Determinationofstoichiometryoforganicconductors ... - Springer Link

Ru s s ianCh em i ca lBu l l e t in ,In t e rna t i ona lEd i t i on ,V o l .6 2 ,N o .7 ,p p .16 43—16 48 ,Ju l y ,2013

1643

D e t e rm in a t io no fs to i ch iom e t r yo fo r g an i cco n du c to r s b a s e do nth eETan dBEDOTTFt e t r a th i a fu l v a l en e s b ys p e c t r o pho tom e t r y * , b E .I .Zh i l ya e vaa andK .A .D z yu baa aI n s t i tu t eo fP r o b l em so fCh em i ca lPh y s i c s ,Ru s s ianA cad em yo fS c i en c e s ,

1p r o s p .Akad .S em en o va ,142432Ch e rn o g o l o vka ,M o s c owR e g i on ,Ru s s ianF ed e ra t i on . Fa x :+7(496 )5223507 .Ema i l :zh i l ya@ i c p .a c . ru b M .V .L om on o s o vM o s c owS ta t eUn i v e r s i t y ,D e pa r tm en to fFundam en ta lPh y s i c o ch em i ca lEn g in e e r in g , 1L en in sk i eG o r y ,119991 M o s c ow ,Ru s s ianF ed e ra t i on Sp e c t ropho tom e t r yw a sshowntob eapp l i c ab l efo rth ed e t e rm in a t iono fcompo s i t ion so fth e ETandBEDO TTFt e t r a th i a fu l v a l en e sb a s eds a l t s ,wh i chinth esp e c t r ah a v eth eo v e r l app in g ab so rp t ionr e g ion so fth er ad i c a lc a t ionandth enono x id i z edfo rm s . Ap ro c edu r efo rth e d e t e rm in a t iono fth e mo l a rab so rp t ionco e f f i c i en t so fth er ad i c a lc a t ionfo rmw a sd e v e lop ed . M a th em a t i c a le xp r e s s ion sfo rth ed e t e rm in a t iono fth et e t r a th i a fu l v a l en e so x id a t ions t a t e sand th ecoun t e r ion mo l e cu l a rw e i gh tw e r eob t a in ed .Th eapp l i c a t iono fth i sm e thodi sl im i t edb y th elowso lub i l i t yo fth es a l t sw i thth edoub l ych a r g edan ion sandth eb rom id ean ionb e c au s eo f +t 0u oET ponap ro lon g edd i s so lu t iono fsu chs a l t s . th er edu c t iono fET K e ywo r d s :r ad i c a lc a t ions a l t s ,t e t r a th i a fu l v a l en e s ,o x id a t ions t a t e ,sp e c t ropho tom e t r y .

T e t r a th i a fu l v a l en ed e r i v a t i v e se xh ib i te l e c t ronr e l e a s in gp rop e r t i e sandc anfo rms t ab l er ad i c a lc a t ion s .Al a r g e numb e ro fr ad i c a lc a t ions a l t sw e r eob t a in edb a s edon th e s e compound s ,wh i cha r ech a r a c t e r i z edb yth es em i condu c to ro rm e t a l l i ct yp eo fe l e c t r i ccondu c t i v i t y ,in c lud in go r 1, 2 A g an i csup e r condu c to r s . saru l e ,th er ad i c a lc a t ions a l t s b a s ed onb i s ( e th y l en ed i th io ) andb i s ( e th y l en ed io x y ) t e t r a th i a fu l v a l en e s(ETandBEDOTTF ,r e sp e c t i v e l y )e x h ib i tth econdu c t i v i t yo fqu a s itwod im en s ion a lch a r a c t e r , wh e r e a stho s eb a s edont e t r am e th y l t e t r a s e l en a and t e t r am e th y l t e t r a th i a fu l v a l en e s(TMTSFandTMTTF ,r e sp e c t i v e l y ) ,th equ a s ion ed im en s ion a lch a r a c t e ro fcon 2 du c t i v i t y .1,

X=S(ET ) , O(BEDOTTF )

R= Me(TMTSF ,TMTTF ) X=Se(TMTSF ) ,S(TMTTF )

Th es yn th e s i sands tud i e so fn ewt e t r a th i a fu l v a l en e b a s edr ad i c a lc a t ions a l t sa r eimpo r t an tfo rth eg a th e r in g 2a n ewfund am en t a lknow l ed g e1, ndd e v e lopm en to fn ew *A c co rd in gtoth em a t e r i a l so f XX IV Con f e r en c e"Cu r r en t Ch em i c a l Ph y s i c s "(S ep t emb e r20—O c tob e r1 ,2012 , Tu ap s e , Ru s s i a ) .

