EXPERIMENTAL STUDIES ON SOME LIQUID CRYSTALLINE COMPOUNDS

EXHIBITING SMECTIC ORDER

Thesis Submitted to the UNIVERSITY OF MYSORE E

for the Degree of

&cim of $@ilueup~g

BY B. S. SRIKANTA

Liquid Crystals Laboratory RAMRN RESEARCH INSTITUTE

Bangalore-560 080 JUNE 1984

DECLARATION

I hereby declare that the thes is was composed

by m e independently and that it has not formed the

baeis for the award of any Degree, Diploma, Associate-

ship, Fellowship or other similar t i t l e .

X Q W S Z y Oh* this the@$# hP0 been

W#tpc+aed by %Tf B.8.8FikWIM Wagd tRI irrusd8.0lf-

p@%l;lme#ra wmi& auh by hkn at b;ko LiqaZd CFyskirZa

Ileboratory, R a m RaalmM Iati%?Ltu$w, wndsc my

rpupcrrvlaiar, The tab3aodt & a t l o r OP %hie iekr@~rier

tuna no% pwioursXy iom& the, W0is tlf the awml

of m y degree, Bbp%ma, assw)ia$@@htg, ica2lmehip

~ t h @ T ~ i m i X ~ O?L*Z**

The work presented i n t h i s t h e s i s w a s c a r r i e d

owt i n the Liquid Crys t a l s Laboratory, R a a m Research

h ~ - k l % l h t ~ ' ( Wangalore, under the supervis ion of

D~.,N.V.Madt~~isudaxm who tms always been an indispensable

source of encouragement and advice. 1 arn highly

indebted t o him f o r h i s i n s p i r i n g guidance, constant

support and keen i n t e r e s t i n tho work.

I oxpress my deep sense o f g r a t i t u d e t o

Professor S . Char~drasekhar f o r h i s invaluable help,

encouragement and u s e f u l suggest ions throughout t h e course of t h i s work.

X am g r a t e f u l t o Dr.G.S.Ranganath for. t h e

vnluoblc s t~gges t i ons given by him dur ing t h e prepara-

"tor1 of t h e t h e s i s .

I am indebted t o Mr,M.Subrmanya Ra j U r s who

synthesized most of the compouxads s tud ied i n t h i s t h e s i s .

My thonkn ?re due t o Dr .R ,K .Stldashiv and Dr .V.Surendranath

who wtarc .&d enough t o provide some l i q u i d c r y s t a l l i n e

compounds.

1 thank Dr,K,A.StuBesh, Dr.R .Shashidhar and Dr.B .R . R a h a who helped mc i n many ways; Mr.V.A.Raghunathan,

Miss K.R.Sumnthy and Miss R.Pratibha f o r t h e i r cooperat ion

and he lp i n reading the manuscript; M r . K. Subramanya,

Plr . M .R .Subrahri~anyam, M r . B .Subramonyam, M r .P.N .Ramachandra,

M r . R .Vasudevan, Mx. , V .Nagaraj , M r .T .Ruclunongathan , M r . K .T .Rala!criskman, M r .A .Ratnukar, M r . C .Rarnachandra Kao ,

M r . Mohamed Ishay and other f r i ends i n the I n s t i t u t e

f o r t h e i r whole-hearted cooperation.

P thank M r . S.Raghavachar f o r h i s adept handling

of the typing work.

My thanks a r e due t o my colleague Dr.C.Venkatesh

f o r h i s help and encouragement.

My work was made possible through the grant of

study leave by the Management of the National Education

Society 02 Karnataka, Bangalore, and the Pr incipal ,

A.E .S .National. College, Gauribidanur . I remember them

with gra t i tude .

F'inall.yy, I thank my s i s t e r Smt. Manjamma and

my brother M r . B . S.Srinivaaa Murthy f o r t h e i r encourage-

ment, cooperation and sustained support.

C O N T E N T S

FREFACJ!!

