Jones, Alan J.

Leznoff, Clifford C.

Svirskaya, Polina I.

YorkSpace

Characterization of Organic Substrates Boundto Cross-linked Polystyrenes by 'C NMRSper:lroscnpyAhrJ. IoncrtTb. Natlonrl NMR Oootn, Autraltm Nattongl Uniffiity, Csnbqr8' ACT 2600 ArrstnltuCXludC. L€doF rdffi. L MrLryrDoartDcat ol Ctsnfstry, York Univcnlty, Dqwiw, Ontrio, M3I lP3, GngdaD. trC NMn ;r..tr ol rrldcrrr|cty d rrydclffill bod rD 2.1 cru.fiftdfolyrfilrcatlryhcell.firA nd:tl, gwldad t: nfu cn tc rddady rdlro lfo sC *rdcj rffltol nolyr+oulttl$f Uofol, rolrc+od lnodFf rfr:rr ol tr rlndql dd EO((&ILOE lt=l 4 67,9 td10L d frc ded bilc&Gr h lh*o8i lh ryocdr of heef ghquoE tcpsmd. qC itftrfittrtty cuaUole, rtfilrbf ruc ft[ h. frft.. fftt{ G{hcnt ar &rlinThe detennhation of the structuo of organic zubstret$ bound to ame-'linlcd polystFencs is a problemof grcat int€reot to wortcm involvod ln soHd pbarcpep&fc sptbcsb,r organic syuthcris oo solid ph,sses,'1rnd functftrnallud polymors for use as ohsmirxl roag-ents.5'' Chemicel methodr of analysis, sucfi ar fmc-tioaal grotrp aralyais, elemental analysb, and reuovalof the organie tubstfatE from the polyoer can betime-consumin& inacqnate and destnrcti\.€, rmesinplc phpical ncthodr such as IR ad ESRspccrros-copy give lfonitcd idormtion on the exact etructuro ofthe polym.er-bound substrate.sstsC NlvlR rpcctroaaopy has bacn applied to tbecharactotization of a wide variety of itrEoluble bulkmatcriets,cro lnrt there have been limited reports on-cerniDg tllo ttc Nl,G. spcctra of orgadc aubctrstesbound to cross-link€d pollrtyrene.rr Howevcr, twovcq' rcccnt publicetions,rars concerned with the rue oftf NMR spcctra in the dercrmination of theciloromcthylation lcvclg of cross-linkcd pollttlrlenea,pFompt us to report orr findings on ths tcCNMRspecta of a wkle vriety of organfo sub6tr8tes boundto 2% qocs-lirrlccd polFtyredes. Our intercst in thesyntheeb of irsect pheromones on croes-linkedpolystyrenesar+l5 hrs led rrs to pnepare a serles ofpolymer-bound moootri$ ethen of symrnetricaldioisl+16 and more complix polymer-bound syntbticint€nnediatc. Tb find products of these syntheeeswerc charactrrized by removal of the synthetic pro-duct from the polymer,l+r6 but the structure of thepolymcr bound interhedlates or thcir puity wrl notadequately detcrmined. r3C NMR spectroscopy allovscharacrerizatim of tbcse fosolublc polyner-bound or-ganic substrat€E for ths first time.I jdutbtrr to Tlte! mcpondere ehouH be addro:d.EXPEBIMENTALCarbon-13 NMR sp€ctra wcrc determined in tlreFourier mode using a Drukcr HFX-270 cpoctromcterat 6?.89 MIIz. (It b worth noting thar gmd spedramay be obtained uslng lower ffeld strength spectrome-ters.) A Nblet 118O corrputer wae used to scqufuidata. In getroral, a sp€ctral width d 15 kIIz was