Synthesis, Characterization, Thermodynamics and Anticancer Studies of New Tetraaza and Triaza Schiff Base Ligands and Their Metal Complexes of Ni(II), Cu(II), Co(II) and Zn(II)

1.1. General introduction…………………………………………………………..

2

     1.1.1. Inorganic compounds…………………………………………………

2

     1.1.2. Coordination chemistry………………………………………………

4

     1.1.3. Ligand………………………………………………………………………

5

1.2. Schiff bases……………………………………………………………………..

5

     1.2.1. Hugo Schiff: from Germany to Italy………………………………

6

     1.2.2. Schiff base ligands……………………………………………………….

6

…..1.2.3. Schiff base metal complexes…………………………………………

12

     1.2.4. Applications of Schiff base transition metal complexes….

15

     1.2.5. Methods for Characterization of Schiff base Compounds.

17

…..1.2.6. Aza Schiff base compounds………………………………………….

19

1.3. Quinoline…………………………………………………………………………..

25

     1.3.1. Quinoline substituted compounds………………………………….

26

1.4. Chemistry of Metals……………………………………………………………

31

     1.4.1. Transition Metals………………………………………………………….

31

          1.4.1.1 Copper…………………………………………………………………

31

          1.4.1.2. Cobalt…………………………………………………………………

33

          1.4.1.3. Nickel…………………………………………………………………

33

          1.4.1.4. Zinc…………………………………………………………………….

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1.5. Ligand substitution reaction…………………………………………………

37

1.6. Thermodynamics and inorganic chemistry…………………………….

38

     1.6.1. Formation constant………………………………………………………

38

     1.6.2. Spectrophotometric Methods…………………………………………

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1.7. The Objective of This Project

40

2.1. Materials……………………………………………………………………………

43

2.2. Physical measurements………………………………………………………..

43

2.3. The synthesis of new tetraaza Schiff base compounds…………….

44

     2.3.1. Synthesis of tetraaza Schiff base ligands (L¹-L³)……………..

44

     2.3.2. Synthesis of tetraaza Schiff base ligands (L⁴-L⁶)……………..

45

     2.3.3. Synthesis of tetraaza Schiff base ligands (L⁷, L⁸)…………….

46

2.4. The synthesis of new triaza Schiff base compounds………………..

46

     2.4.1. The synthesis of new triaza Schiff base ligands……………….

47

2.5. Synthesis of tetraaza Schiff base complexes…………………………..

51

2.6. Synthesis of triaza Schiff base complexes………………………………

53

2.7. Thermodynamic studies……………………………………………………….

61

     2.7.1. The studies of formation constants and free energies of tetraaza Schiff base ligands (L¹-L³) consisting of linear bridge with MCl₂.4H₂O. ( M²⁺ = Co²⁺, Cu²⁺, Ni²+, Zn²⁺)……………………………..

61

     2.7.2. The studies of formation constants and free energies of tetraaza Schiff base ligands (L⁴-L⁸) consisting of cyclic bridge with MCl₂.4H₂O. ( M²⁺ = Co²⁺, Cu²⁺, Ni²⁺, Zn²⁺)………………………..     2.7.3. The studies of formation constants and free energies of triaza Schiff base ligands (L⁹, L¹⁰) consisting of cyclic bridge with MCl₂.4H₂O. ( M²⁺ = Cu²⁺, Ni²⁺, Zn²⁺).

63

64

3.1. General informations…………………………………………………………..

66

3.2. The characterization of ligands and complexes……………………….

69

     3.2.1. The molar conductance…………………………………………………

69

     3.2.2. The melting oint………………………………………………………….

71

     3.2.3. The elemental analysis…………………………………………………

72

     3.2.4. The infrared spectroscopy…………………………………………….

80

     3.2.5. The UV-Vis spectroscopy…………………………………………….

91

     3.2.6. The ¹H-NMR spectroscopy…………………………………………..

98

3. 3. Thermodynamic aspects and literature review

106

     3.3.1. Thermodynamic studies of the complex formation for the tetraaza Schiff base ligands cotaining linear diamine with Co²⁺, Cu²⁺, Ni²⁺ and Zn²⁺ ions in methanol……………………………………….