C h a p t e r I

C h a p t e r I1

C h a p t e r I11

C h a p t e r ITT

C h a p t e r V

C h a p t e r V I

C h a p t e r V I I

Page No.

k

INTRODUCTION 1

EXPER IBENTAL DETERblINAT ION OF THE C!IRVATWRE INDUCED REDUCTION I N TI33 SMECTIC A - NEMATIC TRANSITION POINT 30

X-RAY STUDIES ON THE SMECTIC A PHASE: EXHIBITED BY SEVERAL STRUCTURALLY RELATED COMPOUNDS 5 5

DIELECTRIC STUDIES ON SEVEML STRUCTURALLY RELATED SMECTO- GENIC COMPOUhJS 85

ELECTRICAL CONDUCTIVITY MEASUREXiENTS ON STRUCTURALLY RELATED St*ZCTOGRNIC COMPOUNDS 1 28

STUDIES ON BINARY MIXTURES WHICH EXHIBIT A MAXIMUM AS WELL AS A MINIMUM I N THE A - N TRANSITION BOUNDARY 139

EFFECT OF SKEWED CYBOTACTIC - - - .- - - - - -

STRUCTURE ON THE DIXLECTRIC CONSTANTS AND CONDUCTIVITIES OF SOFE BINARY MIXTURES EXHI- BITING THE. NEMATIC PHASE 181

lnVal.;Ci$atiom ~@mi(ib out by t;W aa?har @a .Ohr

I ?Pine firtst i;uwtPtative @tu& of the a f f e o t a a u ~ a 3 fidl~tortian on the smectic A - nematic

l i r w i t 1 , o n pain* rrhPoh ie etnal@&ou& a5 bhe in f lueme @1: ca m@@ti@ fiflld atn the aruwr aondw?tcr-aerml, ~)(btEd& t itiaa (%hrap%ar i;f ).

2 BIuJllarar oa the pkybf u a l psopes%iear ef srcveral ratruo &rally rela%& ww w 8 wen&@ cowowas. XsteratetZWy, thaae imeas%iga$lollrs~ bate bad to .e %A'& epeaaPag, BA- gg t m e i tion lab.& the+ reve**@rl o f the mxXm o f darslea%aa ausin&obropy CobiapSexe III, f V aml V).

5 imr%ls~ltaQiom en two blrrurgr aixturarr exhi- BitSna: sn Snduo.od acmaelrla A pM~le@, %he rswrkable iaafure o f %sea mixbwera b a l w %hat they ahow i a errllrtLCian Oa %)la oomnzy oB~seasd arwlimm, a srgLl define8 sixkinrum t n t h e ~metitt W -lam@tio hmmlt;lan bt4uMwy (gBapt@z VZ).

order on $he diairrleo$rict a d ooMw%&v%%y propara*& @f binary IBlrt~mi8 exhSbltlng Che olmaZ2a ptlae* A sfrlking new raedtr ob%afnad la fhwe ehdleiet, tp &a% t M

Xn oltikjpeex f we &*a a $camrmX Sndrodu~i;lon

~ C P the @ M ~ $ @ Q $ O I ~ ~ L B F o f Ches theail81 auld dlff~aicartba Cho

bscirmouad. werk err the tagiatsu dfxs@ulrsr$ la h 2 a r

ehapewr, 9km satXs%%t nsw ree~tcs oentdmted dsr

ohapewe SX - YXX ash n

The @rdet gwalaagltee Qf3uaxao$ariarLnl?; %he s ~ a h l o A

pharrsu h u twa cmp0maentrs. via., the q14rgtMa mtl the

@&"e OS the one diaubneirtnud. du~asl2tiy tt&Ver %Phi@ i s

ernailo&aurp f;o tiha order @arOl%a%h~ & @ ~ I B U ~ Q I T Z Z U ~ ~ .

gurh:;er, QanlChtaQy u f t h e Zuyw (hioknrrsaa Pn Ws

meotie, A aeda no* 3210~ ia owl 3 tygve s f digtar- 3 %&lion, n &as a writ v@al;us, @elk& tam d%rceo$or,