ob'sewed in 16 K dsta poinb urhg an appmxinato pulsoanglo of 6S and averaging 2-4 K acquisitbm. In sonecss€F more ecqubitiom waro obtaiucd to anhatrcc tteoignal-to-noirc of low fute$ity p€als, and dclays of1(F15 s betwoon pulses were urcd wbn integntlonwas desired. SrDples wcrc, oontain€d in 10mn od.tubes. Solvent induccd s*clling ol 0.?5 g of polymsr in2-2.5 al of deuterocbloroform generally produced anadequate sanrple volume of the eppropriat€ slurryconsistency. Howev€r, when tbc soM polymer beadsize war *mall a greater weigfu ol golymer per unitvolume of rolvent was required. Internal rofetencingwns ac,hiEved wing the oentre peak of deutorc-chloroform (g : 77.0 ppm).17BESULTS A!'D I}ISCUSilOI\IGcrrl lcgtuclAs ooted by Manatt ct aL,rz solvont rwollon cro6s-Iinlod (1-2%) polyst',ron€€ shdied rl shrri€s exhibitrelatively narrcw t"C NMR signals, and only trivialdiftrences in chemirrl shifts.,rfot b€tw€€n roluble andsolvent sc/ollerl inmluble polptyrener At tbe oub€tof our studi€s we invoked the addt&nal premis€ thatsegmcntal motionr8 of side 6ain substitunnts attachedto the backbono polymcr will nrult in sharply deffnedSppmtgur. 1. Tha tsCNMR sp€dra, dotarmln€d at 6t.GlMl|:, of $hrant {deutargdrloroform) crollan shrrrl.3 of (al E${rnsn 2*divlrylbsnzano Gros{lnl€d polf'styrone, (b) poly*frl3 bound triM alcdrol; inrd lhosr! the sfine sp€caum aftar roh/ernmpoEtion 6nd r$uapondon, (cl the potyrnar+ourd monfit$l lthar of haancdiol 1; incat b thc apocrum obtalnad ualng I p!1.€dclry ot los, (d) u|€ polymer+ound motllt/ln lphonsb derhra$ve 2 sf t rnd (c! ths potymoFlound Crz bromoalkyne 3. Th€ lid€dpln e61bon ltofi! eru ilrmb€tbd lrom the trltlrl sdur amhorlm dte. C--4 tsilrs to ff, ttltyl cerbinol carton and M8 to lh€rrotMsulphonrto rndrvl crrbon,r3C NI\&. sigdrk fo'r tbc uore ooblle portiom of the8ub$tituent molecules. tn sddithn, out observationsindicste that reronaacet of the carbon atms do6e tothe pol5mer binding sfte arc b'rcadcned relat've tothqo associated with portiors of tbe side c.hains consi-dered to be more freely rotatiru. Clcarln thb iodicatesincreaeing Tr and Tr valucs lorr ttc carbon atoEs oftte eida chain subctitucnts with dirtancc from thepolym.er backbone. Fhrthermore, we e:rpeded thattrace mat rialr (not necessarlly polyrcr-bound) woulderhlhit ttp normal liuc widtbg of colutbn epcc"tra. OrIrqualitativc visw h eubctatrdated by tbo very recontdetailed analyrb of the moleoilar dynamics of polym.ercbains in solution provided by IeW et aLt' However,shile qualitativcly vali4 tbe rlmple modcl of irotropicmotion in polym.er ride c.balns crntrot be quantitatfuolyapplied in the analysb of relaxation and nuclec Over-heuser pannetors,t' but @n clearly aid in thedifferentiation between mol€culaf, eites involved