxane at refluxed temperature;L2 prepared by stirring the mixtures of 2-aminothiazole with 6-chloro-N2-(4-chlorophenyl)-N4-(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine in dioxane at refluxed temperature;L3 prepared by stirring the mixtures of 2-aminopyrimidine with 4,6-dichloro-N2-(1H-1,2,4-triazol-3-yl)-1,3,5-triazin-2-amine in dioxane 50°C;L4 prepared by stirring the mixtures of 2-aminopyrimidine with 4,6-dichloro-N-( 4-chlorophenyl)-1,3,5-triazin-2-amine in dioxane 50°C.Figure 2
Synthesis of trisubstituted triazine derivatives.


## 2.3. Synthesis of Pt(IV) and Pd(II) Complexes

A hot methanolic solution of the metal chloride (Pt(IV) and Pd(II)) (1 mM) was added to the hot methanolic solution of ligands (L1,L2,L3, orL4) (1 mM). The mixed solutions were stirred and refluxed at 70°C for 6 hrs. The colored precipitates thus separated out were washed with methanol and dried invacuo.


## 2.4. Instrumentals

No. Type of analysis Model of the instruments (i) Elemental analyses Perkin Elmer CHN 2400 (USA) (ii) Metal ions gravimetrically (iii) Melting point MPS10–120 (iv) Molar conductivities Jenway 4010 conductivity meter (v) Infrared spectra Bruker Alpha FTIR Spectrophotometer (vi) UV-Vis absorption spectra UV2 Unicam UV/Vis Spectrophotometer (vii) Magnetic moments Magnetic Susceptibility Balance, Sherwood Scientific, Cambridge Science Park, Cambridge, England (viii) H   1,C13-NMR spectra Oxford YH-300 NMR spectrometer (ix) Mass spectra 70 eV using AEI MS 30 mass spectrometer (x) Thermal studies TG/DTG Mettler Toledo AG thermogravimetric analyzer (xi) SEM Quanta FEG 250 equipment (xii) XRD X 'Pert PRO PANanalytical X-ray powder diffraction (xiii) TEM JEOL 100s microscopy


## 2.5. Antimicrobial Study

Antimicrobial evaluations of the investigated samples were assessed by a modified Kirby-Bauer disc diffusion method [32, 33].


## 2.6. Anticancer Study

All tested samples were checked against human colon and lung cancer cell line by using neutral red (NR) technique [34].


## 3. Results and Discussion

### 3.1. Microanalytical and Physical Data

All the platinum(IV) and palladium(II) s-triazine derivative complexes were obtained as colored solids by the reaction of ligands (L1,L2,L3, andL4) with anhydrous metal chloride salts (PtCl4 and PdCl2). The experimental of elemental analyses of the ligands and their metal complexes (Table 1) are in good agreement with the calculated data. The ligands and their metal (IV/II) complexes are stable at room temperature and soluble in common organic solvents such as (DMSO and DMF). According to the elemental analysis and spectroscopic assignments, the chelating sites and geometry have been suggested and are displayed in Figure 3. The molar conductance of both free s-triazine derivative ligands and their Pt(IV) and Pd(II) complexes in 10−3 M of DMSO solution is in the range of 64.7–139.3 μS, which reveals the electrolytic behavior of the complexes [35]. Melting points of all complexes have values more than >300°C due to thermal stability properties.Table 1
Microanalytical and physicochemical data of ligands and their complexes.
Compounds∗ Color Λ(μS) Elemental analyses found(Calc.) Yield, % %C %H %N %M 1 Yellow 126.8 (21.44) (2.01) (14.71) (30.73) 77 21.32 1.96 14.57 30.66  2 Brown 70.6 (20.66) (1.63) (13.55) (31.46) 72 20.54 1.54 13.50 31.32  3 Green 64.7 (13.13) (1.22) (17.02) (35.55) 71 13.09 1.18 17.00 35.50  4 Pale yellow 95.6 (22.64) (2.19) (14.22) (28.29) 69 22.56 2.13 14.16 28.11  5 Dark brown 139.3 (28.64) (2.69) (19.65) (22.39) 75 28.56 2.57 19.54 22.31  6 Red brown 82 (26.77) (2.53) (17.56) (22.24) 70 26.71 2.51 17.49 22.19  7 Brownish green 106.7 (17.70) (2.15) (22.94) (26.14) 74 17.65 2.09 22.90 26.11  8 Brown 122.3 (30.49) (2.56) (19.15) (20.78) 71 30.41 2.49 19.12 20.69 ∗ [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L2)2(Cl)9(H2O)3].3Cl (2), [Pt3(L3)2(Cl)9(H2O)3].3Cl (3), [Pt2(L4)2(Cl)6(H2O)2] .2Cl.4H2O (4), [Pd3(L1)2(H2O)6].3Cl2 (5), [Pd3(L2)2(H2O)6].3Cl2 (6), [Pd3(L3)2(H2O)6] .3Cl2 (7) and [Pd2(L4)2(H2O)4].2Cl2 (8).Figure 3
Suggested structures of Pt(IV) and Pd(II) complexes.


