ACTA POL YMERICA SINICA

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1 ACTA POL YMERICA SINICA No. 10 Oct., 2009 { ( + )2 22,52 [ 4 2( ( S)222 ) ] } 3 33 ( ) ( + )2 22,52 [4 2( ( S)222 ) ],. 30,Cotton,.,.,,,,.,,,,, [1 3 ].,, [3 7 ].,, [3 ].,,.,,.,.,. Okamoto [8 ]., mm 98 %., [3 ].,.,Percec,,, [9,10 ]., { ( + )22, 52 [ 4 2( ( S )222 ) ] } (MBPS) [11 ].,,., ( + )2 22,52 [4 2( ( S)222 ) ], (AR, ), (AR, ), N2 (NBS, 99 %, Aldrich), N, N, N, N, N 2 ( PMDETA, 99 %, Aldrich ), ( 99 %, , ; ( ) ( ) ( ) ; 33,E2mail edu. cn 1050

2 10 : { ( + )2 22,52 [4 2( ( S)222 ) ] } 1051 Aldrich),22 (99 %,Aldrich), (AR,, ), (AR, ), (AR, ). (AR, ) CaH 2. (BPO, CP, ), ; 2, 2 (AIBN,CP). (AR, ) (AR, ). ( THF,AR, ) CaH 2,,. ( + )22,52 [ 4 2 ( ( S)222 ) ] [12 ] H2NMR Bruker ARX400 (400 MHz), CDCl 3, TMS. Finnigan2MAT ZAB2HS. Elemental Vario EL. ( GPC), Waters 515 Waters Styragel HT2 + HT3 + TH4,Waters 2410., 35, THF 110 mlπmin. Jasco Model P , 1 dm, THF. 2 Varian Cary2300, THF, molπl. Jasco J2 810, 1 cm,thf, molπl g (30 mmol) KOH 20 ml, 2158 g ( 30 mmol) g(30 mmol) AgNO 3 40 ml. KOH. 10 min,.,, 24 h 3170 g, 6412 % ( + )22,52 [ 4 2( ( S )222 ) ] (BPBMA) 6125 g(15 mmol) ( + )22,52 [ 4 2( ( S)222 ) ], 2167 g(15 mmol) NBS 0112 g BPO 200 ml 3 h.,. 25 ml, (3167 g,19 mmol), 75 ml, 50,.,, ( 1Π1 Π ), Π, 4182 g, 6413 %. 1 H2NMR ( CDCl 3, 400 MHz, ) : (,6H, ), (,6H, ), (,2H, ), (,2H, ), (, 2H, ), 1195 (, 3H, ), (,2H, ), (, 2H, ),5118 (,2H, ), (, 1H, ), 6112 (, 1H, ), (,4H, ), (,3H, ), (,3H, ), ( d,1h, ). ( C 33 H 40 O 4 ), : C 79120, H 8100 ; : C ; H8102. ( mπe) :500 (, ),430, 360,274,181,69. [ ] = ( c = 012 gπdl,thf) g (0148 mmol), 41 L 10 mgπml AIBN, 1 ml. 3,. 60, 24 h., 20 ml THF, 200 ml., 0122 g, 91 % (ATRP) 0150 g (110 mmol) 219 mg 98 L 40 mgπml L 40 mgπml PMDETA 0150 g. 3,. 90,. THF, 200

3 , ml 0115 g(013 mmol) 510 g KOH 20 ml THF 20 ml 40 ml, 72 h,,, THF, ( TLC), 5 % 24 h, h, 5 ml. 5 ml 0114 g, 30 min.., g, 83 % BPBMA 1.,,. NBS..,. Fig. 1 Synthesis of monomer BPBMA,. 2 1 H2NMR. 5, = ; = c f ; = 119., = ; 2 = 210. = 511., k k, = , = j l., = , e, = , = ;, ( [ ] ) 5915, PBPBMA 25 ( 1), 35, PBPBMA. PBPBMA PMBPS Okamoto, PBPBMA. 3 2.,, Cotton, nm Cotton,,

4 10 : { ( + )2 22,52 [4 2( ( S)222 ) ] } 1053 PBPBMA ( CH 2 OOC ), PMBPS., PBPBMA,, 1., 24,. Table 1 Free radical polymerization of BPBMA in different solvents a Solvent M n 10-4 M w 10-4 PDI Yield ( %) [ ] ( ) Benzene THF CHCl Anisole Anisole b a Polymerization conditions : [ M ] = 015 molπl ; Temperature = 60 ; [AIBN]Π[M] = 1Π200 ;Time = 24 h ; b [AIBN]Π[M] = 3Π BPBMA , 27.. PMBPS.,.. Fig. 2 1 H2NMR spectra of BPBMA (A), PBPBMA (B), and the PMMA derived from PBPBMA (C). PMBPS 302 nm Cotton, PBPBMA. Table 2 Free radical polymerizations of BPBMA at different temperatures a Temperature ( ) M n 10-4 M w 10-4 PDI Yield ( %) [ ] ( ) c c c b c 2810 a Polymerization conditions : [M] = 015 molπl ;I : AIBN for 50, 60, 70 and BPO for 80, 90, respectively ; [ I ]Π[ M ] = 1Π200 ; Solvent : anisole ;Time = 24 h ; b [ M ] = 1 molπl ; c Precipitates formed during polymerization Fig. 3 UV2Vis absorption and circular dichroism spectra of BPBMA and PBPBMA [13 ]. PBPBMA, ATRP, 3.,