infrco or restristcd motirm, Mot rignificant fton anasgignment point ol view arc tbs obvious broad liles(relatiwly shstef, T2 valuca) getc,atty agrociatod withthc first thres carbon atomr of lhe eide chsin sub-3tiorena.Figrr€ 1 shom a montage of specha erisingfrcm aicquercc in a polym,or-borurd syntheb. In the 2%cnm-linkcd polystyrene spetrrum Ffg; 1(a)) llCNMR ripals drmderidng the qnaernary elomatkc*bons (145.8ppm), the odo ald, Frsra ca$oos(128.0ppm), the paru carbou (125.7ppm) and thebaclborre uethylene aod methine carbons (,1O.4 and 3.0pp) are otxerved. Tto rpectrum of polyner-bound trttyt slcohol, prceama acoording b publlshedprocodurc,rs is shoxm h HC 1O). Th oharact€rbticbtroid line at 81.9!'pm b attrlbuted to the quatcrnaryaarbon atom in tle tripbolylcarbinol gmup and thrt at147.0ppm to tb c-cartorn in thc phenyl ring (cones-ponding carb6 in tdtyl alcohol 79,4 andl49.2ppm).m Tbc sbarp reaonatrrs ar 67.9, 67.0,65.8 and 15.2ppm must bc anributed to iurpurities.The prcsonce of tbe*c iqudtiet ptampted u8 toadhere stricdy to ow publhhed procedwe for thepnparation of polym.er-boud tdtJd alohol.l5 Im'puritb r,ere ok€ned in mme prcpsl?don bot&eswhen tlp bcnzophenone s's stirrad ovornfuht *ithpoly,rner-bound phenytlithiun. In fast, we ruggest thatoptimization of reaction yields can bc achicved bymonitoring tho r3C NMR spedra of the producs.Some inpuritics werc abo lemoved by solvont evap-oration end rcsuspension to provido spectra with zeroor r€duced iotasities at 15.2, 65.8 and 57.9ppm.Ofi-rooona@ Epcctrc aDd atrrcletiffi crith literaturedata suggest ihst the 'fuprrity Fcak' arise ftom sol-\.ert sbifted or polymor-bowrd ethylbenzene(15.2ppn, Iiteratue,n 15.8p,pm), benzyl alcohot(66.9ppm, literature,z 6a.5Wm) and trro tertiaryaliphatic alcohol fuuctions (6?.8 and 65.7ppm). butnot rcaction totvsnts,rs such rs N,lrl"N'-ttl'-tetra-rncthylethylenedlamine (6 57 ard 46ppm)."The spec{rum of the pollaer-bound monotrirylether of hexanediol 1 shown in Fig. 1(c) b characteris-tic ol many of the polymer-bound subetrate speciesstudlTal. Notably, tbe polyrtgcne rcsonanoos arebroadened corrpucd to thco in sfaight polystFen€s,@-rr-+-{orrt"on f R-H(D|_rr4-(qthe-c{o{2bBr 2 R=GOzMeQrrr+{o{};HH 1QlTF4(CtlzLC-qCfl?lftL 5Q-Tn-O(C1l2lCB+H(Cl{"}aet 5GFTr-O{cHd{a-dQ+l*,t+(oUrc|t,where @ danoteg poltEtytEn3 blc*boneand the p*ubotituent shift (+4.2ppu) mmpared tothe polyu.er-bound trityl alohol qusternsry carbonchardctertrcs etbsr formation The notbnal p'roperdesend rheir eftect3 oo tho relaxation behgviour of tlEeide ctais deady produce two distinct groupr ofrgsonares; low iatensity, short T1 (-0.14.5 s) at26.L, 3O.O aod 64,0 p'pm, and highr iotcnsity, longerTt (-2-3 e) at25.7 ,32.6 Ndd 62.9 ppm). (T, cstimatcsare derived lrom