### 3.2. FT-IR Spectra

Peaks at 1620, 1560, 1485, 740, and 627 cm−1 present inL1,L2,L3, andL4 s-triazine derivatives ligands can be assigned for the C=Npyrimidine, C=C, C=N, C–S, and C–Cl stretching vibrations. The FT-IR spectra of the ligands show a strong-to-medium strong bands at 1488 cm−1 (L1), 1485 cm−1 (L2), 1510 cm−1 (L3), and 1484 cm−1 (L4) which are assigned to ν(C=N) group of triazine [36]. Infrared spectral data of the1–8 complexes (Table 2; Figure 4) usually a lot of valuable information is provided about the coordination mechanism. The free ligands which exhibit a band at 1623 cm−1 (L1), 1619 cm−1 (L2), 1621 cm−1 (L3), and 1619 cm−1 (L4) are assigned to ν(C=N) of pyrimidine and triazole rings. In case of complexes, this band is shifted to 1698–1667 cm−1 region attributed to nitrogen atom of (C=N) coordination to metal ion. The ligands shows a medium strong band at 1510–1484 cm−1, which is characteristic of the ν(C=N) group in s-triazine [37, 38]. This band shifted to lower frequency of 1396–1382 cm−1 upon complexation which indicates that triazine ring nitrogen is one of the coordinating atoms in the ligand [38]. The ν(N–H) stretching frequency of pyrimidine/triazole rings exhibited at 3260–3112 cm−1 was shifted to lower wavenumbers after complexation due to the reduction of lone pair repulsive forces on the nitrogen atoms [39]. In the FT-IR spectra of complexes, the medium-weak bands appeared at 570–440 cm−1 regions which can be assigned to ν(M–N) [40] and confirm the interaction between metal and ligand.Table 2
FT-IR spectral band assignments ofL1, L2, L3, and L4 ligands and their complexes.
Compounds FTIR spectral assignments (cm−1) ν(N–H) ν(C=N)aromatic ν(C=C)aromatic ν(C=N)triazine ν(M–N) L 1 3249-3112 1623 1559 1488 -  L 2 3260-3142 1619 1555 1485 -  L 3 3251-3156 1621 1586 1510 -  L 4 3244-3150 1619 1574 1484 -  1 3200 1679 1560 1385 545, 447  2 - 1667 1537 1383 536, 441  3 - 1698 1585 1382 570, 470  4 - 1695 1567 1390 530, 469  5 - 1689 1530 1394 537, 440  6 - 1695 1557 1396 540, 463  7 - 1698 1550 1391 537, 467  8 - 1691 1537 1393 537, 463Figure 4
FT-IR spectra of (a) [Pt2(L4)2(Cl)6(H2O)2].2Cl.4H2O (4) and (b) [Pd3(L2)2 (H2O)6].3Cl2 (6).
(a) (b)


### 3.3. Electronic and Magnetic Studies

The electronic spectra of [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L2)2(Cl)9(H2O)3].3Cl (2), [Pt3(L3)2(Cl)9(H2O)3].3Cl (3), and [Pt2(L4)2(Cl)6(H2O)2] .2Cl.4H2O (4) complexes which displayed charge-transfer transitions may interfere and prevent the observation of all the expected bands [41, 42].The distinct bands at 300–311 and 337–396 cm−1 are attributed to a combination of metal ligand charge transfer (M→LCT) and d–d transition band. The other weak band at 429–437 cm−1 is attributed to combination of N→Pt(IV) metal charge transfer (Lπ→MCT) and d–d transition bands. The Pt(IV) complexes are found to be diamagnetic character, so the Pt(IV) complexes must be octahedral geometry. The Pt(IV) is d6 system and four bands are expected due to 1A1g→  3T1g, 1A1g→  3T2g, 1A1g→  1T1g, and 1A1g→  1T2g transitions. The shift to lower frequency after complexation is due to the binding between Pt(IV) ion nitrogen atom of triazine, pyrimidine, thiazole, and triazole rings. Palladium(II) complexes have diamagnetic properties. The electronic absorption spectra of palladium(II) complexes have distinguished bands at (300 nm), (312 and 352 nm), (309, 334 and 391 nm), and (296, and 339 nm) forL1,L2,L3, andL4 ligands, respectively, due to Pd-LnCT charge-transfer transitions.


