Synthesis And Property Study On Novel NCO Pincer Rare-Earth Metal Complexes With Electron-rich Indolyl Backbone Ligands

The development of high reactivity or high catalytic activity of rare-earth metal organic complexes by ligand modification has always been an important research content of organolanthanide chemistry.In recent years,although different types of pincer metal organic complexes have been synthesized,and significant progress has also been made in their reactivity and application.However,the pincer ligands and their rare-earth metal complexes with electron-rich indolyl backbone have not been reported in the literature.This paper combines the electronic-rich features of indole and the advantages of pincer tridentate ligands,through the systematic study of these ligands and complexes,a new synthesis method of novel pincer rare-earth metal complexes with electron-rich indolyl backbone ligands can be constructed.The thesis focused on the reactivity of the rare-earth metal alkyl compounds RE?CH₂SiMe₃?₃?THF?₂ with 1,3-disubstituted indolyl pincer ligand.The synthesis,coordination chemistry and properties of novel NCO pincer rare-earth metal complexes with electron-rich indolyl backbone ligands were also studied.The ligand1-?2-CH₂C₄H₇O?-3-?2,6-ⁱPr₂C₆H₃N=CH?-C₈H₅N has been synthesized.A series of pincer rare-earth metal dialkyl complexes [?¹:?¹:?¹-1-?2-CH₂C₄H₇O?-3-?2,6-ⁱPr₂C₆H₃N=CH?-C₈H₄N]Y?CH₂SiMe₃?₂?THF??4a?,[?¹:?¹:?¹-1-?2-CH₂C₄H₇O?-3-?2,6-ⁱPr₂C₆H₃N=CH?-C₈H₄N]RE?CH₂SiMe₃?₂?RE=Yb?4b?,Er?4c?,Dy?4d??supported by a functionalized indolyl ligand with the C?sp²?-H activated at the 2-indolyl position were obtained by treatment of RE?CH₂SiMe₃?₃?THF?₂?RE=Yb,Er,Y,Dy?with 1 equiv.of ligand.And a series of mononuclear rare-earth metal complexes[?¹:?¹:?³-1-?2-CH₂C₄H₇O?-3-?2,6-ⁱPr₂C₆H₃NCH?-2-?CH₂SiMe₃?-C₈H₄N]RE[?¹:?¹:?¹-1-?2-CH₂C₄H₇O?-3-?2,6-ⁱPr₂C₆H₃N=CH?-C₈H₄N]?RE=Y?5a?,Er?5b?,Dy?5c?,Gd?5d??supported by two functionalized indolyl ligands were obtained by treatment of RE?CH₂SiMe₃?₃?THF?₂?RE=Er,Y,Dy,Gd?with 2 equiv.of ligands.A hydrocarbyl group?-CH₂SiMe₃?migrates into the the 2-C position of one of the indolyl ligands to change the C?sp²?becomes C?sp³?,a new RE-C?sp³?bond is formed and accompanied by the formation of aza-allyl,the reaction mechanisms were considered by density functional theory?DFT?calculations and it suggests that the formation of the aza-allyl moiety is the intrinsic driving forces for the 1,1-migration of CH₂Si?CH₃?₃.All the complexes were identified by single-crystal X-ray diffraction technique and characterized by nuclear magnetic,infrared and elemental analysis.