Synthesis And Characterization Of Thiolate-bridged Diruthenium And Iron-ruthenium Complexes With Isocyanide Ligands

In this thesis,we employed bdt-bridged iron-ruthenium and diruthenium complexes as reaction platform,investigating their coordination activation reactivity toward isocyanides,which provided foundational theoretical guideline for further research on the conversion of isocyanides catalyzed by di-or multinuclear metal complexes.Firstly,we studied the reactivity of bdt-bridged iron-ruthenium heterodinuclear precursor[Cp*Fe??-?²:?⁴-bdt?RuCp*][PF₆]?1[PF₆],Cp*=?⁵-C₅Me₅,bdt=benzene-1,2-dithiolate?toward isocyanides.Whether the substituent is fatty chain or aromatic ring,the isocyanides were all terminally bonded to the iron centre when interacted with complex 1[PF6],resulting in a series of novel thiolate-bridged iron-ruthenium complexes[Cp*Fe?t-RNC???-?²:?⁶-bdt?RuCp*][PF₆]?2a[PF6],R=^tBu;2b,R=ⁿBu;2c,R=2,6-dimethylphenyl?.X-ray diffraction analysis revealed that the coordination mode of bdt changes from?-?²:?⁴ to a rare?-?²:?⁶ mode,and the ruthenium centre forms a stable sandwich structure.Secondly,we explored the reactivity of bdt-bridged iron-ruthenium heterodinuclear complex with terminal hydride ligand[Cp*Fe?t-H???-?²:?⁴-bdt?RuCp*][BF₄]?3?toward ^tBuNC.With the gradual increase of the reaction temperature,the Fe^III-H homolytic cleavage led to release 1/2 molecules of hydrogen and the formation of active Fe^II centre.Spectroscopic and crystallographic studies indicated that the bdt ligand does not remain the?-?²:?⁴ mode as found that in the diiron hydride complex after the coordination of isocyanide,but further tilts toward the ruthenium centre to give an asymmetric structure in a rare?-?²:?⁶ coordination mode.Finally,we investigated the reactivity of bdt-bridged diruthenium complex with a bridging hydride ligand[Cp*Ru??-H???-?²:?⁴-bdt?RuCp*][BF₄]?4?toward ^tBuNC.When complex 4 was treated with 6 equivalents of ^tBuNC,the diruthenium complex containing six isocyanides[?t-^tBuNC?₄Ru??-?²:?¹-bdt?Ru?t-^tBuNC?₂Cp*][BF₄]?5?was obtained with high selectivity.In situ ¹H NMR spectra demonstrated that the bridging hydride and one Cp*ligand are reductive eliminated to generate Cp*H,meanwhile,Ru^IIIRu^III is reduced to Ru^IIRu^II.Further crystallographic studies showed that all of the six ^tBuNC are terminally bonded to ruthenium centres,while the bdt ligand is bridged between the two ruthenium centres in?-?²:?¹ fashion.