### 3.4.1H, 13C-NMR Spectra

Complex 1. 1H-NMR (DMSO-d6): δ = 7.26 (t, H,J = 4.5 Hz, pyrimidineC5H), 7.30 (t, H,J = 4.5 Hz, pyrimidineC5H), 7.34 (d, 2H,J = 4.5 Hz,p-ChloroanilineC3H), 7.39 (d, 2H,J = 9.9 Hz,p-ChloroanilineC2H), 8.81 (d, 2H,J = 4.5 Hz, pyrimidineC4,6H), 8.91 (d, 2H,J = 4.5 Hz, pyrimidineC4,6H), 9.82 (s, 1H, NH), 11.19 (s, 1H, NH), 12.06 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 111.4, 113.8, 117.9, 123.9, 130.7, 140.1, 144.1, 147.5, 153.1, 157.1, 159.2, 163.4, 163.9, 166.2, and 169.7 (Ar-C, C=C, C=N).Complex 2. 1H-NMR (DMSO-d6): δ = 7.34 (d, 2H,J = 7.2 Hz, thiazoleC5H), 7.38 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.44 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.77 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.86 (d, 2H,J = 6.3 Hz, thiazoleC4H), 8.09 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.51 (s, 2H, NH), 11.18 (s, 2H, NH), 12.08 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 112.5, 114.0, 114.9, 123.2, 132.5, 145.2, 151.4, 152.9, 155.4, 157.0, 158.8, 162.0, 163.5, and 172.2 (Ar-C, C=C, C=N, C-S).Complex 3. 1H-NMR (DMSO-d6): δ = 7.23 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.32 (s, 2H, triazoleC5H), 8.45 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 8.91 (s, 2H, NH), 11.22 (s, 2H, NH), 11.46 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 115.8, 142.8, 146.5, 155.0, 156.2, 159.2, 163.8, 163.9, and 167.1 (Ar-C, C=C, C=N, C-Cl).Complex 4. 1H-NMR (DMSO-d6): δ = 7.35 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.39 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.44 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.76 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.50 (s, 2H, NH), 11.19 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 111.9, 118.0, 123.1, 132.4, 144.4, 147.9, 153.5, 156.8, 161.8, 166.6, and 172.1 (Ar-C, C=C, C=N, C-Cl).Complex 5. 1H-NMR (DMSO-d6): δ = 7.32 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.35 (t, 2H,J = 4.5 z, pyrimidineC5H), 7.41 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.46 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 8.57 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 7.79 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.19 (s, 2H, NH), 11.20 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 113.1, 115.1, 120.1, 123.8, 129.4, 141.7, 147.0, 149.8, 152.4, 157.7, 159.6, 163.1, 163.9, 165.8, and 171.1 (Ar-C, C=C, C=N).Complex 6. 1H-NMR (DMSO-d6): δ = 7.33 (d, 2H,J = 7.2 Hz, thiazoleC5H), 7.36 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.45 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.78 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.81 (d, 2H,J = 6.3 Hz, thiazoleC4H), 8.12 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.20 (s, 2H, NH), 12.02 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 110.2, 113.1, 115.8, 123.8, 131.8, 146.1, 150.3, 152.1, 155.0, 156.6, 158.1, 161.2, 163.1, and 173.4 (Ar-C, C=C, C=N, C-S).Complex 7. 1H-NMR (DMSO-d6): δ = 7.21 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.39 (s, 2H, triazoleC5H), 8.46 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 8.92 (s, 2H, NH), 11.20 (s, 2H, NH), 11.48 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 116.5, 141.9, 147.4, 154.4, 155.9, 159.8, 163.1, 164.5, and 168.8 (Ar-C, C=C, C=N, C-Cl).Complex 8. 1H-NMR (DMSO-d6): δ = 7.33 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.36 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.46 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.81 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.20 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 113.5, 119.2, 122.9, 130.5, 145.5, 149.4, 153.1, 157.4, 162.7, 165.6, and 171.8 (Ar-C, C=C, C=N, C-Cl).The1H-NMR spectral data of the synthesized Pt(IV) and Pd(II) complexes have been shifted to downfield because of formation metal chelating through the nitrogen atoms of triazine, pyrimidine, thiazole, and triazole rings.


### 3.5. Thermogravimetric Studies

Thermal analyses (TG-DTG) were performed under N2 atmosphere. The thermogravimetric and differential thermogravimetric curves of the synthesized Pt(IV) (1–4) and Pd(II) (5–8) complexes are shown in Figures 5 and 6. Table 3 refereed to the thermal decomposition assignments of all complexes from room temperature till 1000°C.Table 3
Thermo gravimetric data of Pt(IV) and Pd(II) triazine complexes.
Complexes D T G m a x Total weight loss Total residual Weight loss, % Assignments Residue, % Assignments 1 100 74 3H2O uncoord 26 PtO2 + Few carbons 300, 380, 600 2L1+6Cl2  2 100 70 3H2O coord 30 PtO2 + Few carbons 310, 380, 580 2L2+6Cl2  3 100 68 3H2O coord 32 PtO2 + Few carbons 370, 580, 700 2L3+6Cl2  4 100 72 4H2O uncoord 28 PtO2 + Few carbons 280, 380, 700 2L4+4Cl2+2H2O  5 230, 360, 620 75 2L1+3Cl2+6H2O 25 PdO + Few carbons  6 360, 420, 800 75 2L2+3Cl2+6H2O 25 PdO + Few carbons  7 300, 360, 650 78 2L3+3Cl2+6H2O 22 PdO + Few carbons  8 380, 620, 800 82 2L4+2Cl2+4H2O 18 PdO + Few carbonsFigure 5
TGA-DTG curves of Pt(IV) complexes1–4.
(a)
Complex1 (b)
Complex2 (c)
Complex3 (d)
Complex4Figure 6
TGA-DTG curves of Pd(II) complexes5–8.
(a)
Complex5 (b)
Complex6 (c)
Complex7 (d)
Complex8


