| Titre : | Experimental and theoretical Study of complexation properties of metals with bidentate ligands |
| Auteurs : | Mokaddem Ismail, Auteur ; Houari brahim, Directeur de thèse |
| Type de document : | texte manuscrit |
| Editeur : | Université MOULAY Tahar,Saida Faculté des Sciences Département de Chimie, 2018/2019 |
| Format : | 86 ص |
| Accompagnement : | CD |
| Note générale : |
In the last decade, transition metal complexes with quinazolione ligands have attracted much
attention and have been studied extensively in both experimental and theoretical areas1.2. The quinazoline ring system along with many alkaloids is widely recognized in inorganic syntheses and medicinal applications, for example, in HIV reverse transcriptase inhibitors. Some of them or their metal are used as biological models in understanding of biomolecules and biological processes. Such compounds have become the center of creating new drugs, some with highly active compounds have been commercialized such as fungicide fuquinconazole, anti-cancer drug, antihypertensive pyrazosin, etc. Some transition metal complexes with quinazoline analogs have been investigated in coordination chemistry and biological chemistry, although much remains to be understood. Nickel(II) complexes with oxime-type ligands have been widely investigated in coordination and biological chemistry, but cleavage of tow C-N bonds of shiff bases have not been observed in reaction with metal salts, and there is more interest about complexes in general, this is due to their rich applications in many fields: as catalyst supports 3.4, in the fields of organic lightemitting diodes OLED 5.6, as antimicrobial agents in biological activities 7, and as candidates for anticancer agents 8.9. LAN-QIN CHAI and coworkers, have been synthesized an unexpected mononuclear Ni(II) complex[Ni(L2)2]-CH3OH(HL2=1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino} phenyl)ethanoneoxime) via complexation of Ni(II) acetate tetrahydrate with HL1. HL1 and its corresponding Ni(II) complex were characterized byIR, 1H-NMR spectra, HRMS, as well as by elemental analysis, UV–vis, and emission spectroscopy.The crystal structure of the complex has been determined by single-crystal X-ray diffraction. Eachcomplex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonds.Moreover, the electrochemical properties of the nickel complex were studied by cyclic II voltammetry.Superoxide dismutase-like activities of HL1 and Ni(II) complex were also investigated.10 In the present work (theoretical), we studied theoretically the geometric structures, frontier molecular orbital (FMO) character, energy gaps and UV spectra of [Ni(L2)2] by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The theoretical results are compared with experimental data. Also regarding to the experimental work, this part includes, the synthesis of a Schiff base ligand, N, N’-ethylenebis( 2-benzoylpyridine imine) denoted as LB and their corresponding metalcomplexes like Cu(II) and Co(II) and they were characterized by 1H NMR, 13C NMR (LB) and IR (Cu(II)), (Co(II)). |
| Langues: | Anglais |
| Index. décimale : | BUC-M 008279 |
| Catégories : | |
| Mots-clés: | Ligands, Nickel (II), Cobalt (II), Copper (II), Metal complex, Infrared, Uv-visible, DFT, TDDFT, NMR. Ligands, Nickel (II), Cobalt (II), Copper (II), complexe, Infrarouge, Uv-visible, DFT, TDDFT, RMN. |
| Résumé : |
In this work, the structures, Frontier molecular orbitals, UV-visible and IR absorption spectra
of the complexes [Ni(L)2] have been computed by means DFT and TD-DFT methods. Also we have been synthesized a Schiff base ligand and two complexes Cu(II); Co(II) and we characterized them using IR and NMR (1H, 13C). Dans ce travail, les structures, les orbitales moléculaires frontier, les spectres d'absorption UV- visible et IR des complexes [Ni(L)2] ont été calculées à l'aide des méthodes DFT et TD-DFT. Nous avons aussi synthétisé un ligand d’une base de Schiff et deux complexes Cu (II); Co(II) et nous les avons caractérisées par IR et RMN (1H, 13C). في هذا العمل، قمنا بدراسة بنية المعقد السابق، المدارات الجزيئية الحدوديةوأطياف االمتصاصالبنفسجية-المرئية وتحت الحمراء للمعقد]2[Ni(L)باستعمال النظرية الوظيفية للكثافةوالنظرية الوظيفيةللكثافة المتعلقة بالزمن. كذلك قمنا بتصنيع رُبيطةSchiff baseومعقدينCu(II)وCo(II)وقمنا بتحليلهما بواسطةIRوC)13 H,1 NMR (. |
| Note de contenu : |
Introduction I