          3.3.1.1. The effect of metal upon complex formation……………

          3.3.1.2. The effect of diamine bridge in ligands upon complex formation……………………………………………………………………….

114

114

115

     3.3.2. Thermodynamic studies of the complex formation for the tetraaza Schiff base ligands cotaining aromatic diamine with Co²⁺, Cu²⁺, Ni²⁺ and Zn²⁺ ions in methanol…………………………….

116

          3.3.2.1. The electronic effect of the ligands upon complex formation……………………………………………………………………….

116

          3.3.2.2. The metal effect upon the complex formation with tetraaza Schiff base………………………………………………………….

117

     3.3.3. Thermodynamic studies of the complex formation for the triaza Schiff base ligands cotaining aromatic diamine with Cu²⁺, Ni²⁺ and Zn²⁺ ions in methanol……………………………………………..

119

          3.3.3.1. The electronic effect of the ligands upon complex formation……………………………………………………………………….

120

          3.3.3.2. The metal effect upon the complex formation with triaza Schiff base ……………………………………………………………

120

3.4. Biological activities of Schiff base compounds.

121

     3.4.1 Cytotoxicity…………………………………………………………………

139

3.5. Analytical Applications of Schiff base Compounds

141

3.6. Conclusions

150

SCHEME

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Scheme 1.1. Synthesise of macrocyclic complexes …………………….

22

Scheme 1.2. Synthesis of ligand……………………………………………….

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Scheme 2.1. Synthesis of tetraaza Schiff base ligands (L¹-L³)………

45

Scheme 2.2. Synthesis of tetraaza Schiff base ligands (L⁴-L⁶)……..

45

Scheme 2.3. Synthesis of tetraaza Schiff base ligands (L⁷, L⁸)……..

46

Scheme 2.4. Synthesis of new triaza Schiff base ligands (L⁹, L¹⁰)…

47

Scheme 2.5. Synthesis of tetraaza Schiff base complexes……………

53

Scheme 2.6. Synthesis of triaza Schiff base complexes……………….

54

Scheme 3.1. Synthesis of new Schiff base tetraaza ligands………….

67

Scheme 3.2. Synthesis of new Schiff base triaza ligands……………..

68

Table 3.1. Analytical and physical data of the tetraaza ligands……….

74

Table 3.2. Analytical and physical data of the Ni(II) complexes…….

75

Table 3.3. Analytical and physical data of the Cu(II) complexes…….

76

Table 3.4. Analytical and physical data of the Zn(II) complexes…….

77

Table 3.5. Analytical and physical data of the Co(II) complexes…….

78

Table 3.6. Analytical and physical data of the triaza ligands and their complexes……………………………………………………………….

79

Table 3.7. IR characterization of the tetraaza Schiff base ligands …..

83

Table 3.8. IR characterization of the Ni(II) complexes …………………

84

Table 3.9. IR characterization of the Cu(II) complexes ………………..

85

Table 3.10. IR characterization of the Zn(II) complexes ………………

86

Table 3.11. IR characterization of the Co(II) complexes ………………

87

Table 3.12. IR characterization of the triaza ligands and their complexes …………………………………………………………………….

88

Table 3.13. UV-Vis bands λ _max (MeOH/nm) of L¹ to L⁸ and nickel complexes……………………………………………………………………..

96

Table 3.14. UV-Vis bands λ _max (MeOH/nm) of copper and zinc complexes……………………………………………………………………..

97

Table 3.15. UV-Vis bands λ _max (MeOH/nm) of L⁹ and L¹⁰ and their complexes…………………………………………………………………….

98

Table 3.16. ¹H-NMR data of the triaza Schiff bases and their complexes…………………………………………………………………….

102

Table 3.17. ¹H-NMR data of the tetraaza Schiff bases and their complexes………………………………………………………………………

103

Table 3.18. The formation constants, log K_f, and the free energies, ∆Gº, for the complexes of the ligands with Ni²⁺ and Cu²⁺ ions at 25ºC, in MeOH………………………………………………..