### 3.6. X-Ray Diffraction Spectra

XRD diffraction patterns of the solid Pt(IV) and Pd(III) triazine complexes have been displayed in Figure7. The diffraction patterns of new Pt(IV) and Pd(II) complexes at 2θ values are (11.094, 13.585, 15.041, 15.840, 19.929, 22.276, 23.198, 30.360, 33.693, 39.780, 47.720°), (5.082, 12.894, 19.845, 29.786°), (12.861, 16.426, 17.438, 19.695, 22.031, 26.390, 35.265°), (13.078, 19.773, 29.893, 35.342, 45.307°), (16.712, 27.173, 28.562, 31756, 37.958, 45.472, 56.157, 57.440, 59.071°), (4.948, 10.051, 13.820, 16.705, 17.357, 19.608, 20.512, 24.738, 26.567, 27.247, 29.786, 37.806, 56.168, 57.332, 59.199°), (5.527, 11.110, 16.704, 18.605, 27.263, 28.547, 29.090, 33.708, 37.678, 51.690, 56.690, 56.193, 57.367, 59.096, 79.472°), and (16.839, 27.384, 28.680, 37.851, 48.826, 50.279, 56.287, 57.573, 59.194°) for the complexes1–8, respectively. The particle size was estimated using Scherrer’s equation [43]. The XRD patterns due to metallic platinum are agreement with JCPDS PDF card no. 04-0802 standard card [44] with (111), (200), (220) planes, respectively. Powder XRD patterns of Pd(II) complexes are shown in Figure 7. These spectra included distinguish patterns at 2θ = 37.678, 51.690, 59.096, and 79.472° assigned to (111), (200), (220), and (311) of Pd metal with fcc structure matching with JCPDS file no. 87-0638 [45]. This result confirms the presence of metallic Pd with fcc structure. The grain sizes of platinum(IV) and palladium(II) complexes are existed within 42–50 and nm according to highest distinguish peaks.Figure 7 (a)
XRD patterns of [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1) complex (b)
XRD patterns of [Pd3(L3)2(H2O)6] .3Cl2 (7) complex


### 3.7. Scanning and Transmission Electron Microscopes

The SEM photos of Pt(IV) and Pd(II) complexes1–8 are shown in Figure 8. These images reveal that the surface of all complexes is homogeneous with various morphological view because of the role of Pt(IV) and Pd(II) metal ions in the rearrangement of grains.Figure 8
SEM photos of Pt(IV) and Pd(II) complexes1–8.According to the TEM technique (Figure9), the average of particle size of platinum(IV) complexes existed within 15–92 nm.Figure 9
TEM photos of Pt(IV) complexes1–4.


### 3.8. Biological Studies

#### 3.8.1. Antibacterial Assessments

Table4 refers to the antibacterial activity of the free triazine ligands (L1,L2,L3, andL4) comparable with its platinum(IV) and palladium(II) complexes (1–8) againstStaphylococcus aureus (G+),Escherichia coli (G−), and fungi (Aspergillus flavus andCandida albicans). All complexes beside the four free ligands which have not any significant inhibitory against both respected fungi except for complexes of1,3,5,7, and8 have moderate inhibitory againstAspergillus flavus. All complexes have a moderate bacterial inhibitory in comparison with ampicillin standard drug. The variation in the activity of different metal complexes against different microorganisms depends on either the impermeability of the cells of the microbes or the differences in ribosomes in microbial cells [46, 47].Table 4
Inhibition zone diameter of free ligands and its Pt(IV) and Pd(II) complexes.
Sample Inhibition zone diameter (mm/mg Sample) Bacteria Fungi Escherichia coli  (G-) Staphylococcus aureus (G+) Aspergillus flavus (Fungus) Candida albicans (Fungus) Standard Ampicillin: Antibacterial agent 30 24 -- -- Amphotericin B: Antifungal agent -- -- 16 21  Control: DMSO 0.0 0.0 0.0 0.0  L 1 11 10 10 0.0  L 2 0.0 0.0 0.0 0.0  L 3 0.0 0.0 0.0 0.0  L 4 15 10 0.0 0.0  1 19 18 16 0.0  2 12 11 0.0 0.0  3 24 23 12 0.0  4 14 12 0.0 0.0  5 14 15 15 0.0  6 11 11 0.0 0.0  7 16 17 12 0.0  8 14 15 11 0.0 ∗Ampicillin and amphotericin B are standards of antibacterial and antifungal agents.


#### 3.8.2. Anticancer Assessments

Table5 and Figure 10 refer to the IC50 results of the free triazine ligands and its Pt(IV) complexes. From these data, it is clearly deduced that the [Pt3(L3)2(Cl)9(H2O)3].3Cl (3) complex has an efficiency against human colon and human lung cancer A549 cell lines rather than its corresponding freeL3 ligand.Table 5
IC50 activity of the free ligands and its Pt(IV) complexes.
Against human colon cancer cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  100 65 66 61 72.7 55.3 6.4 35.5 44.6  50 70 67.8 64.4 81.7 60 31.8 41.4 56.6  10 72 70 69.3 82.5 65 62.9 66.8 71.5  IC50 170 461 277 259 162.8 27 50.7 79  Against human lung cancer A549 cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  150 82.4 100 96 100 100 44.6 100 77.7  100 83.4 100 98.7 100 100 61.7 100 100  50 86 100 100 100 100 66.5 100 100  10 98.7 100 100 100 100 100 100 100  IC50 431.4 - 1305.7 - - 128 - 212Figure 10 (a)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human colon cancer cell lines (b)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human lung cancer A549 cell lines


