Synthesis of Poly(arylene vinylene)s with Different End Groups by Combining Acyclic Diene Metathesis Polymerization with Wittig‐type Couplings

Abstract

As eries of end-functionalized poly(9,9'-di-n-octylfluorene vinylene)s (EF-PFVs) with different end groups were obtained by 1) synthesizing EF-PFV with vinyl end groups by acyclic diene metathesis (ADMET) polymerization with am olybdenum catalyst and termination with an aldehyde and 2) subsequent olefin metathesis of the vinyl group with the molybdenum catalyst followed by Wittig-type coupling with another aldehyde.T he exclusive formation of EF-PFVs containing av inyl end group by the ADMET polymerization was confirmed by grafting PEG,a nd by the synthesis of amphiphilic triblock copolymers by combining atom transfer radical polymerization from the PFV chain end with PEG grafting through ac lick reaction. Various EF-PFVs with different end groups,s uch as C 6 F 5 ,p yridyl, ferrocenyl, and terthiophene,h ave thus been prepared. Their fluorescence spectra (e.g., intensities,emission wavelengths) were influenced by the end groups and the length of the conjugation.Conjugated polymers,s uch as poly(para-phenylene), polyfluorene,p oly(para-arylene vinylene)s,a nd polythiophene, are promising organic materials applied in optoelectronic and electrochemical devices. [1,2] Theprecise,efficient synthesis of defect-free (regular structures,c hemically pure) end-functionalized conjugated polymers has attracted considerable attention, not only for improving device performance, [2] but also because of the unique (optical and/or electronic) properties that result from the end modification (e.g., by energy transfer), as recently demonstrated for polyfluorenes containing discrete end groups,s uch as triarylamines,p erylene monoimide dyes,o rh eteroaryl moieties, [3][4][5] and poly(9,9dialkylfluorene-2,7-vinylene)s (PFVs). [6,7] It has been demonstrated that syntheses by acyclic diene metathesis (ADMET) polymerization [6][7][8][9][10][11] afford defect-free (without halogen/sulfur impurities,r egio-or stereoirregularity,orcross-linking etc.)PFVs, [6][7][8] poly(2,5-dialkylphenylene-1,4-vinylene)s, [9] and poly(N-alkylcarbazole-2,7-vinylene)s [8b] that display better properties than those prepared by conventional condensation (e.g., dehalogenation-condensation, Gilch reaction) methods.M oreover,e xclusive end functionalization can be achieved by treating the vinyl end groups in the resultant polymers prepared with ar uthenium carbene catalyst [6, 8b, 9] with Mo(CHCMe 2 Ph)(N-2,6-Me 2 C 6 H 3 )[OC-(CH 3 )(CF 3 ) 2 ]( "Mo catalyst") followed by Wittig-type coupling with an aldehyde. [12,13] One-pot approaches for combined ADMET polymerization and subsequent end functionalization with Ru [7a] and Mo [7b] catalysts have also recently been established. These methods,h owever,o nly provide synthetic means to introduce the same functional groups at the PFV chain ends,and precise methods for the synthesis of well-defined poly(arylene vinylene)s containing different end groups have been limited thus far.W eh erein report that different end groups can be introduced at PFV chain ends by combining ADMET polymerization with the Mo catalys...

Poly(arylene vinylene) Synthesis via a Precursor Step-Growth Polymerization Route Involving the Ramberg–Bäcklund Reaction as a Key Post-Chemical Modification Step

“…44 After treating the PF-SO under modified Ramberg-Bäcklund reaction conditions, 1 H NMR of PFV revealed a (E)stereoselectivity for the double bonds, a result consistent with observations made for model dibenzylic sulfones reported earlier, 43,45 and that is in good agreement with spectroscopic data reported by Nomura et al concerning PFV synthesis by ADMET. 32,33 It is also worth mentioning that we did not observe any residual benzylic protons at δ 4.20 ppm, attesting to the complete conversion of dibenzylic sulfones into olefinic moieties, and to the formation of fully -conjugated polymers. Average molecular weights were evaluated by size exclusion chromatography (SEC) in THF using polystyrene standards.…”

“…27−31 As an example of the potentiality of these arylene−vinylene polymers, recently, Nomura and colleagues have obtained PPVs with different end-groups by combining acyclic diene metathesis polymerization with Wittig-type couplings. 32,33 Here we describe the synthetic developments validating both strategies, by reporting the synthesis of poly(fluorene vinylene)-and poly(fluorene-carbazole vinylene)-type conjugated (co)polymers.…”

Synthesis of Biobased Long-Chain Polyesters by Acyclic Diene Metathesis Polymerization and Tandem Hydrogenation and Depolymerization with Ethylene

“…We recently reported the synthesis of a new biobased polyester by ADMET polymerization of the monomer (α,ω-diene) derived from castor oil and eugenol (obtained from clove oil). 33 Because we also reported the synthesis of conjugated polymers by ADMET polymerization including the end modification and grafting, 47 , 56 , 57 we thus have an interest in the synthesis of biobased polyesters by AMDET polymerization and subsequent (tandem) hydrogenation and in the degradation of the polymers in the presence of ethylene (to confirm the equilibrium in this system). In this paper, we wish to demonstrate a method for the synthesis of biobased saturated polyesters by tandem ADMET polymerization and subsequent hydrogenation without isolation of unsaturated polymers ( Scheme 2 , HPE1-4), and we also demonstrate the subsequent reaction (depolymerization) with ethylene after the ADMET polymerization.…”

“…The mixture was then placed into a liquid nitrogen bath to remove the ethylene gas from the reaction by opening the valve connected to the vacuum line for a short period (1 min), and the valve was then closed and the tube was placed into the oil bath to continue the reaction. 32 , 57 , 58 The procedure removing ethylene was repeated for a certain period (30 min for the first time then every 1.0 h until 6 h). The polymerization mixture was then cooled to room temperature and was quenched with excess ethyl vinyl ether (two drops, ca.…”

Gold embedded chitosan nanoparticles with cell membrane mimetic polymer coating for pH-sensitive controlled drug release and cellular fluorescence imaging

“…The characteristic 1 H NMR signals of the PMPC chain (-N(C H 3 ) 3 signals at 3.3 ppm, -POCH 2 C H 2 N signals at 3.8 ppm, -POC H 2 CH 2 N, -COOC H 2 C H 2 OP signals at 4.0–4.4 ppm) and BiB-CHO group (-C H O signals at 10.0 ppm, phenyl signals at 7.3–8.2 ppm) were both clearly observed. 28 , 29 GPC result indicated the M n of PMPC was 6.0 kg/mol and had a low polydispersity (M w /M n = 1.17).…”