118

Table 3.19. The formation constants, log K_f, and the free energies, ∆Gº, for the complexes of the ligands with Zn²⁺ and Co²⁺ ions at 25ºC, in MeOH…………………………………………………….

119

Table 3.20. The formation constants, log K_f, and the free energies, ∆Gº,for the complexes of the triaza ligands with the M²⁺ ions at 25ºC, in MeOH……………………………………………………………

121

Table 3.21. Cell growth inhibitory activity of compounds in vitro .

140

Figure 1.1. Synthesis of Schiff base……………………………………………

7

Figure 1.2. Some examples of Schiff bases………………………………….

8

Figure 1.3. Chemical structure of fluorescent Schiff bases…………….

9

Figure 1.4. N₂O₂ Schiff base compounds…………………………………….

10

Figure 1.5. Macrocyclic Schiff base compounds………………………….

11

Figure 1.6. Binding modes of small molecules with DNA…………….

17

Figure 1.7. Chemical structures of Schiff bases with silver ion discrimination ability……………………………………………………

20

Figure 1.8. Chemical structure of MoO₂pypr catalys……………………

20

Figure 1.9. Mono and bis benzimidazoles derivatives…………………..

21

Figure 1.10. Schiff base tetraazamacrocyclic ligand……………………

23

Figure 1.11. Macrocyclic Schiff base for stabilizing of various oxidation states……………………………………………………………..

24

Figure 1.12. L¹ and L² ligands……………………………………………………

25

Figure 1.13. Tetraaza ligands…………………………………………………….

27

Figure 1.14. On–off–on’ fluorescent indicators……………………………

29

Figure 1.15. Chemical structure of the ligand 2-quinoline-N-(2`-methylthiophenyl) methyleneimine wity N,N,S donor atoms

28

Figure 1.16. Chemical structure of Schiff base ligands by changing pendant arms………………………………………………………………..

29

Figure 1.17. Transition metal catalysts……………………………………….

30

Figure 1.18. Bis-bidentate Schiff base ligands……………………………..

30

FIGURES

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Figure 2.1. N, Nˊ-bis(2-quinolylmethylidene)-1,2-ethanediimine…..

48

Figure 2.2. N, Nˊ-bis(2-quinolylmethylidene)-1,2-propanediimine…

48

Figure 2.3. N, Nˊ-bis(2-quinolylmethylidene)-1,3-propanediimine…

49

Figure 2.4. N, Nˊ-bis(2-quinolylmethylidene)-4-methy-1, 2-phenylenediimine………………………………………………………….

49

Figure 2.5. N, Nˊ-bis(2-quinolylmethylidene)-4-methoxy-1, 2-phenylenediimine………………………………………………………….

50

Figure 2.6. N, Nˊ-bis(2-quinolylmethylidene)-4-chloro-1, 2-phenylenediimine………………………………………………………….

50

Figure 2.7. N, Nˊ-bis(2-quinolylmethylidene)-4-carboxylic-1, 2-phenylenediimine………………………………………………………….

51

Figure 2.8. N, Nˊ-bis(2-quinolylmethylidene)-4-nitro-1, 2-phenylenediimine………………………………………………………….

51

Figure 2.9. N-(2-quinolylmethylidene)-4-methy-2-aminobenzene….

52

Figure 2.10. N-(2-quinolylmethylidene)-4-chloro-2-aminobenzene..

52

Figure 2.11. The variation of the electronic spectra of L¹(in MeOH) titrated with various concentration of Zn(II)chloride at 25ºC in I =0.1 M (NaClO₄)…………………………………………………….

62

Figure 2.12. UV-Vis spectra of the ligand L¹ (1), the synthesized ZnL¹ (2) in MeOH and the end point of the titration of the ligand with Zn ²⁺ (3)……………………………………………………..

