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

New Pd(II) and Pt(IV) triazine complexes [Pt3(L 1 )2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L 2 )2(Cl)9(H2O)3].3Cl (2), [Pt3(L 3 )2(Cl)9(H2O)3].3Cl (3), [Pt2(L 4 )2(Cl)6(H2O)2] .2Cl.4H2O (4), [Pd3(L 1 )2(H2O)6] .3Cl2 (5), [Pd3(L 2 )2(H2O)6].3Cl2 (6), [Pd3(L 3 )2(H2O)6].3Cl2 (7), and [Pd2(L 4 )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 the L 1 , L 2 , and L 3 ligands act as tridentate forming octahedral geometry with Pt(IV) metal ions and square planar geometry in case of Pd(II) complexes but the L 4 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 species Staphylococcus aureus (G+), Escherichia coli (G-), Aspergillus flavus, and Candida albicans has 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) complexes in vitro against human colon and lung cancer cell lines introduced a promising efficiency.

1. Introduction

The s-triazine and its derivatives have a wide range of phn class="Chemical">armaceutical 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 n class="Chemical">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].= N-(4-chlorophenyl)-N,N-di(pyrimidin-2-yl)-1,3,5-triazine-2,4,6-triamine.= N-(4-chlorophenyl)-N,N-di(pyrimidin-2-yl)-1,3,5-triazine-2,4,6-triamine.=6-chloro-N-(pyrimidin-2-yl)-N-(1H-1,2,4-triazol-3-yl)-1,3,5-triazine-2,4-diamine.= 6-chloro-N-(4-chlorophenyl)-N-(pyrimidin-2-yl)-1,3,5-triazine-2,4-diamine).

2. Materials and Methods

2.1. Chemicals

The PtCl4 and n class="Chemical">PdCl2 salts were received from Sigma-Aldrich Chemical Corporation, St. Louis, Mo, USA.

2.2. Synthesis of Trisubstituted s-Triazine Derivative Ligands

Synthesis of N,N,N-triaryl-n class="Chemical">1,3,5-triazine-2,4,6-triamine primary nucleus (Figure 2) was carried out as described in literature [30, 31]. The synthesis of L, L, L, and L triazine ligands was carried out according to our previously work [29], L 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; L 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; L 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; L 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 n class="Chemical">metal chloride (Pt(IV) and Pd(II)) (1 mM) was added to the hot methanolic solution of ligands (L, L, L, or L) (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 in vacuo.

2.4. Instrumentals

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 n class="Disease">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 n class="Chemical">palladium(II) s-triazine derivative complexes were obtained as colored solids by the reaction of ligands (L, L, L, and L) 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(L)2(Cl)9(H2O)3].3Cl.3H2O (1), [Pt3(L)2(Cl)9(H2O)3].3Cl (2), [Pt3(L)2(Cl)9(H2O)3].3Cl (3), [Pt2(L)2(Cl)6(H2O)2] .2Cl.4H2O (4), [Pd3(L)2(H2O)6].3Cl2 (5), [Pd3(L)2(H2O)6].3Cl2 (6), [Pd3(L)2(H2O)6] .3Cl2 (7) and [Pd2(L)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 in L, L, L, and L s-triazine derivatives ligands can be assigned for the C=n class="Chemical">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 (L), 1485 cm−1 (L), 1510 cm−1 (L), and 1484 cm−1 (L) which are assigned to ν(C=N) group of triazine [36]. Infrared spectral data of the 1–8 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 (L), 1619 cm−1 (L), 1621 cm−1 (L), and 1619 cm−1 (L) 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 of L, L, L, and L 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, 463

Figure 4

FT-IR spectra of (a) [Pt2(L)2(Cl)6(H2O)2].2Cl.4H2O (4) and (b) [Pd3(L)2 (H2O)6].3Cl2 (6).

3.3. Electronic and Magnetic Studies

The electronic spectra of [Pt3(L)2(Cl)9(n class="Chemical">H2O)3].3Cl.3H2O (1), [Pt3(L)2(Cl)9(H2O)3].3Cl (2), [Pt3(L)2(Cl)9(H2O)3].3Cl (3), and [Pt2(L)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) for L, L, L, and L ligands, respectively, due to Pd-LnCT charge-transfer transitions.