## 3.1. Microanalytical and Physical Data

All the platinum(IV) and palladium(II) s-triazine derivative complexes were obtained as colored solids by the reaction of ligands (L1,L2,L3, andL4) with anhydrous metal chloride salts (PtCl4 and PdCl2). The experimental of elemental analyses of the ligands and their metal complexes (Table 1) are in good agreement with the calculated data. The ligands and their metal (IV/II) complexes are stable at room temperature and soluble in common organic solvents such as (DMSO and DMF). According to the elemental analysis and spectroscopic assignments, the chelating sites and geometry have been suggested and are displayed in Figure 3. The molar conductance of both free s-triazine derivative ligands and their Pt(IV) and Pd(II) complexes in 10−3 M of DMSO solution is in the range of 64.7–139.3 μS, which reveals the electrolytic behavior of the complexes [35]. Melting points of all complexes have values more than >300°C due to thermal stability properties.Table 1
Microanalytical and physicochemical data of ligands and their complexes.
Compounds∗ Color Λ(μS) Elemental analyses found(Calc.) Yield, % %C %H %N %M 1 Yellow 126.8 (21.44) (2.01) (14.71) (30.73) 77 21.32 1.96 14.57 30.66  2 Brown 70.6 (20.66) (1.63) (13.55) (31.46) 72 20.54 1.54 13.50 31.32  3 Green 64.7 (13.13) (1.22) (17.02) (35.55) 71 13.09 1.18 17.00 35.50  4 Pale yellow 95.6 (22.64) (2.19) (14.22) (28.29) 69 22.56 2.13 14.16 28.11  5 Dark brown 139.3 (28.64) (2.69) (19.65) (22.39) 75 28.56 2.57 19.54 22.31  6 Red brown 82 (26.77) (2.53) (17.56) (22.24) 70 26.71 2.51 17.49 22.19  7 Brownish green 106.7 (17.70) (2.15) (22.94) (26.14) 74 17.65 2.09 22.90 26.11  8 Brown 122.3 (30.49) (2.56) (19.15) (20.78) 71 30.41 2.49 19.12 20.69 ∗ [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L2)2(Cl)9(H2O)3].3Cl (2), [Pt3(L3)2(Cl)9(H2O)3].3Cl (3), [Pt2(L4)2(Cl)6(H2O)2] .2Cl.4H2O (4), [Pd3(L1)2(H2O)6].3Cl2 (5), [Pd3(L2)2(H2O)6].3Cl2 (6), [Pd3(L3)2(H2O)6] .3Cl2 (7) and [Pd2(L4)2(H2O)4].2Cl2 (8).Figure 3
Suggested structures of Pt(IV) and Pd(II) complexes.


## 3.2. FT-IR Spectra

Peaks at 1620, 1560, 1485, 740, and 627 cm−1 present inL1,L2,L3, andL4 s-triazine derivatives ligands can be assigned for the C=Npyrimidine, C=C, C=N, C–S, and C–Cl stretching vibrations. The FT-IR spectra of the ligands show a strong-to-medium strong bands at 1488 cm−1 (L1), 1485 cm−1 (L2), 1510 cm−1 (L3), and 1484 cm−1 (L4) which are assigned to ν(C=N) group of triazine [36]. Infrared spectral data of the1–8 complexes (Table 2; Figure 4) usually a lot of valuable information is provided about the coordination mechanism. The free ligands which exhibit a band at 1623 cm−1 (L1), 1619 cm−1 (L2), 1621 cm−1 (L3), and 1619 cm−1 (L4) are assigned to ν(C=N) of pyrimidine and triazole rings. In case of complexes, this band is shifted to 1698–1667 cm−1 region attributed to nitrogen atom of (C=N) coordination to metal ion. The ligands shows a medium strong band at 1510–1484 cm−1, which is characteristic of the ν(C=N) group in s-triazine [37, 38]. This band shifted to lower frequency of 1396–1382 cm−1 upon complexation which indicates that triazine ring nitrogen is one of the coordinating atoms in the ligand [38]. The ν(N–H) stretching frequency of pyrimidine/triazole rings exhibited at 3260–3112 cm−1 was shifted to lower wavenumbers after complexation due to the reduction of lone pair repulsive forces on the nitrogen atoms [39]. In the FT-IR spectra of complexes, the medium-weak bands appeared at 570–440 cm−1 regions which can be assigned to ν(M–N) [40] and confirm the interaction between metal and ligand.Table 2
FT-IR spectral band assignments ofL1, L2, L3, and L4 ligands and their complexes.
Compounds FTIR spectral assignments (cm−1) ν(N–H) ν(C=N)aromatic ν(C=C)aromatic ν(C=N)triazine ν(M–N) L 1 3249-3112 1623 1559 1488 -  L 2 3260-3142 1619 1555 1485 -  L 3 3251-3156 1621 1586 1510 -  L 4 3244-3150 1619 1574 1484 -  1 3200 1679 1560 1385 545, 447  2 - 1667 1537 1383 536, 441  3 - 1698 1585 1382 570, 470  4 - 1695 1567 1390 530, 469  5 - 1689 1530 1394 537, 440  6 - 1695 1557 1396 540, 463  7 - 1698 1550 1391 537, 467  8 - 1691 1537 1393 537, 463Figure 4
FT-IR spectra of (a) [Pt2(L4)2(Cl)6(H2O)2].2Cl.4H2O (4) and (b) [Pd3(L2)2 (H2O)6].3Cl2 (6).
(a) (b)