62

Figure. 2.13. The variation of the electronic spectra of L⁶(in MeOH ) titrated with various concentration of Cu (II) chloride at 25ºC in I = 0.1 M (NaClO₄)……………………………………………

63

Figure 2.14. Spectrophotometric titration of L⁹ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

64

FIGURES

PAGE

Figure 3.1. The structure of tetraaza complexes……………………………

68

Figure 3.2. The structure of triaza complexes………………………………

69

Figure 3.3. IR spectrum of L²…………………………………………………….

89

Figure 3.4. IR spectrum of NiL²Cl₂…………………………………………….

89

Figure 3.5. IR spectrum of L⁵…………………………………………………….

90

Figure 3.6. IR spectrum of ZnL⁵Cl₂……………………………………………

90

Figure 3.7. Types of electronic transition energy diagram…………….

92

Figure.3.8. Examples of transitions and resulting λ_max…………………..

93

Figure 3.9. The effect of increasing conjugation on the absorption ..

94

Figure 3.10. Proton NMR Chemical Shifts for Common………………

100

Figure 3.11. ¹H-NMR spectrum of L⁸…………………………………………

104

Figure 3.12. ¹H-NMR spectrum of NiL⁸……………………………………..

105

Figure 3.13. Chemical structure of the ligand H₂L for inhibiting the growth………………………………………………………………………….

124

Figure 3.14. Chemical structure of the metal complexes of 7-chloro-4-(o-hydroxybenzilidenehydrazo)quinoline with antimicrobial activities M= Co(II), Fe(II), Ni(II)……………….

125

Figure 3.15. Molecular structures of Schiff base ligands and their copper (II) complexes for catalytically cleavage of DNA…..

126

Figure 3.16. Chemical structure of the isatin- diimine copper (II) complexes…………………………………………………………………….

127

Figure 3.17. Chemical structures of quinoline-2-carboxaldehyde and copper (II) complex…………………………………………………

128

Figure3.18. Chemical structure of LMW-chitosan zinc complex…..

129

Figure 3.19. Chemical structures of ligands with antitumor activities……………………………………………………………………….

130

Figure 3.20. Chemical structures of the Schiff base ligand and its platinum complex………………………………………………………….

130

Figure 3.21. Chemical structure of the Taurine Schiff base ligand and its copper complex…………………………………………………..

131

Figure 3.22. Chemical structure of three Schiff bases (PDH, HHP and PHP) cosidered for cytotoxic and anticancer activities..

132

Figure 3.23. Synthesis of Azomethine derivatives………………………..

132

Figure 3.24. Chemical structure of Schiff base ligand derived from 4-aminoantipyrine, 3-hydroxy-4-nitrobenzaldehyde and o-phenylenediamine………………………………………………………….

133

Figure 3.25. Chemical structure of trimethoprim (2,4-diamino-5-(3`,4`,5`-trimethoxybenzyl) pyrimidine)…………………………..

134

Figure 3.26. Chemical structure of the Cu(TAAB)²⁺ copper complex use as an anticancer agent………………………………….

135

Figure 3.27. Chemical structure of triaza ligand with pyridine moiety………………………………………………………………………….

136

Figure 3.28. Chemical structure of ligand prepared from salicylaldehyde and o-amino benzoic acid………………………..

136

Figure 3.29. Representative chemical structures of macrocyclic Mn(III) complexs………………………………………………………….

137

Figure 3.30. Structure of mono, bis-2,2-(arylidineaminophenyl) benzimidazoles ……………………………………………………….

138

Figure 3.31. Chemical structure of complexes where, M = Co(II), Ni(II), Cu(II), Zn(II) X = Cl^–, NO₃^– , CH₃COO……………………….

139

Figure 3.32. Chemical structure of the Schiff base complex for mercury electrode………………………………………………………….

142

Figure 3.33. Chemical structure of imines (3, 4), salicylaldehyde and ethyleneamine………………………………………………………………..