c<ymideretim of lhe iatwity eftecrsobaervod ia the spcrtra uring diffcrent acquisitbndela'6.) Ch$mical chift coroladom nrith hexancdiol,the monotrityl cthcr of he,nnediola ffable 1), alongs.ith the qualitativo relaxatbn considerations, estsb-Iishe$ tbe order of the rhifts given in Table 1.Cbordcsl ghift additMf b ilhntrat€d in tbe methyl-sulphonate derivative 2, ar shown in Fig. 1(d). rypicalp- and 1-subctituent shift of +7.1 6nd -3.6pp'm arcnotcd. The rrery broad r€ronsncer 63.1ppn, snd thelow intersity signds tt 81.9 ed 32.4ppm, Euggest tbspresenoe of the unreastcd polymer-boundether ol hor&rediol aad pollmer-bound trityl alcohol.The cmmonly occnfiitrg 'i4puriti€s' wcre also ob-rcrved in the unerraporatcd 6amFle.Figure 1(e) ghmrs the lrC rpectrum of a polyrncribound Ge bromoathme 3 d€iid using aa altenativcsynthedc precursor, ttc morctrttyl ether o{ ethyleDsglycol. Conftrmation d tho assignnents gfuen in TableI b obtained by comparison with the spectrum of therEL rrc drdcet & ol !.accl.d d.ffi hF$Er+mdttrfrdtCrbn }dfio.f kWndja613 BlAna 20.o81.8 81-8@.8 !9318.8&78724924.9n73:tL7s.9s5 88.6t!1 8lt02 qt.o3 28.t1 2&75 3:L86 82.a7-a-9-10t112Msr n'2Carbinol carbon 88.2 S.2,6&aAB(fr.2,(21?,D5YFTrOf"*'Edc c*uln numberEd frarn flra sthar anc*rorlng rla, ! pnmwith lripoct to TilE.buG ghltte ln ihe monotrM €iltEr dt hsnedlol S 605, g).O,28.1, 2e0, 32-7 and €3.0 pom, trftyil grcup t 48.4, t+f,5, 128.21?71 at|d l2A8plh.'cf. rt dr'rft8 ln l2+rcmo€dodo{ryrtd, el,.t. AZ 8g.;6,7.4.4 le7,n7,&4 283. 28.9, n.1,Xn lrd 3A7ppm.c Polymer-bound tiV alcohol.'Thc m€itntl tGsonance of ths mcsVlata gEirp.Ilbt 2. rt .rF,ft.t ffi oI Oo potsrar-tmd {motttg cafr.{! ol tu qrDn rd.dtnol EO((rilOE _12at.8 69.3Icito6 n!.a!bn'aaE 7n2btcros2,7 e.9zAJ gL1 6iL84 B.a 26.4 ?pS e.76 640 l).0 26.1 frJ dr.6 8aA7 6a5 flro fr2 a2 25.o 348 Gn39 85 :n,0 25.2 6J AA 83 84toe a.6 r).r 2&2 21A AA nA nA'Sid! chsln rumbdEd from tha tM odror ancloring rlu, E ppm with lepoci to TMSD For n =2 mG.Vlrb d€rn sthr€, prlrrlpal componem drnr 6 OZ: 713, Gl: 60,8 and Mc:375pgrt""t tscppflr In thc monoirtVl 6tl|0r of dacrn€dbl: phefly'l caftom t14/L8, l8.q, 12tG lnd12G$ ppm, carbfnol cafton 88.4ppm, rFtftrden€ 8 7. n 1, 8& An,',g.s, A.A EL 6t,ELg !r1{ Glopffri.analogol8 polymsr-bound trityl ether il of l-butyne-{-ol (61.8, 20.0, 81.8 and 69.3ppn), d. the uC shiftg ir1-butyne-4-ol" 60.8, 22.7, 81.5 and 70.1ppm. It isudoftunpte that the linos at 81,8 and 61.8 ppm arc sosimilar iri sbift to tho€e of characterfutic carbons inuscacted pollrmer-hound ttityl alcohol and its glycoletlrcr (81.8 and 61.9 ppur), einoe thb precludcs eitims-tion of the synthetic prrity d tbe polym.er-boundspocirx.Symcfti.rt itd dcdrdimgThe TC $enical shifts of tte polymer-bound moro-trttyl bthen of the symmetrical