## 3.3. Electronic and Magnetic Studies

The electronic spectra of [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L2)2(Cl)9(H2O)3].3Cl (2), [Pt3(L3)2(Cl)9(H2O)3].3Cl (3), and [Pt2(L4)2(Cl)6(H2O)2] .2Cl.4H2O (4) complexes which displayed charge-transfer transitions may interfere and prevent the observation of all the expected bands [41, 42].The distinct bands at 300–311 and 337–396 cm−1 are attributed to a combination of metal ligand charge transfer (M→LCT) and d–d transition band. The other weak band at 429–437 cm−1 is attributed to combination of N→Pt(IV) metal charge transfer (Lπ→MCT) and d–d transition bands. The Pt(IV) complexes are found to be diamagnetic character, so the Pt(IV) complexes must be octahedral geometry. The Pt(IV) is d6 system and four bands are expected due to 1A1g→  3T1g, 1A1g→  3T2g, 1A1g→  1T1g, and 1A1g→  1T2g transitions. The shift to lower frequency after complexation is due to the binding between Pt(IV) ion nitrogen atom of triazine, pyrimidine, thiazole, and triazole rings. Palladium(II) complexes have diamagnetic properties. The electronic absorption spectra of palladium(II) complexes have distinguished bands at (300 nm), (312 and 352 nm), (309, 334 and 391 nm), and (296, and 339 nm) forL1,L2,L3, andL4 ligands, respectively, due to Pd-LnCT charge-transfer transitions.


## 3.4.1H, 13C-NMR Spectra

Complex 1. 1H-NMR (DMSO-d6): δ = 7.26 (t, H,J = 4.5 Hz, pyrimidineC5H), 7.30 (t, H,J = 4.5 Hz, pyrimidineC5H), 7.34 (d, 2H,J = 4.5 Hz,p-ChloroanilineC3H), 7.39 (d, 2H,J = 9.9 Hz,p-ChloroanilineC2H), 8.81 (d, 2H,J = 4.5 Hz, pyrimidineC4,6H), 8.91 (d, 2H,J = 4.5 Hz, pyrimidineC4,6H), 9.82 (s, 1H, NH), 11.19 (s, 1H, NH), 12.06 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 111.4, 113.8, 117.9, 123.9, 130.7, 140.1, 144.1, 147.5, 153.1, 157.1, 159.2, 163.4, 163.9, 166.2, and 169.7 (Ar-C, C=C, C=N).Complex 2. 1H-NMR (DMSO-d6): δ = 7.34 (d, 2H,J = 7.2 Hz, thiazoleC5H), 7.38 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.44 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.77 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.86 (d, 2H,J = 6.3 Hz, thiazoleC4H), 8.09 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.51 (s, 2H, NH), 11.18 (s, 2H, NH), 12.08 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 112.5, 114.0, 114.9, 123.2, 132.5, 145.2, 151.4, 152.9, 155.4, 157.0, 158.8, 162.0, 163.5, and 172.2 (Ar-C, C=C, C=N, C-S).Complex 3. 1H-NMR (DMSO-d6): δ = 7.23 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.32 (s, 2H, triazoleC5H), 8.45 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 8.91 (s, 2H, NH), 11.22 (s, 2H, NH), 11.46 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 115.8, 142.8, 146.5, 155.0, 156.2, 159.2, 163.8, 163.9, and 167.1 (Ar-C, C=C, C=N, C-Cl).Complex 4. 1H-NMR (DMSO-d6): δ = 7.35 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.39 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.44 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.76 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.50 (s, 2H, NH), 11.19 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 111.9, 118.0, 123.1, 132.4, 144.4, 147.9, 153.5, 156.8, 161.8, 166.6, and 172.1 (Ar-C, C=C, C=N, C-Cl).Complex 5. 1H-NMR (DMSO-d6): δ = 7.32 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.35 (t, 2H,J = 4.5 z, pyrimidineC5H), 7.41 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.46 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 8.57 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 7.79 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.19 (s, 2H, NH), 11.20 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 113.1, 115.1, 120.1, 123.8, 129.4, 141.7, 147.0, 149.8, 152.4, 157.7, 159.6, 163.1, 163.9, 165.8, and 171.1 (Ar-C, C=C, C=N).Complex 6. 1H-NMR (DMSO-d6): δ = 7.33 (d, 2H,J = 7.2 Hz, thiazoleC5H), 7.36 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.45 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.78 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.81 (d, 2H,J = 6.3 Hz, thiazoleC4H), 8.12 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.20 (s, 2H, NH), 12.02 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 110.2, 113.1, 115.8, 123.8, 131.8, 146.1, 150.3, 152.1, 155.0, 156.6, 158.1, 161.2, 163.1, and 173.4 (Ar-C, C=C, C=N, C-S).Complex 7. 1H-NMR (DMSO-d6): δ = 7.21 (t, 2H,J = 4.5 Hz, pyrimidineC5H), 7.39 (s, 2H, triazoleC5H), 8.46 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 8.92 (s, 2H, NH), 11.20 (s, 2H, NH), 11.48 (s, 1H, NH). 13C-NMR (DMSO-d6): δ = 116.5, 141.9, 147.4, 154.4, 155.9, 159.8, 163.1, 164.5, and 168.8 (Ar-C, C=C, C=N, C-Cl).Complex 8. 1H-NMR (DMSO-d6): δ = 7.33 (t, 4H,J = 4.5 Hz, pyrimidineC5H), 7.36 (d, 4H,J = 4.5 Hz,p-ChloroanilineC3H), 7.46 (d, 4H,J = 9.9 Hz,p-ChloroanilineC2H), 7.81 (d, 4H,J = 4.5 Hz, pyrimidineC4,6H), 9.55 (s, 2H, NH), 11.20 (s, 2H, NH). 13C-NMR (DMSO-d6): δ = 113.5, 119.2, 122.9, 130.5, 145.5, 149.4, 153.1, 157.4, 162.7, 165.6, and 171.8 (Ar-C, C=C, C=N, C-Cl).The1H-NMR spectral data of the synthesized Pt(IV) and Pd(II) complexes have been shifted to downfield because of formation metal chelating through the nitrogen atoms of triazine, pyrimidine, thiazole, and triazole rings.