143

Figure 3.34. Chemical structures N-(2-methylphenyl)salicyaldimine, N-(2-hydroxyphenyl) salicyaldimine, N-(2-methoxyphenyl)- salicyaldimine and N-(2-nitrophenyl)salicyaldimine·HCl…………

145

Figure 3.35. Chemical structure of salen Schiff bases, A1 and A2 with inhibitor properties………………………………………………………………

146

Figure 3.36. Chemical structure of Sensor with selectivity to Zn²⁺…

146

Figure 3.37. Chemical structure of the Schiff bases by enhancing the selectivity………………………………………………………………………

147

Figure 3.38. Chemical structures of two suitable ionophores used in construction of the Cr³⁺ and Cu²⁺selective membrane sensors……

148

Figure 3.39. Chemical Structure of macrocyclic tetraaza as selective electrode……………………………………………………………………….

149

Figure 3.40. Chemical structure of N, N`-bis(2-nitrobenzyl) ethylendiimine L₁ and its complexes as an electrode………….

150

Figure 3.41. IR spectrum of L¹…………………………………………………..

174

Figure 3.42. ¹H-NMR spectrum of L¹…………………………………………

174

Figure 3.43. IR spectrum of NiL¹……………………………………………….

175

Figure 3.44. Spectrophotometric titration of L¹ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

175

Figure 3.45. IR spectrum of ZnL¹……………………………………………….

176

Figure 3.46. ¹H-NMR spectrum of ZnL¹……………………………………..

176

Figure 3.47. Spectrophotometric titration of L¹ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

177

Figure 3.48. Spectrophotometric titration of L¹ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

177

Figure 3.49. Spectrophotometric titration of L¹ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

178

Figure 3.50. IR spectrum of L²…………………………………………………..

178

Figure 3.51. ¹H-NMR spectrum of L²…………………………………………

179

Figure 3.52. IR spectrum of NiL²……………………………………………….

179

Figure 3.53. Spectrophotometric titration of L² with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

180

Figure 3.54. IR spectrum of ZnL²……………………………………………….

180

Figure 3.55. ¹H-NMR spectrum of ZnL²……………………………………..

181

Figure 3.56. Spectrophotometric titration of L² with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

181

Figure 3.57. Spectrophotometric titration of L² with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

182

Figure 3.58. IR spectrum of L³…………………………………………………..

182

Figure 3.59. ¹H-NMR spectrum of L³…………………………………………

183

Figure 3.60. IR spectrum of NiL³……………………………………………….

183

Figure 3.61. Spectrophotometric titration of L³ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

184

Figure 3.62. IR spectrum of ZnL³……………………………………………….

184

Figure 3.63. ¹H-NMR spectrum of ZnL³……………………………………..

185

Figure 3.64. Spectrophotometric titration of L³ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

185

Figure 3.65. IR spectrum of CuL³………………………………………………

186

Figure 3.66. . Spectrophotometric titration of L³ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

186

Figure 3.67. Spectrophotometric titration of L³ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

187

Figure 3.68. IR spectrum of L⁴…………………………………………………..

187

Figure 3.69. ¹H-NMR spectrum of L⁴ ………………………………………..

188

Figure 3.70. IR spectrum of NiL⁴……………………………………………….

188

Figure 3.71. Spectrophotometric titration of L⁴ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

189

Figure 3.72. IR spectrum of ZnL⁴……………………………………………….

189

Figure 3.73. ¹HNMR spectrum of ZnL⁴………………………………………

190

Figure 3.74. Spectrophotometric titration of L⁴ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

190

Figure 3.75. Spectrophotometric titration of L⁴ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

191

Figure 3.76. IR spectrum of CuL⁴………………………………………………

191

Figure 3.77. Spectrophotometric titration of L⁴ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

192

Figure 3.78. IR spectrum of L⁵…………………………………………………..

192

Figure 3.79. ¹H-NMR spectrum of L⁵…………………………………………

193

Figure 3.80. IR spectrum of NiL⁵……………………………………………….

193

Figure 3.81. Spectrophotometric titration of L⁵ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

194

Figure 3.82. IR spectrum of ZnL⁵……………………………………………….

194

Figure 3.83. ¹HNMR spectrum of ZnL⁵………………………………………

195

Figure 3.84 Spectrophotometric titration of L⁵ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

195

Figure 3.85. IR spectrum of CuL⁵………………………………………………

196

Figure 3.86. Spectrophotometric titration of L⁵ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

196

Figure 3.87. IR spectrum of L⁶…………………………………………………..