m a t e r i a l sw i thunu su a lph y s i c a lp rop e r t i e s ,wh i chc anb e u s edin mo l e cu l a re l e c t ron i c sd e v i s e s .3 Inth es yn th e s i so fo r g an i ccondu c to r sb a s edont e t r a th i a fu l v a l en e s , i t i s impo r t an ttoe s t ab l i shs to i ch iom e t r yo f –],w th ef in a lcompound s[D ] [An h i chi sd e t e rm in edb y  th eo x id a t ions t a t e( )o fth eco r r e spond in gt e t r a th i a fu l v a l en e D(Ani sth ean ion ) .Inth ec r y s t a lo fo r g an i ccon du c to r ,th eo x id a t ions t a t e( ch a r g es t a t e )o ft e t r a th i a fu l v a l en e ,to g e th e rw i thth ec r y s t a ls t ru c tu r e ,i son eo fth e mo s timpo r t an tp a r am e t e r sd e t e rm in in gsu chph y s i c a l p rop e r t i e sa sth econdu c t ionb andf i l l in gandth eph a s e 4 T t r an s i t iont yp e s . h en a tu r eo ft e t r a th i a fu l v a l en ed e f in e s th efo l low in gm e thod sfo rth ed e t e rm in a t iono fth eo x id a t ions t a t e: 1 )fo rth eETs a l t s ,i ti sth ean a l y s i so fth ebondd i s t an c ech an g e sinth et e t r a th i a fu l v a l en eco r ea scomp a r ed toth e mo l e cu l eo fnono x id i z edET ,5 2 )fo rth eBEDOTTFs a l t s , i t i sR am ansp e c t ro s cop y ,4 3 )fo rth e TMTTFand TMTSFs a l t s ,i ti ssp e c t ro pho tom e t r y .6—8 Sp e c t ropho tom e t r yi son eo fth e mo s tr ap idanda v a i l ab l em e thod sfo rth e d e t e rm in a t ion .Th em e thod i sb a s ed onth ef a c tth a tth er ad i c a lc a t ion sw i thth ech a r g e+1(D+) andth enono x id i z edt e t r a th i a fu l v a l en e mo l e cu l e s(D0) b e a r in gnoch a r g ea r ep r e s en tinth ed i lu t eso lu t ion so fth e –]i r ad i c a lc a t ions a l t(D ) [An c e ton i t r i l e ,ag en e r a lfo r  na 0 –]. 9 h mu l ao f wh i chi s[ (D+) [An eo x id a t ion (D) ]  T 1– 6 —8 s t a t eo ft e t r a th i a fu l v a l en ei sd e t e rm in ed u s in gth eco r

Pub l i sh edinRu s s i aninI z v e s t i yaAkad em i iNauk .S e r i yaKh im i ch e ska ya ,No .7 ,pp .1643—1648 ,Ju l y ,2013 . 10665285 /13 /62071643 ©2013Sp r in g e rS c i en c e+Bu s in e s sM ed i a ,In c .