## 3.5. Thermogravimetric Studies

Thermal analyses (TG-DTG) were performed under N2 atmosphere. The thermogravimetric and differential thermogravimetric curves of the synthesized Pt(IV) (1–4) and Pd(II) (5–8) complexes are shown in Figures 5 and 6. Table 3 refereed to the thermal decomposition assignments of all complexes from room temperature till 1000°C.Table 3
Thermo gravimetric data of Pt(IV) and Pd(II) triazine complexes.
Complexes D T G m a x Total weight loss Total residual Weight loss, % Assignments Residue, % Assignments 1 100 74 3H2O uncoord 26 PtO2 + Few carbons 300, 380, 600 2L1+6Cl2  2 100 70 3H2O coord 30 PtO2 + Few carbons 310, 380, 580 2L2+6Cl2  3 100 68 3H2O coord 32 PtO2 + Few carbons 370, 580, 700 2L3+6Cl2  4 100 72 4H2O uncoord 28 PtO2 + Few carbons 280, 380, 700 2L4+4Cl2+2H2O  5 230, 360, 620 75 2L1+3Cl2+6H2O 25 PdO + Few carbons  6 360, 420, 800 75 2L2+3Cl2+6H2O 25 PdO + Few carbons  7 300, 360, 650 78 2L3+3Cl2+6H2O 22 PdO + Few carbons  8 380, 620, 800 82 2L4+2Cl2+4H2O 18 PdO + Few carbonsFigure 5
TGA-DTG curves of Pt(IV) complexes1–4.
(a)
Complex1 (b)
Complex2 (c)
Complex3 (d)
Complex4Figure 6
TGA-DTG curves of Pd(II) complexes5–8.
(a)
Complex5 (b)
Complex6 (c)
Complex7 (d)
Complex8


## 3.6. X-Ray Diffraction Spectra

XRD diffraction patterns of the solid Pt(IV) and Pd(III) triazine complexes have been displayed in Figure7. The diffraction patterns of new Pt(IV) and Pd(II) complexes at 2θ values are (11.094, 13.585, 15.041, 15.840, 19.929, 22.276, 23.198, 30.360, 33.693, 39.780, 47.720°), (5.082, 12.894, 19.845, 29.786°), (12.861, 16.426, 17.438, 19.695, 22.031, 26.390, 35.265°), (13.078, 19.773, 29.893, 35.342, 45.307°), (16.712, 27.173, 28.562, 31756, 37.958, 45.472, 56.157, 57.440, 59.071°), (4.948, 10.051, 13.820, 16.705, 17.357, 19.608, 20.512, 24.738, 26.567, 27.247, 29.786, 37.806, 56.168, 57.332, 59.199°), (5.527, 11.110, 16.704, 18.605, 27.263, 28.547, 29.090, 33.708, 37.678, 51.690, 56.690, 56.193, 57.367, 59.096, 79.472°), and (16.839, 27.384, 28.680, 37.851, 48.826, 50.279, 56.287, 57.573, 59.194°) for the complexes1–8, respectively. The particle size was estimated using Scherrer’s equation [43]. The XRD patterns due to metallic platinum are agreement with JCPDS PDF card no. 04-0802 standard card [44] with (111), (200), (220) planes, respectively. Powder XRD patterns of Pd(II) complexes are shown in Figure 7. These spectra included distinguish patterns at 2θ = 37.678, 51.690, 59.096, and 79.472° assigned to (111), (200), (220), and (311) of Pd metal with fcc structure matching with JCPDS file no. 87-0638 [45]. This result confirms the presence of metallic Pd with fcc structure. The grain sizes of platinum(IV) and palladium(II) complexes are existed within 42–50 and nm according to highest distinguish peaks.Figure 7 (a)
XRD patterns of [Pt3(L1)2(Cl)9(H2O)3].3Cl.3H2O (1) complex (b)
XRD patterns of [Pd3(L3)2(H2O)6] .3Cl2 (7) complex


## 3.7. Scanning and Transmission Electron Microscopes

The SEM photos of Pt(IV) and Pd(II) complexes1–8 are shown in Figure 8. These images reveal that the surface of all complexes is homogeneous with various morphological view because of the role of Pt(IV) and Pd(II) metal ions in the rearrangement of grains.Figure 8
SEM photos of Pt(IV) and Pd(II) complexes1–8.According to the TEM technique (Figure9), the average of particle size of platinum(IV) complexes existed within 15–92 nm.Figure 9
TEM photos of Pt(IV) complexes1–4.


