New Reactions And Moleculer Structures Of Tungsten /molybdenum Complexes Supported By Me₃tacn Ligands

1,4,7-Trimethyl-l,4,7-triazacyclononane?Me₃tacn?is a cyclic amine ligand with both thermodynamic and kinetic stabilities.In past decades,transition metal complexes containing ligand Me₃tacn had been potentially applied in the fields of functional coordination chemistry and bioinorganic chemistry.High-purity ligand Me₃tacn was prepared in a high yield in the lab with new synthetic optimizing route.The new reactions and molecular structures of tungsten/molybdenum complexes supported by the Me₃tacn ligands are reported in the thesis.Treatment of M?CO?₆?M=W,Mo?with Me₃tacn in refluxing mesitylene afforded tungsten?0?/molybdenum?0?complexes?Me₃tacn?M?CO?₃?M=W,1a;Mo,1b?.Interaction of 1a or 1b with iodine in chloroform gave the corresponding oxide products,tungsten?II?/molybdenum?II?complexes[?Me₃tacn?M?CO?₃I]PF₆?M=W,2a;Mo,2b?,respectively.Reaction of 1a or 1b with concentrated hydrochloric acid?37%?in the air atmosphere resulted in the formation of tungsten?V?/molybdenum?V?complexes[?Me₃tacn?MOCl₂]PF₆?M=W,3a;Mo,3b?,respectively.Treatment of 1a or 1b with 30%H₂O₂ aqueous in tetrahydrofuran harvested decarbonation products tungsten?VI?/molybdenum?VI?complexes?Me₃tacn?MO₃·4H₂O?M=W,4a;Mo,4b?.The present eight various valences tungsten/molybdenum complexes?1a⁴a,1b⁴b?with the Me₃tacn ligands were well characterized by NMR,FT-IR and UV-Vis spectroscopies,of which molecular structures of complexes 1a,2a,4a,1b,3b and 4b were unambiguous established by single-crystal X-ray diffraction.Di-valent tungsten?II?/molybdenum?II?complexes 2a and 2b were selectively reacted with dialkyldithiocarbamate ligands,the corresponding seven tungsten?II?/molybdenum?II?complexes[?Me₃tacn?W?CO?₂?S₂CNR₂?]I?R=Me,5a;ⁱPr,7a?and[?Me₃tacn?Mo?CO?₂?S₂CNR₂?]PF₆?R=Me,5b;Et,6b;ⁱPr,7b;ⁿPr,8b;ⁿBu,9b?with bidentate dialkyldithiocarbamate ligands were thus obtained.The isolated seven tungsten?II?/molybdenum?II?-dtc complexes were characterized by NMR,FT-IRand UV-Vis spectrocopies,of which the molecular structures of complexes 5a,7a,5b,7b and 8b were confirmed by single-crystal X-ray diffraction.Structural analysis show that complexes 5a,7a,5b,7b and 8b are all di-valent cationic species,and the bidentate sulfur ligands are delocalized to the center of tungsten/molybdenum to form a seven-coordinate piano-stool structure.Penta-valent tungsten?V?/molybdenum?V?complexes 3a and 3b were selectively reacted with dialkyldithiocarbamate ligands,affording the corresponding six tungsten/molybdenum complexes 12a and 10¹4b with bidentate dialkyldithiocarbamate ligands.The complexes 12a and 10¹4b were characterized by IR and UV-Vis spectroscopies to speculate their possible structures.Reaction of the hexa-valent tungsten or molybdenum complexes 4a or 4b with copper perchlorate at a molar ratio of 4:1 gave the complexes{[?Me₃tacn?MO₃]₄Cu}?ClO₄?₂?M=W,15a;Mo,15b?.[ⁿBu₄N]₂[Mo₆O₁₉]was added to the complexes 15a and 15b dissolved in acetonitrile,respectively,obtaining the large anion-altered complexes{[?Me₃tacn?MO₃]₄Cu}[Mo₆O₁₉]?M=W,16a;Mo,16b?.The complexes 15a,15b,16a and 16b,were characterized by IR and UV-Vis spectroscopies,an indicative of copper-centered tetrahedral complexes bridged through four oxygen atoms of four?Me₃tacn?MO₃?M=W,Mo?moieties as metalloligands.Furthurmore,cyclic voltammetry measurements were performed on zero-valent,divalent,pentavalent,and hexavalent tungsten and molybdenum compounds,respectively,to study their corresponding redox properties.