5 (run 6),.,,. Run Table 3 ATRP of BPBMA in anisole at 90 M n 10-4 M w 10-4 PDI Yield ( %) [ ] ( ) PBPBMA, 1 5,. 2(C) 1 H2NMR., = 6 8 = 5, = 316,,., 2 mmπmrπrr = 10Π30Π60. mm 10 %,. PBPBMA. 3 BPBMA, ATRP PBPBMA. 30, - Cotton,,,., PBPBMA 25. PMBPS,PBPBMA. PBPBMA,,.. BPBMA,. REFERENCES 1 Green M M,Park J W,Sato T,Teramoto A,Lifson S,Selinger R L B,Selinger J V. Angew Chem Int Ed,1999,38 : Rowan A E,Nolte R J M. Angew Chem Int Ed,1998,37 : Nakano T,Okamoto Y. Chem Rev,2001,101 : Wang Yuechuan( ),Ding Mengxian( ),Xu Jingzhe ( ),Wang Fosong( ). Acta Polymerica Sinica ( ),1988, (4) : Chen Chuanfu( ),Liu Weihong( ),Chen Yongming( ),Ren Changyu( ),Xi Fu( ). Acta Polymerica Sinica ( ),1996, (1) : Lam J W Y,Tang B Z. Acc Chem Res,2005,38 : Lam J W Y,Tang B Z.J Polym Sci Part A :Polym Chem,2003,41 : Okamoto Y,Nishikawa M,Nakano T,Yashima E,Hatada K. Macromolecules,1995,28 : Kwon Y K,Chvalun S N,Blackwell J,Percec V,Heck J A. Macromolecules,1995,28 : Percec V,Ahn C H,Ungar G,Yeardley D J P,Mgller M,Sheiko S S. Nature,1998,391 : Yu Z,Wan X,Zhang H,Chen X,Zhou Q. Chem Commun,2003 : Yu Z,Tu H,Wan X,Chen X,Zhou Q F.J Polym Sci Part A :Polym Chem,2003,41 : Nakano T,Okamoto Y,Hatada K.J Am Chem Soc,1992,114 :

6 10 : { ( + )2 22,52 [4 2( ( S)222 ) ] } 1055 SY NTHESIS AND CHARACTERIZATION OF OPTICALLY ACTIVE POLY{ ( + ) 22,52 BIS[4 2( ( S) 2(22METHYL BUTOXYPHENYL) ] BENZYL METHACRYLATE} CUI Jiaxi, CAO Hongqing, LIU Anhua, WAN Xinhua ( Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Department of Polymer Science & Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing ) Abstract A chiral vinyl monomer, ( + )22, 52bis [ 4 2( ( S ) 2( 22methylbutoxyphenyl) ] benzyl methacrylate, was synthesized and polymerized via both conventional radical polymerization and atom transfer radical polymerization. The monomer showed a specific optical rotation [ ] ( c = 012 gπdl) of 5915 in THF,while the corresponding polymer displayed its [ ] value less than that of monomer for about 30. In the UV2Vis absorption regions of ester and p2terphenyl side2groups,the monomer exhibited very weak Cotton effects. In a sharp contrast,the polymer gave negative and positive Cotton effects centered at 302 and 270 nm, respectively. These results suggested the formation of a chiral secondary structure of polymer backbone,the optical rotation of which was opposite to that of monomer. For a vinyl polymer like poly{ ( + )22, 52bis [ 4 2( ( S ) 2( 22methylbutoxyphenyl) ] benzyl methacrylate} ( PBPBMA),the most possible chiral structure was helical conformation of main2chain with an excess helix sense. The reaction temperature and solvent were varied to study the effect of polymerization condition on the [ ] value of the polymer. It was found that the [ ] value of the polymer was independent on the polymerization conditions employed. The specific optical rotations of polymers decreased with increasing molecular weight at beginning and then leveled off, consistent with the speculation of helical conformation generation. The content of mm dyads of PBPBMA was only about 10 % as estimated with 1 H2NMR by converting the polymer to poly(methyl methacrylate) ( PMMA),which was comparable to that of PMMA obtained via conventional radical polymerization. This might account for the lower optical activity of PBPBMA compared to that of poly { ( + )22, 52bis [ 4 2( ( S )222 methylbutyloxy) phenyl ] styrene},an optically active helical vinyl polymer with similar structure. Keywords Specific optical rotation, Optically active helical polymer, Chirality, Radical polymerization, Atom transfer radical polymerization