Studies On Anionic Polymerization Of Fluorine-Containing Methacrylates And Synthesis And Characterization Of Germylenes And Stannylenes

In this thesis,a series of fluoroarylmethacrylate monomers were synthesized and utilized to prepare the fluorine-containing functionalized polymers by means of anionic polymerization.The polymers obtained were characterized.The thesis also studied the synthesis and structural characterization of germylene and stannylene compounds bearing several kinds of organic ligands.There generally consists of four sections shown as follows.(Ⅰ)Synthesis and characterization of poly(fluoroarylmethacrylate)Reactions of methacryloyl chloride with five different fluorinated phenols yielded 3-fluoroarylmethacrylate(M1),2,4-difluoroarylmethacrylate(M2),2,3,4-trifluoroarylmethacrylate(M3),2,3,5,6-tetrafluoroarylmethacrylate(M4),pentafluoroarylmethacrylate(M5).Polymerization of Ml and M2 was carried out by using a combined catalyst system that contains a KH,LiAlH4,or tBuLi as main catalyst and MeAl(BHT)2 as a cocatalyst.The KH-containing catalyst system is more efficient than the LiAIH4-mediated catalyst system.The polymers obtained were characterzed to be highly syndiotactic by 1H and 19F NMR spectral analysis.(Ⅱ)Synthesis and characterization of cyclopentadienyl,indenyl and fluorenyl stannylenes and germylenes bearing β-diketiminato ligandβ-Diketiminato ligand-stabilized tin(Ⅱ)or Ge(Ⅱ)cyclopentadienyl,indenyl and fluorenyl complexes L1M(Ⅱ)R(L1 = HC[CMe(N-2,6-iPr2C6H3)]2,M = Sn,R = C5H5(1),C9H7(2),C13H9(3);M = Ge,R = C9H7(4),C13H9(5))were prepared and characterized.X-ray crystallographic studies revealed novel Sn-η1-C5H5,Sn-η1-C9H7,Sn-η1-C13H9,Ge-η1-C9H7 and Ge-η1-C13H9 bond modes in the respective compounds 1-4 that were caused due to both the electronic by the tin(Ⅱ)lone pair and the steric effect from the L ligand.Although the crystals of compound 5 were not obtained,it may adopt a structure similar to that of compound 3 on the basis of the NMR data.Room and variable-temperature(-75～25 ℃)1H NMR studies of compounds 1-3 disclosed an averaged dynamic behavior of these bonds in solution irrespective of the electronic influence by the tin(II)lone pair.However,low temperature 1H NMR studies detected a unique solution behavior of the L1 N-aryl substituents affected by an asymmetric environment that was induced due to the R group and the lone pair at the Sn atom.And in turn,the solution behavior of the R groups especially the C13H9 group was also affected by an asymmetric environment that was induced due to the L1 N-aryl substituents and the lone pair at the Sn atom.(Ⅲ)Synthesis,characterization,and reactivity exploration of stannylenes and germylenes stabilized by NP-,NSi-ligandsReactions of L2Li(L2 = 2,6-iPr2C6H3N(PPh2),L3Li(L3 = 2,4,6-Me3C6H2N(PPh2))and L4Li(L4 =tBuN(PPh2))with SnCl2 were carried out,and stannylene compounds([L2SnCl]2(6),[L3SnCl]2(7),[L4SnCl]2(8),L22Sn(10),and L32Sn(11)were isolated respectively.Compounds 6 and 11 were characterized by single-crystal X-ray structural analysis.Compound 6 is a dimer and contains a distorted N2P2Sn2 six-membered ring.In addition,compounds L42Sn2OSnCl2(9)and(L5Li)2(L5=2,4,6-Me3C6H2N(SiMe2Ph))(12)were also obtained and characterized.The oxidative reaction of compound 11 with selenium powder to give L32SnSe2(13)was accomplished.(IV)Synthesis and characterization of stannylenes and germylenes stabilized by salicyladiminato ligand(L6)L6GeCl(14)was successfully prepared from reaction of GeCl2·dioxane with L6Li in a molar of 1:1.Compound 14 was characterized by elemental analysis,NMR spectroscopy,and single-crystal X-ray structural determination.