The effect of 4-acyl substituents on the infrared stretching frequencies of some 1-phenyl -3- methyl -4- acylpyrazol -5-ones and their magnesium (ii) ,cobalt(ii), copper (ii) and zinc (ii) chelates

• Title page …………………………………………………………………………….. ii Certification …………………………………………………………………….. iii Acknowledgement ……………………………………………………………….. iv Dedication …………………………………………………………………. v Abstract ……………………………………………………………………… vi List of figures ……………………………………………………………… xi List of tables ……………………………………………………………………. xiii Abbreviations ………………………………………………………………… xiv

Chapter ONE

INTRODUCTION

• 1.0Introduction ……………………………………………………… 1

Chapter TWO

LITERATURE REVIEW

• 2.0Literature review ……………………………………………………………… 4
• 2.10Concept of Chelation ………………………………………………………….. 4
• 2.11Metal chelate complexes …………………………………………………………. 5
• 2.12Ion –pair complexes …………………………………………………………….. 5
• 2.13Additive complexes ……………………………………………………………….. 5 8
• 2.20Chelation with β-diketones ……………………………………………………… 6
• 2.30Chelation with 4-acylpyrazolones ………………………………………………… 8
• 2.40Stability of metal chelates ……………………………………………………. 10
• 2.41Nature of the chelating agent …………………………………………………..10
• 2.42The size of the chelate ring ……………………………………………… 11
• 2.43The nature of the central metal …………………………………………….. 11
• 2.44The nature of the metal-ligand bond ……………………………………….. 11
• 2.50Previous work done with β-diketones …………………………………… 12
• 2.51Physical properties and structure elucidation ……………………………… 13
• 2.52Isolation and spectroscopic studies …………………………………………. 15
• 2.60Previous work on metal chelates of β-diketones ………………………………..17
• 2.61The chemistry of magnesium ……………………………………………………17
• 2.62Review of previous work done on magnesium chelates of β-diketones ………..19
• 2.70Chemistry of cobalt ………………………………………………………19
• 2.71Review of previous work done on cobalt chelates of β-diketones …………….23
• 2.80The chemistry of copper ………………………………………………………..24
• 2.81Previous work done on copper chelates of β-diketones …………………………26
• 2.90The chemistry of zinc …………………………………………………………… 28
• 2.91Previous work done on zinc chelates of β-diketones ………………………………29 9
• 2.92Spectroscopic techniques used in the study of ligands and metal complexes …… 30
• 2.93Ultraviolet spectroscopy ……………………………………………………… 30
• 2.94Infrared spectroscopy ………………………………………………………… 31

Chapter THREE

RESEARCH METHODOLOGY

• 3.0Experimental …………………………………………………………. 33
• 3.1Laboratory apparatus and equipments ……………………………………….. 33
• 3.2Laboratory reagents ……………………………………………………………. 33
• 3.3Synthesis of 1-phenyl-3-methyl-4-acylpyrazol-5-ones …………………………35
• 3.31Synthesis of 1-phenyl-3-methyl-4-acetylpyrazol-5-ones (HPMAP) …………… 35
• 3.32Synthesis of 1-phenyl-3-methyl-4-benzoylpyrazol-5-ones (HPMBP) …………… 35
• 3.33Synthesis of 1-phenyl-3-methyl-4-propionylpyrazol-5-ones (HPMPRP) ……… 36
• 3.34Synthesis of 1-phenyl-3-methyl-4-butyrylpyrazol-5-ones (HPMBUP) ………… 36
• 3.35Synthesis of 1-phenyl-3-methyl-4-hexanoylpyrazol-5-ones (HPMCP) …………. 36
• 3.36Synthesis of 1-phenyl-3-methyl-4-palmitoylpyrazol-5-ones (HPMPP) ………… 36
• 3.40Synthesis of 1-phenyl-3-methyl-4-acyllpyrazolonates …………………… 36
• 3.41Synthesis of 1-phenyl-3-methyl-4-acetyl-5-pyrazolonato magnesium II complex 36
• 3.42Synthesis of 1-phenyl-3-methyl-4-acetyl-5-pyrazolonato copper II complex ……37
• 3.43Synthesis of 1-phenyl-3-methyl-4-acetyl-5-pyrazolonato cobalt II complex …… 38
• 3.44Synthesis of 1-phenyl-3-methyl-4-acetyl-5-pyrazolonato zinc II complex …… 39 10
• 3.45Preparation of 3M hydrochloric acid solution ……………………………………39
• 3.50Physical and spectroscopic analysis …………………………………………… 42
• 3.51Melting point determination …………………………………………….. 42
• 3.52Conductivity measurement ……………………………………………. 42
• 3.53Electronic spectra measurement ……………………………………………… 42
• 3.54Infrared spectra measurement …………………………………………… 42

Chapter FOUR

DATA PRESENTATION AND ANALYSIS

• 4.0Results and Discussion …………………………………………………. 43
• 4.10Structure of ligands and complexes ……………………………………… 43
• 4.20Physical data ………………………………………………………………….. 45
• 4.30Conductivity Measurement ………………………………………………… 48
• 4.40Solubility survey of ligands and complexes ………………………………… 49
• 4.50Electronic spectra of ligands and complexes ………………………………….. 51
• 4.60Infrared spectra of ligands and complexes …………………………………… 53
• 4.70The effect of 4-acyl substituents on the infrared carbonyl stretching frequency of metal(II) chelates of some 1-phenyl-3-methyl 4-acylpyrazolone ………………………64
• 4.80Conclusion ……………………………………………………………… 69 References ……………………………………………………………….. 71 Appendices ……………………………………………………………………………… 86