Synthesis, Characterization And Properties Of New Copolymers Containing Bicycle[2.2.2]oct-7-ene

Transition metal had played an important role in organic synthesis, people had takengood advantage of special catalytic properties of transition metal in order to synthesis novelpolymers. Among them, the transition metal catalyzed alkynes cycloaddition had been widelyused as an effective tool in organic synthesis. Transition metals had region and Stereoselectivity and also could construct complex structures in one step. This paper we hademployed chemo-and stereo selective nickel （0）-Ni（CO）₂（PPh₃）₂as catalyst and developed anefficient method to catalyze terminal diyne and maleimide double-cycloaddition reactionwhich was a new method to afford polymers with rigid fence-like structure.Nickel（0）-catalyzed double-cycloaddition reactions of N-octyl-3,6-diethynylcarbazole,9-（4-octyloxyphenyl）-3,6-diethynylcarbazole, bis（4-ethynylphenyl）-phenylamine,2,5-bis-（4-ethynyl-phenyl）-[1,3,4]oxadiazole,2,7-bis（ethynyl）-fluorenone and3,5-Bis-（4-ethynyl-phenyl）-1-phenyl-4,5-dihydro-1H-pyrazole with N-n-octylmaleimide or N-phenylmaleimideto afford many new comb-like structure polymers were investigated in THF. We mainlyinvestigated the influence of catalyst concentration, and molar ratio of N-Substitutedmaleimides to diyne on terminal diyne and maleimide double-cycloaddition reaction. Theresults suggested that when the catalytic molar concentration is6mmol/l, the yield is thehighes（tup to97.7%）. We also noticed that when the molar ratio of N-substituted maleimidesto diyne was increased from2to2.1, the soluble part of polymer yield could be improved.Structures of double-cycloaddition polymers were identified by IR, NMR and UV-vis,Properties of polymers were examinated by thermal analysis, fluorescence spectrum analysisand cyclic voltammetry.The polymers were soluble in common organic solution （such asCHCl3, THF, CHCl₂et.）, some of them were partly soluble, good yield （up to97.7%）, thehigh molecular weight （up to1.4×10⁴）, good thermostability （temperature for10%weightloss≥368℃, the graphitize in high yield （up to42.2%） when pyrolyzed at900℃）Fluorescence spectrum analysis showed that polymers emit blue, purple, green light in CHCl₂solution. Cyclic voltammetry discovered the HOMO values of polymers were between-8.39and-6.78eV and LOMO values was between-3.21and-4.26eV.