## 3.8. Biological Studies

### 3.8.1. Antibacterial Assessments

Table4 refers to the antibacterial activity of the free triazine ligands (L1,L2,L3, andL4) comparable with its platinum(IV) and palladium(II) complexes (1–8) againstStaphylococcus aureus (G+),Escherichia coli (G−), and fungi (Aspergillus flavus andCandida albicans). All complexes beside the four free ligands which have not any significant inhibitory against both respected fungi except for complexes of1,3,5,7, and8 have moderate inhibitory againstAspergillus flavus. All complexes have a moderate bacterial inhibitory in comparison with ampicillin standard drug. The variation in the activity of different metal complexes against different microorganisms depends on either the impermeability of the cells of the microbes or the differences in ribosomes in microbial cells [46, 47].Table 4
Inhibition zone diameter of free ligands and its Pt(IV) and Pd(II) complexes.
Sample Inhibition zone diameter (mm/mg Sample) Bacteria Fungi Escherichia coli  (G-) Staphylococcus aureus (G+) Aspergillus flavus (Fungus) Candida albicans (Fungus) Standard Ampicillin: Antibacterial agent 30 24 -- -- Amphotericin B: Antifungal agent -- -- 16 21  Control: DMSO 0.0 0.0 0.0 0.0  L 1 11 10 10 0.0  L 2 0.0 0.0 0.0 0.0  L 3 0.0 0.0 0.0 0.0  L 4 15 10 0.0 0.0  1 19 18 16 0.0  2 12 11 0.0 0.0  3 24 23 12 0.0  4 14 12 0.0 0.0  5 14 15 15 0.0  6 11 11 0.0 0.0  7 16 17 12 0.0  8 14 15 11 0.0 ∗Ampicillin and amphotericin B are standards of antibacterial and antifungal agents.


### 3.8.2. Anticancer Assessments

Table5 and Figure 10 refer to the IC50 results of the free triazine ligands and its Pt(IV) complexes. From these data, it is clearly deduced that the [Pt3(L3)2(Cl)9(H2O)3].3Cl (3) complex has an efficiency against human colon and human lung cancer A549 cell lines rather than its corresponding freeL3 ligand.Table 5
IC50 activity of the free ligands and its Pt(IV) complexes.
Against human colon cancer cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  100 65 66 61 72.7 55.3 6.4 35.5 44.6  50 70 67.8 64.4 81.7 60 31.8 41.4 56.6  10 72 70 69.3 82.5 65 62.9 66.8 71.5  IC50 170 461 277 259 162.8 27 50.7 79  Against human lung cancer A549 cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  150 82.4 100 96 100 100 44.6 100 77.7  100 83.4 100 98.7 100 100 61.7 100 100  50 86 100 100 100 100 66.5 100 100  10 98.7 100 100 100 100 100 100 100  IC50 431.4 - 1305.7 - - 128 - 212Figure 10 (a)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human colon cancer cell lines (b)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human lung cancer A549 cell lines


## 3.8.1. Antibacterial Assessments

Table4 refers to the antibacterial activity of the free triazine ligands (L1,L2,L3, andL4) comparable with its platinum(IV) and palladium(II) complexes (1–8) againstStaphylococcus aureus (G+),Escherichia coli (G−), and fungi (Aspergillus flavus andCandida albicans). All complexes beside the four free ligands which have not any significant inhibitory against both respected fungi except for complexes of1,3,5,7, and8 have moderate inhibitory againstAspergillus flavus. All complexes have a moderate bacterial inhibitory in comparison with ampicillin standard drug. The variation in the activity of different metal complexes against different microorganisms depends on either the impermeability of the cells of the microbes or the differences in ribosomes in microbial cells [46, 47].Table 4
Inhibition zone diameter of free ligands and its Pt(IV) and Pd(II) complexes.
Sample Inhibition zone diameter (mm/mg Sample) Bacteria Fungi Escherichia coli  (G-) Staphylococcus aureus (G+) Aspergillus flavus (Fungus) Candida albicans (Fungus) Standard Ampicillin: Antibacterial agent 30 24 -- -- Amphotericin B: Antifungal agent -- -- 16 21  Control: DMSO 0.0 0.0 0.0 0.0  L 1 11 10 10 0.0  L 2 0.0 0.0 0.0 0.0  L 3 0.0 0.0 0.0 0.0  L 4 15 10 0.0 0.0  1 19 18 16 0.0  2 12 11 0.0 0.0  3 24 23 12 0.0  4 14 12 0.0 0.0  5 14 15 15 0.0  6 11 11 0.0 0.0  7 16 17 12 0.0  8 14 15 11 0.0 ∗Ampicillin and amphotericin B are standards of antibacterial and antifungal agents.


## 3.8.2. Anticancer Assessments

Table5 and Figure 10 refer to the IC50 results of the free triazine ligands and its Pt(IV) complexes. From these data, it is clearly deduced that the [Pt3(L3)2(Cl)9(H2O)3].3Cl (3) complex has an efficiency against human colon and human lung cancer A549 cell lines rather than its corresponding freeL3 ligand.Table 5
IC50 activity of the free ligands and its Pt(IV) complexes.
Against human colon cancer cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  100 65 66 61 72.7 55.3 6.4 35.5 44.6  50 70 67.8 64.4 81.7 60 31.8 41.4 56.6  10 72 70 69.3 82.5 65 62.9 66.8 71.5  IC50 170 461 277 259 162.8 27 50.7 79  Against human lung cancer A549 cell lines  Concentration (μg/mL) Viability (%) L 1 1 L 2 2 L 3 3 L 4 4  150 82.4 100 96 100 100 44.6 100 77.7  100 83.4 100 98.7 100 100 61.7 100 100  50 86 100 100 100 100 66.5 100 100  10 98.7 100 100 100 100 100 100 100  IC50 431.4 - 1305.7 - - 128 - 212Figure 10 (a)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human colon cancer cell lines (b)
Images of the neutral red cytotoxicity test of the freeL1,L2,L3, andL4 ligands and their Pt(IV) complexes (1–4) against human lung cancer A549 cell lines



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