diols HOtClIr"OH,where n = 2, 4 6, 7, 9 and 10, along with the mx$atcfor tlo n =2 csse, are givcn in Ta& 2. (Ihp data fun-6 arc rcproduced from Tebh 1 fm convaniene.)Generally, specta exfiibtt Ine intessiti€s asociat€dwith rhe motioual proportieo described above. For then = 2 case a brcader higber field methylene (6f .8 ppn)b ascigned to tie C-1 cubon by analog *ith ficcorroqonding carbon in the ethyl ether of glyol.5 Inthe cace of some synthFdc batches tbe spectra ofearlier mcmbers of the series also exhibited r€*o-nance attributable to approxiEat€ly 30% unreac.tedpolymer'bound monotrigl alcohol (81.7 ppm), In ad-dition, the mcsylate of tlre n = 2 ether, while exhibit-ing tln characterirtic methyl group at 37.5 ppm, alsoebowed the presence of up to 30% unrpacted alcoholThe methylouo nosomtrGo of the d€€ylste dcrivatiwwere *harper thn' in tlc pr€culsor almbol inplyinggreater motional frroedom, but unusual additivity shifttof -0.9 ard +zDpm are noted for tbe B- and a-positi,ons, resp€ctivcly. For z:4 the terminal C-4methylene resouanoe is more intense thsn oth€r line6in the specrrurn, while the slgnal of C-l is very broad,consistent with segmental motion, aud by analog withth€ n=6 csc rhown in Fig. 1. For a-?, 9 and 10rpccrra fuilar to thar of n =6 ere also ob'rervGd andossigunents tollow from addttivity relatiomhips. Noevidoroo lor ureacted presurtors wa$ obvious in thcepcctra of n:7,9 or 10, Assigments for thc C16chaln sere decived by comparison with the monotrltylctf,cr of dccanediol.aLffiSlrictIn r$orts to pdoqrc spcctra iu other sampler, indud-ing ttc C12 dkyuc 5 and the Q2 alkene 6 a distiDctproblem arose. The swelling volume of the polfmorboads vas clearly the dominsrt factor contributing tott3 quality of the reeults. Att€Epts to increase thegolwnt srrellitrg udng the alternativc solvcnB pyridineor msthy'ene chloride {'ere not gumsfirl In ronccar€s starding itr chlo'roform lor a prolonged period (lrrcck) ilcrersed the swelling volure, rcsulting iofavouratilc epectra (for example, ia the caso of the C6diallyne 7) compared with thac obtahed for'frerhlyprepared'samplee. The failurc to obtain clearly intcr-pretable rerultr in rcme cases may also arise from thepwibili$ that thqe are fe*e. qide chain substitu€.nbpcr unit volunc of polymer, or that modonal frredornis inhibited by inuamolecular bonding ontribution: ormodificatiorn in the stereochcmfutry of the clleriaiDs"le Cbarly the initial she of the dry polymarbcads in these cases ir emall,sr thso i! all other exam-ples sttrdie4 ard melling by solvcnt is reduccd by atl,sagt a lactor of two. It is apparcnt that qntems of thlskind should be studied 'ring mlid-state NMRaethodS.lo It is of sornB intctrest to note that thesynthetb qit€rion for dctermining the b€st conditionfor reactions of polym.er bound subetrat€s also relieson naximizing solvent swelling volumeg.RETtsBENCES'1. B, W Erlc*gon 8rd R B, Menffleld. In Thr ftotoint,3dEdr|, Vol. ll, .dl&d hry H. Neuru$ and R L Hlll, pp. 2dl-52r.Acadomlc Prsr, New Yod( ll!lt6l.2, G C lcnofr, Aca Ch€m, Rar. 11.3f, (l9,Bl rnd r.f€rsna€8thcrein.3. J. M, J. tu*t ?bt?rfi.dEn tl,86il (1Sl).