197

Figure 3.88. ¹H-NMR spectrum of L⁶…………………………………………

197

Figure 3.89. IR spectrum of NiL⁶……………………………………………….

198

Figure 3.90. Spectrophotometric titration of L⁶ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

198

Figure 3.91. IR spectrum of ZnL⁶……………………………………………….

199

Figure 3.92. ¹H-NMR spectrum of ZnL⁶……………………………………..

199

Figure 3.93. Spectrophotometric titration of L⁶ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

200

Figure 3.94. Spectrophotometric titration of L⁶ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

200

Figure 3.95. IR spectrum of CuL⁶………………………………………………

201

Figure 3.96. Spectrophotometric titration of L⁶ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………….

201

Figure 3.97. IR spectrum of L⁷…………………………………………………..

202

Figure 3.98. ¹H-NMR spectrum of L⁷…………………………………………

202

Figure 3.99. IR spectrum of NiL⁷……………………………………………….

203

Figure 3.100. Spectrophotometric titration of L⁷ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

203

Figure 3.101. IR spectrum of ZnL⁷……………………………………………..

204

Figure 3.102. ¹H-NMR spectrum of ZnL⁷……………………………………

204

Figure 3.103. Spectrophotometric titration of L⁷ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

205

Figure 3.104. Spectrophotometric titration of L⁷ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

205

Figure 3.105. IR spectrum of CuL⁷…………………………………………….

206

Figure 3.106. Spectrophotometric titration of L⁷ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

206

Figure 3.107. IR spectrum of L⁸…………………………………………………

207

Figure 3.108. ¹H-NMR spectrum of L⁸……………………………………….

207

Figure 3.109. IR spectrum of NiL⁸……………………………………………..

208

Figure 3.110. ¹H-NMR spectrum of NiL⁸……………………………………

208

Figure 3.111. Spectrophotometric titration of L⁸ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

209

Figure 3.112. Spectrophotometric titration of L⁸ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

209

Figure 3.113. IR spectrum of ZnL⁸……………………………………………..

210

Figure 3.114. ¹H-NMR spectrum of ZnL⁸……………………………………

210

Figure 3.115. Spectrophotometric titration of L⁸ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

211

Figure 3.116. IR spectrum of CuL⁸…………………………………………….

211

Figure 3.117. Spectrophotometric titration of L⁸ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

212

Figure 3.118. IR spectrum of L⁹…………………………………………………

212

Figure 3.119. ¹H-NMR spectrum of L⁹……………………………………….

213

Figure 3.120. Spectrophotometric titration of L⁹ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

213

Figure 3.121. IR spectrum of NiL⁹……………………………………………..

214

Figure 3.122. Spectrophotometric titration of L⁹ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

214

Figure 3.123. IR spectrum of ZnL⁹……………………………………………..

215

Figure 3.124. ¹H-NMR spectrum of ZnL⁹……………………………………

215

Figure 3.125. Spectrophotometric titration of L⁹ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C………………………………………..

216

Figure 3.126. IR spectrum of CuL⁹…………………………………………….

216

Figure 3.127. Spectrophotometric titration of L⁹ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

217

Figure 3.128. IR spectrum of L¹⁰………………………………………………..

217

Figure 3.129. ¹H-NMR spectrum of L¹⁰………………………………………

218

Figure 3.130. Spectrophotometric titration of L¹⁰ with CoCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

218

Figure 3.131. IR spectrum of NiL¹⁰…………………………………………….

219

Figure 3.132. Spectrophotometric titration of L¹⁰ with NiCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

219

Figure 3.133. IR spectrum of ZnL¹⁰……………………………………………

220

Figure 3.134. ¹H-NMR spectrum of ZnL¹⁰…………………………………..

220

Figure 3.135. Spectrophotometric titration of L¹⁰ with ZnCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

221

Figure 3.136. IR spectrum of CuL¹⁰……………………………………………

221

Figure 3.137. Spectrophotometric titration of L¹⁰ with CuCl₂.4H₂O in MeOH at I = 0.1 M at 25 ^ͦ C…………………………………………

222