Chapter I I. COORDINATION COMPOUNDS AND SPECTROSCOPY I.1 Coordination Compounds …………………………………………………………... 1 I.1.1 Transition Elements …………………………………………………………....... 1 I.1.1.a Definition and proprieties …………………………………………………. 1 I.1.2 Ligands ……………………………………………………………................................ 2 I.1.3 The Covalent Bond Classification Method …………………………………....... 2 I.1.3.a L ligands ……………………………………………………………..................... 2 I.1.3.b X ligands …………………………………………………………….................... 3 I.1.4 Other Types of ligands: ………………………………………………………………. 4 I.1.4.a Monodentate ligand ……………………………………………………….. 4 I.1.4.b Bidentate ligand …………………………………………………………… 4 I.1.4.c Polydentate ligand ………………………………………………………… 4 I.2 Schiff base ……………………………………………………………....................... 4 I.3 Structures of Metal Complexes …………………………………................................ 4 I.3.1 Coordination Numbers …………………………………....................................... 5 I.3.1.a Coordination Number 4 …………………………………............................ 5 I.3.1.b Coordination Number 6 …………………………………............................ 5 I.3.1.c Octahedral complexes ………………………………….............................. 6 I.4 Oxidation Number ………………………………………………............................... 6 I.5 Electronic Structure …………………………………………..................................... 6 I.6 Crystal Field Theory ………………………………………………………………… 7 I.7 Ligand Field Theory ……………………………………………………………........ 7 I.8 Molecular Orbitals ………………………………………………………………....... 7 I.8.1 Formation of molecular orbitals ………………………………………………… 8 I.8.2 Molecular orbital theory ……………………………………………………….... 8 I.9 The classification of bonds …………………………………...................................... 9 I.9.1 Ionic Bonds …………………………………....................................................... 9 I.9.2 Covalent Bonds ………………………………..................................................... 9 I.II SPECTROSCOPY 11 I.II.1 Absorption spectroscopy …………………………………..................................... 12 I.II.2 Ultraviolet–visible spectroscopy …………………………………......................... 12 I.II.2.1 Measuring a spectrum …………………………………..................................... 12 I.II.2.2 The Absorption Process ………………………………….................................. 14 I.II.3 Selection rules and intensities ………………………………….............................. 14 I.II.4 Spin selection rules ……………………………………………………………….. 15 I.II.5 Types of molecular transitions …………………………………............................ 16 I.II.5.a σ→σ* Transitions ……………………………………………………………… 16 I.II.5.b n→σ* Transitions ………………………………………………………… 16 ????. ????????. 5. ???? ????→ ????*Transitions ……………………………………………………........ 16 ????. ????????. 5. ???? ????→ ????* Transitions ………………………………………………………………………………… 16 I.II.5.e d→d Transitions ……………………………………………………………. 17 I.II.6 Charge-transfer transitions ……………………………………………………….. 17 I.II.6.a LMCT Transitions ………………………………………………………….. 18 I.II.6.b MLCT Transitions …………………………………………………………. 18 I.II.7 Infrared spectroscopy …………………………………………………………….. 18 I.II.7.1 The techniques …………………………………………………………… 18 I.II.8 Nuclear magnetic resonance ……………………………………………………… 19 Chapter II METHODOLOGY II. Computational methods …………………………………………. 21 II.1 The Schrödinger Equation …………………………………………………………. 22 II.2 Density Functional Methods (DFT) ………………………………………………... 25 II.2.1 Kohn–Sham Theory ……………………………………………………………. 26 II.3 Functionals ……………………………………………………………………….. 29 II.4 Hartree-Fock self-consistent field method …………………………………………. 30 II.5 Time-Dependent Density-Functional Theory (TDDFT) …………………………... 31 II.5.1 Concluding remarks ……………………………………………………………. 35 II.6 Oscillator strength ………………………………………………………………….. 36 II.7 The Gaussian Distribution …………………………………………………………. 37 II.8 Basis Set ……………………………………………………………………………. 38 II.8.1 Pople basis sets ………………………………………………………………………… 38 II.8.2 Correlation-consistent basis sets ………………………………………………….... 39 II.8.3 6–31G* …………………………………………………………………….................... 39 II.I EXPERIMENTAL METHODS AND TECHNIQUES ………………………... 41 II.I.1 Materials and solvents employed ………………………………………………… 42 II.I.2 Experimental methods ……………………………………………………………. 42 II.I.2.a Preparation of Ligand ………………………………………………………… 42 II.I.2.b Preparation of the complexes ………………………………………………… 43 II.I.2.b.1 Synthesis of Copper (II) Complexe ………………………………………. 43 II.I.2.b.2 Synthesis of Cobalt (II) Complexe ……………………………………….. 44 Chapter III Results and Discussion Introduction III. Theoretical results ………………………………………………………….. 47 III.1 Study of geometrical structures …………………………………………………… 48 III.1.1 In DMF Solvent ……………………………………………………………… 48 III.1.2 In DCM Solvent ……………………………………………………………… 48 III.2 Frontier molecular orbitals ……………………………………………………… 50 III.3 Electronic absorption spectra ……………………………………………………… 56 III.3.1 With the dichloromethane (DCM) …………………………………………… 56 III.3.2 With the DMF ……………………………………………………………… 57 III.3.3 Comparative analysis ………………………………………………………… 58 III.I Experimental results ……………………………………………………… 59 III.I.1 Characterization of ligand LB …………………………………………………. 60 III.I.1.1 NMR spectra ……………………………………………………………... 60 III.I.2 Characterization of (Cu(II)) and (Co(II)) complexes ………………………….. 61 III.I.2.1 Infrared spectra …………………………………………………………… 61 Conclusion 63 Refrences |
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