{. A. hfiomlt ond M. Kraur. Cftern lec$nd. 9, 118 tfg8l,G, MdmGlF ehd P, Raucr, turc ,vppl. Chrm. 51,2313f 18791; J. R6b6k Jr. Ttuahad{oh 3q' ?2t (1ft9}; w' }l€ia,Ansen. lvk,krc,moL Clr,mT6lTI, zt:l (1ft9l.E. N. K Mathur. G K. Natug and R EWI[']!|Y|r, FotytrortraN& tn Ooanic Ctumlstry, ptr gr-52 Aoademlo fto83,New Yqk t1ft01.& P. Tekaty lrd E. Tur*r, it cru.nof. Ctr€m. tS, 2f l {19791.7. K Yolot. A Abe, S. H€tkt, l. Sa*al and H. Seile.M'E'oanlfr,t,a tL g5 (ltf8l.8. J. 8€hs6tor, ln Topbe ln CErbon -t3 lvlt R Spedroccop%cdlbd bt G. q bvy. pp, f4F20& wlley{nFnd6nco, N€rrYort (19,41.9. C. A fu'frB, A Rtdln rnd \il. Tdlr, Mmolurlrc lt l&0oErl.t0. A" Eunn, iJL E A. Grdbv, F. K HanE, K J. Plcler rn<l B. J,Sry, J. Ctrc.n, Soc, C|tcG ftrnmn 15 (l$tl.11, H, Ebmlldt, G. Llkenyoo E L PaclFr ard J. Slndalr, J.An dr!m. Sc 94 tSg ll$tt).la S, L Manaf, II tlorow'rE' R llorow]ts 6nd R P, Pim6ll,tu.1. ClEn. E2, 15ZA n$l).13. W. T, Ford gnd S, A Yecoub, J. &9. Cft?n. aA 8tg (1*ll.14. P. l. $rtultayt. C, C l-s|ofi, J. lrlitFthorcuxr and J, Elrlng, J. Ct|€m. Rrg. D.t 2+ lg llyrl),16 T. M. Fyl6 srd C, e te|dfi, c.n J. Cbrm. ?f, eF (lgral.15. G G, t znofl, T. M, Fylar lrd J. Wbdrsrrton, hn J.Cft6m, S. lrr(| (1t171.17, ttemfr. Shlrp ond Dofim6, ,$trdy Ffferct'r. drtr l'lEzl.1& D. M. Doddr€ll and A Allerhan4 J. Ai. Clrsft. Soc 3q,lE66 (l$flh G. C. Lor/y, J, CIEG Soc, Orara, &{rrmun,760 lr$r21.19. c! G l3lrv, P. L Riilldl, J. J. Doqftter, D. E Ard€on .nd LMandeltEm. At]Hb'n Ctpmfo',l S6.:1rty qmtpdalum$er|ea,, #14 €dfted W A E Woodwad .rd F. A Borsy,Armrlcrn Cl|.rnlcal Saddty, Worhlnqton. DC (1SOl.20, G. A. CN!h, P. W, w*tonfisn .nd J. NHilmur!, J. AmCtE fl. Soc !q S{8 (1Cr4).21. W^ &a:nrer, L Ern6t, & Franka, F. Ct€rlrer(b rnd A Haldt,Cilfun-lE,VMfr $ecua, Deta, V6rlrg Ghsmls. Welnhclmoe79'.2' L F. Johnson lnd w' C Jantorvltl. Grrto*t3 ttflfiScct , Wlby-lntsrrcl€D€, New York (l$ra.23, Rat 21,3p€ctrum#7&.2{, e q lnnofr ard J. Y. Wmg, Crn. J. Ch6rL 50. 2fll2(lCnD; J. Y. Wons snd C, C. tnnqf, Gen J. Chem. El,zdr (1sr3).6. W.Z4#f,xum#e2.

Characterization of Organic Substrates Bound to Crosslinked Polystyrene by 13C NMR Spectroscopy

https://yorkspace.library.yorku.ca/xmlui/bitstream/10315/6415/1/LEZ052.pdf

Characterization of Organic Substrates Bound to Crosslinked Polystyrene by 13C NMR Spectroscopy

Abstract

Similar works

Full text

Available Versions

YorkSpace