1644

Ru s s .Ch em .Bu l l . ,In t .Ed . ,V o l .6 2 ,N o .7 ,Ju l y ,2013

Zh i l y a e v aand D z yub a

+) r e l a t ionb e tw e enth econ c en t r a t iono fr ad i c a lc a t ion( c andth eto ta lconc en t ra t ion o ft e t ra th ia fu l va l en ein + +c 0) th er ad i c a lc a t ionandth enono x id i z edfo rm s(c : + + 0 = c/ ( c +c) . Th eBou gu e r—L am b e r t—B e e r l aw fo r th er ad i c a lc a t ion 6 s a l t sop e r a t e sfo rth econ c en t r a t ion so f10–4 mo lL—1. Th i sm e thodw a su s ed fo r th ean a l y s i so f t e t r a th i a fu l v a l en e s b a s eds a l t s ,inth esp e c t r ao fwh i chth eab so rp t ionr e g ion s o fth er ad i c a lc a t ionandth e nono x id i z edfo rm sd id no to v e r l ap .6—8 How e v e r ,apo s s ib i l i t yo fapp l i c a t iono f sp e c t ropho tom e t r yfo rth es tud i e so fo r g an i ccondu c to r s b a s edonETandBEDOTTFw a sno tcon s id e r edsof a r . Inth ep r e s en t wo rk ,w ed emon s t r a t eth a tsp e c t ro pho tom e t r yc anb eu s edfo rd e t e rm in a t iono fs to i ch iom e t r yo fth eETandBEDOTTFt e t r a th i a fu l v a l en e sb a s ed r ad i c a lc a t ions a l t s .W ea l so ob t a in edth ec a l cu l a t ion fo rmu l a sfo rth ed e t e rm in a t iono fth et e t r a th i a fu l v a l en e o x id a t ions t a t e andth ecoun t e r ion mo l e cu l a rw e i gh t ,a s w e l la sd e t e rm in edth e mo l a rab so rp t ionco e f f i c i en t s (m . a . c . )o ft e t r a th i a fu l v a l en e s inth enono x id i z edandth e r ad i c a lc a t ion fo rm s .W ea l sor epo r tth er e su l t so fth ean a l y s i so fs e v e r a lo r g an i ccondu c to r sb a s edonth er ad i c a l c a t ions a l t s ,who s ecompo s i t ionh a sb e ene s t ab l i sh ede a r l i e rb yXr a yd i f f r a c t ionan a l y s i s .Th ea g r e em en tb e tw e en th eob t a in ed v a lu e sandth eXr a yd i f f r a c t iond a t acon f i rm sth eapp l i c ab i l i t yo fth i sm e thod .

Ex p e r im en t a l R e a c t an t sET(98% )and Cu (BF4) 19% CuII)w e r e 2•6H 2O( comm e rc ia l ly a va i lab l ef rom A ld r ich . T e t ra th ia fu l va l en e eCN ]0 BEDO TTF( s e eR e f .10 )andth es a l t s(ET ) [BF4•M .5 11 (ET 11 (BEDO TTF 11 ( 1) , ) [BF4] 2) , ) [C lO4] 3) , 0 .8 ( 0 .5 ( 11 a 12 (ET ) [C lO eCN ] ( 4) , nd(ET ) [B r •C2H4(OH ) 5) 4•M 2] 0 .5 ( w e r es yn th e s i z eda c co rd in gtoth em e thod sd e s c r ib ede a r l i e r ,12 (ET ) [ZnB r l2] 6)w a sob t a in eds im i l a r l ytoth ep ro 4•C6H4C 0 .25 ( 13 c edu r e . A b so r p t ions p e c t r ao fso lu t ion sw e r em e a su r edonaSp e co rd M 40sp e c t ropho tom e t e r inaqu a r t zcu v e t t e(l=3 0mm )a t2 93K . D e t e rm in a t iono fm . a . c .o fth eETan dBEDO TTFnonox i d i z e dan dr a d i c a lc a t ionfo rm s . Th ei somo l a rs e r i e so fso lu t ion s o fETo rBEDOTTFina c e ton i t r i l ew a sp r ep a r edb yas equ en inequ a l t i a ladd i t iono fa8 .6 m M so lu t iono fCu (BF 4) 2•6H 2O( –5 M s o lu t iono fth e po r t ion so f0 .12 mLe a ch )in toa(2—4 )•10 co r r e spond in gt e t r a th i a fu l v a l en e( th ew e i gh edamoun t s ,vo l

A  =316 1 1 1 .2

2 =4 64

9 10 8

8 0 .6

0

1 10 9 400

600

/nm

F i g .1 . Th ech an g e sinth eab so rp t ionsp e c t r aupono x id a t iono f .49 •1 0–5 mo lL–1.Th eso lu t ion BEDO TTFin M eCN ,c 0 =3 numb e rin c r e a s e sw i thth ein c r e a s einth eamoun to fo x id an t . Th eso lu t ion w i th n=1con t a in son l yth e Cu (BF4) 2•6H 2O nono x id i z edBEDOTTF . um e s ,andcon c en t r a t ion sa r eg i v enin T ab l e1 ) . Th ech an g e s o c cu ra lmo s tin s t an t l y .F i r s t ,th eab so rp t ionsp e c t rum w a sr e co rd edfo rth es t a r t in gt e t r a th i a fu l v a l en e ,th entho s efo rth eg r ad u a l l yo x id i z ab l eso lu t iona f t e re a chadd i t iono fth eo x id an t ;th e so lu t iona f t e rm e a su r em en to fth esp e c t rumw a sr e tu rn edf rom th ecu v e t t eb a ckin toth evo lum e t r i cf l a sk . Th ee r ro rem e r g ed f romth ech an g e sinth econ c en t r a t ion o ft e t r a th i a fu l v a l en e c au s edb yth ein c r e a s einth evo lum eo fth eso lu t ion(