3.4. 1H, 13C-NMR Spectra

Complex . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.26 (t, H, J = 4.5 Hz, pyrimidine CH), 7.30 (t, H, J = 4.5 Hz, pyrimidine CH), 7.34 (d, 2H, J = 4.5 Hz, p-Chloroaniline CH), 7.39 (d, 2H, J = 9.9 Hz, p-Chloroaniline CH), 8.81 (d, 2H, J = 4.5 Hz, pyrimidine CH), 8.91 (d, 2H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.34 (d, 2H, J = 7.2 Hz, thiazole CH), 7.38 (t, 4H, J = 4.5 Hz, pyrimidine CH), 7.44 (d, 4H, J = 4.5 Hz, p-Chloroaniline CH), 7.77 (d, 4H, J = 9.9 Hz, p-Chloroaniline CH), 7.86 (d, 2H, J = 6.3 Hz, thiazole CH), 8.09 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.23 (t, 2H, J = 4.5 Hz, pyrimidine CH), 7.32 (s, 2H, triazole CH), 8.45 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.35 (t, 4H, J = 4.5 Hz, pyrimidine CH), 7.39 (d, 4H, J = 4.5 Hz, p-Chloroaniline CH), 7.44 (d, 4H, J = 9.9 Hz, p-Chloroaniline CH), 7.76 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.32 (t, 2H, J = 4.5 Hz, pyrimidine CH), 7.35 (t, 2H, J = 4.5 z, pyrimidine CH), 7.41 (d, 4H, J = 4.5 Hz, p-Chloroaniline CH), 7.46 (d, 4H, J = 9.9 Hz, p-Chloroaniline CH), 8.57 (d, 4H, J = 4.5 Hz, pyrimidine CH), 7.79 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.33 (d, 2H, J = 7.2 Hz, thiazole CH), 7.36 (t, 4H, J = 4.5 Hz, pyrimidine CH), 7.45 (d, 4H, J = 4.5 Hz, p-Chloroaniline CH), 7.78 (d, 4H, J = 9.9 Hz, p-Chloroaniline CH), 7.81 (d, 2H, J = 6.3 Hz, thiazole CH), 8.12 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.21 (t, 2H, J = 4.5 Hz, pyrimidine CH), 7.39 (s, 2H, triazole CH), 8.46 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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 . 1H-NMR (n class="Chemical">DMSO-d6): δ = 7.33 (t, 4H, J = 4.5 Hz, pyrimidine CH), 7.36 (d, 4H, J = 4.5 Hz, p-Chloroaniline CH), 7.46 (d, 4H, J = 9.9 Hz, p-Chloroaniline CH), 7.81 (d, 4H, J = 4.5 Hz, pyrimidine CH), 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).

The 1H-NMR spectral data of the synthesized n class="Chemical">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 n class="Chemical">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.

Figure 5

TGA-DTG curves of Pt(IV) complexes 1–4.

Figure 6

TGA-DTG curves of Pd(II) complexes 5–8.

Table 3

Thermo gravimetric data of Pt(IV) and Pd(II) triazine complexes.

Complexes	DTGmax	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 carbons

3.6. X-Ray Diffraction Spectra

XRD diffraction patterns of the solid Pt(IV) and n class="Chemical">Pd(III) triazine complexes have been displayed in Figure 7. 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 complexes 1–8, 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

3.7. Scanning and Transmission Electron Microscopes

The SEM photos of Pt(IV) and n class="Chemical">Pd(II) complexes 1–8 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) complexes 1–8.

According to the TEM technique (Figure 9), the average of particle size of n class="Chemical">platinum(IV) complexes existed within 15–92 nm.

Figure 9

TEM photos of Pt(IV) complexes 1–4.

3.8. Biological Studies

3.8.1. Antibacterial Assessments

Table 4 refers to the antibacterial activity of the free triazine ligands (L, L, L, and L) compn class="Chemical">arable with its platinum(IV) and palladium(II) complexes (1–8) against Staphylococcus aureus (G+), Escherichia coli (G−), and fungi (Aspergillus flavus and Candida albicans). All complexes beside the four free ligands which have not any significant inhibitory against both respected fungi except for complexes of 1, 3, 5, 7, and 8 have moderate inhibitory against Aspergillus 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

Table 5 and Figure 10 refer to the IC50 results of the free triazine ligands and its n class="Chemical">Pt(IV) complexes. From these data, it is clearly deduced that the [Pt3(L)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 free L 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	-	212

Figure 10

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)	1H,13C-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