Reactivity of some osmium complexes containing a salen ligand

The reactivity of some osmium complexes containing salchda ligands (salchda = N,N’-bis(salicylidene)- o-cyclohexyldiamine) has been investigated. The contents are divided into three main parts. In part I, the reactivity of osmium(VI) nitrido complexes containing salchda ligands towards various nucleophiles such as amines and phosphines have been studied. Several osmium(III), (IV) and (VI) complexes was isolated and characterized with IR, ESI-MS and CHN elemental analysis. Two osmium(VI) nitrido complexes, [NnBu4][OsVI(N)Cl4(im)] and [OsVI(N)Cl3(pz)3], were prepared from [NnBu4][Os(N)Cl4]. The cytotoxity of these two complexes were determined and the IC50 value obtained for [OsVI(N)Cl3(pz)3] is at 37μM which implies the complex is rather cytotoxic. The reaction between [OsVI(N)(salchda)(MeOH)PF6] and bis(phenylphosphino)acetylene afforded a phosphoaminato complex [OsIV(NHP(=O)(Ph)2)(salchda)(OMe)] and its structure has been determined by X-ray crystallography. In part II, several osmium(IV) salchda complexes have been prepared from the reaction between trans-[OsVI(salchda)O2] and hydrazine monohydrate. Various alkoxyl group and arylamines were incorporated onto the osmium center and they were characterized by IR, ESI-MS, UV and CHN analysis…


Chapter 1 Synthesis and Reactivity of Osmium(VI) Nitrido Complexes with various Nucleophiles such as Amines and Phosphines
1.1 Nitrogen Fixation
1.2 Cleavage of N≣N Triple Bonds
1.3 Reactivity of Osmium Nitrido Complexes
1.4 Formation of µ-Dinitrogen Osmium Complexes
1.5 Schiff Base Ligands
1.6 N-heterocyclic Ligands
1.7 Experimental
1.7.1 Materials
1.7.2 SynthesesNnBu4[OsVI(N)Cl4(Im)] (1.1)[OsVI(N)(pz)2Cl3] (1.2)
[OsVI(N)(salchda)N3] (1.3)
[OsIII(salchda)(H2O)N3] (1.4) [Os
IV(NHP(=O)(Ph)2)(salchda)(OMe)] (1.5)
1.8 Results and Discussion
1.8.1 Synthesis and Characterization of Nitridoosmium(VI) Complexes containing Imidazole and Pyrazole
1.8.2 Synthesis and Characterization of (Salchda)osmium Azido Complexes
1.8.3 Synthesis and Characterization of Osmium(IV) Phosphiniminato complex
1.8.4 Preparation of Bimetallic Osmium Nitrido Complexes using a Hexadentate Schiff Base Ligand
Chapter 2 Synthesis and Characterization of Bis(alkoxy)- and Bis(anilido)- osmium(IV) Salchda complexes
2.1 Terminal Metal Oxo Complexes
2.2 Reactivity of Ruthenium Dioxo Complexes towards Amines
2.3 Reactivity of Osmium Dioxo Complexes
2.3.1 Reactivity of Dioxoosmium(VI) Porphyrin Complexes
2.3.2 Reactivity of Dioxosmium (VI) salen complexes
2.3.3 Oxo-bridged Osmium Complexes
2.3.4 Magnetism of Bis(alkoxy) and Bis(anilido)osmium(IV) Complexes
2.4 Experimental
2.4.1 Materials
2.4.2 Syntheses of Osmium(IV) Salchda Complexestrans-[OsVI(salchda)(O)2] (2.1)
IV(salchda)(OMe)2] (2.2)
IV(salchda)(OEt)2] (2.3)
IV(salchda)(O iPr)2] (2.4)
µ-O[OsIV(salchda)Cl]2 (2.5)
trans-[OsIV(salchda)(NHPh)2] (2.6)
IV(salchda)(3,5-Me2PhNH)2] (2.7)
2.5 Results and Discussion
2.5.1 Synthesis and Characterization of Dioxoosmium(VI) Salchda Complexes
2.5.2 Synthesis and Characterization of Bis(alkoxy)osmium(IV) Salchda Complexes
2.5.3 Reactivity of Bis(methoxy)osmium(IV) Salchda Complexes
2.5.4 Formation of Oxo-bridged (salchda)osmium(IV) Complexes
2.5.5 Synthesis and Characterization of Bis(anilido)osmium(IV) Salchda Complexes
Chapter 3 Reaction of Bis(acetonitrile)osmium(III) Salchda Complex with Various Amines
3.1 Introduction
3.1.1 Nitrile as ligands
3.1.2 Substitution Reaction of Coordinated Nitriles
3.1.3 Electrophilic Addition to Nitrile Ligands
3.1.4 Nucleophilic Addition of Nitrile Ligands
3.1.5 Osmium Complexes with Coordinated Acetonitrile
3.2 Experimental
3.2.1 Materials
3.2.2 Synthesestrans-[OsIII(salchda)(CH3CN)2]PF6 (3.1)trans-{OsIII
(salchda)[NH=C(CH3)(NHC4H9)]2}PF6 (3.2)trans-{OsIII
(salchda)[NH=C(CH3)(NHC2H4NH2)]2}PF6 (3.3)trans-{OsIII
(salchda)[NH=C(CH3)(NHC6H11)]2}PF6 (3.4)trans-{OsIII
(salchda)[NH=C(CH3)(NHC7H7)]2}PF6 (3.5)trans-{OsIII
(salchda)[NH=C(CH3)(NC4H10)]2}PF6 (3.6)trans-{OsIII
(salchda)[NH=C(CH3)(NC4H8O)]2}PF6 (3.7)trans-{OsIII
(salchda)(CH3CN)[NH=C(CH3)(NH2)]}PF6 (3.8)trans-{OsIII
(salchda)[NH=C(CH3)(NH2)][NH=C(CH3)(NHC4H9)]}PF6 (3.9) trans-{OsIII
(salchda)[NH=C(CH3)(NH2)][NH=C(CH3)(NHC6H11)]}PF6 (3.10)trans-{OsIII
(salchda)[NH=C(CH3)(NH2)][NH=C(CH3)(NC4H8O)]}PF6 (3.11)trans-{OsIII
(salchda)[NH=C(CH3)(NH2)][NH=C(CH3)(NC4H10O2)]}PF6 (3.12) trans-{OsIII
(Salchda) [NH=C(CH3)(NH2)][NH=C(CH3)(NC4H8NH2)]}PF6 (3.13)
trans-{OsIII(salchda)[NH=C(CH3)(NH2)][NH=C(CH3)(OCH3)]}PF6 (3.14)
3.3 Results and Discussion
3.3.1 Synthesis of Bis(acetonitrile)osmium(III) Salchda Complexes
3.3.2 Nucleophilic Addition of trans-[OsIII(salchda)(CH3CN)2]PF6 (3.1) in the Formation of Symmetric Bis(acetamidine)osmium(III) Salchda Complexes
3.3.3 Nucleophilic Addition of Amines to trans-{OsIII(salchda)(CH3CN) [NH=C(CH3)(NH2)]}PF6 (3.8) . Formation of asymmetric Bis(acetamidine)- osmium(III) Salchda Complexes
3.3.4 Base Catalyzed Nucleophilic Addition of Methanol to trans-{OsIII(salchda) [NH=C(CH3)(NH2)](CH3CN)}PF6 (3.8)
3.3.5 UV-Vis Spectra and Cyclic Voltamagrams of Osmium(III) complexes
Chapter 4 Conclusion and suggestion for further work

Author: Ho, Man

Source: City University of Hong Kong

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