@low the p~eafsrmd 8isrcrZion of ocLenBat&on oat %he

moX@auJerr, 3hls i a r airrrlct~@er~~ f o flla expu2plton of a

nrcrlgu;6a$&e Piallt by n suyretra&nra:tox. &acrau&sriw ?it%&@

betwsaa %ha amon8 wlrbsss arwcstia A-mtsm.baa

tzmsitien U ~ P ~ ~ B , F e w j ~ 3 ~ O L . ~ I O F L a 1~upr0011 twbr-

naaaal ararbssS t m n l t l o n War a mrormat;la f%e34,

dr @etmes' i n 1972, glsedia$eb eked; t i ) 6llu4 twiagb rrnd

bead @L&ll1tA~1 66l~m%daf@ ef 8emtP0 phm bdhmX0

erbLbf t pof ;~awlhlmaX momliens ilas %he tantpem'o3lkzm

tar reduaud %a ilur tke arrracrCle A -msrUo %rarslliitton

paint$ ($5) rhcuLd be *&t~orad f i ob i ;wl lat or b e d

dsio~fion 1111 IWO~B~Q* #r af pr'oB&clDlos ham bean

*he aubjectf meter @of e h r g e nwbbr 91 tm@@tQ&tI@m. 2

~avever , no quaa$ifv$&vsr de%crrr&m%fon of f;h4 phase

d i ~ l w a a of PM w. l<rtrrX 3 I haf~ hsan -pa&&+ The

t ian uZ tlwh a ph~rraa

cPisbwja@ waa unb@r$a&n by We mthos &ad $la@ reieiulfst

w e psararmPal i n abpf er i S * Wt& ilo 1Mtg~d find aurm-

i;wre l a w & redustiart 5n 'S1* . we wed twe ex@rimll)i&P $w@wWf.Ti@a~ 90 &etamind)

%he phase dlaffraartr a i a% ar Pun%t%oa %wl&l &@farm*

Ma#&. Xn Mrae ZJLrart, the %wile% drlonaation fb gmcaduosld

by agplylrrq anaxgnstl Q Pis36 %o ra, bolanogon~aurYXj a3.iglrud

&wrap5e. Yha t i r w i t l a n pain% ww &eteet& by &wmfb~~ln$

bh6 Xlg3ht ~eatteptrd by bend EX~e.t:lxtrt;i~w 1% flre asnarp30. 3

Howev@r, aa wU1 be disouawd in ~lzapt.err XI, %hi@

ElacWl~ua dtoos nat yield r l w t l t a t f v a ~arerulta. ln %kt~;tte

@soon& m&a4, wb usdad ar wedgo s b g e d t ~ 1 t ~ t ; t b d a&atPfia

oslf. t o got the qumtlt~nGtte Brat+% on xa&~l@tias ef

IFa o f W-pegwznabsilr3syX2.d@~)-p t ~ l w yaailSw

(mQO+)(i"Sg.O) whfoh b e r~leoend arder A-$s

t*xU1810i0gg4 an4 4-rr-oolylar_jr-4'-oyrpnabiptuaaJI1 ( 8 Om) wNek h ~ n a very weak Zis8t B~T~QJ: A-8 trcZMiai tian,'

a Xuae.trbon o f Pugs9 defsi~%aP;jl~n.

92u$ie;a @writad @at ?In Bee raeam.%ada ahova b ~ f

e.troa@y poxax zna~owznBsa h w e Xed 40 fws loagrwfmt

bioewexicsa, Virtr, rac8n~raoe- rand eeaobio il pox;$-

morphissr.9 Ekere phanwm sresarlt frm rctubtb

ohtnngrs tofsliw p2me in Ch.c bilwqr stmaturae o f appluh

aoapounbar %he BiXrryar sa W a w %use &opaM# up5a the

atutw2. bfapoat0ion of WrPaua digelxac gllrosagtar in a s

R \ o ~ Q ~ u ~ R * . MrrSLv&t& by ahanre r@@u30eb we uMeraiPahc

axpsrirn~)n%a2 inVefsF28d+,tom on var.t@us p b ~ L ~ l a 1 . pmper"

Biso of aeotsrasal ~rmarslbuar~llf mrPb$a%eb li*4aB ~ryra tulUno

ampouMmt aw,f 8 f %hem gs@ressaing ~ ~ t ~ " ~ l l g l y ~9oXW2 an0

proups$ with bulky IwMea]. nad&yf ar maW0iry &~b&?&-

twntat.

9,n ahrx;t%ar XX T, we deepoz&%Fbe Xrmy fmsar8igaMona

mar ti& tthe~axal BVO~U%IC)~ Q$ hyar ngercingt~,a in

snec t i e a phof.e@a a i +nuaUEQlliytx@n$3-3 '-a(ray3.-4 *-( I.**-

-oyaactbexlabyZoxy)be3ama tra ( ~ P - B )(sea fPg.2 i ~ r

sltrw@hszsl formla), * b i z xxitro a d o w @ (~bm),

mReOOBB (csbtaincrb 'by reglooiw i@*kal a a t u l group

. .

C BOOA

-

-

81.9 82 .I 82.3 82.5 82.7

TAN OC

FIGURE 1

Variation of TAN with b y / d x for CBOOA.

of MRQ19IFI by ths btrUrter mfltre~x) aeow), aUFRgOBl11

(obGaPizrsd by xrvsrrsing ayasc end arllrgl md @wpa i n

WWcncll%), WHaQBrm ( & t ~ i n e & by E'ephcSng the opno

@ad group af W W a B wA% a brcwJPae @%car)

0 0 1 1 ) . Ofur"

aauaf@rx tn8icaee several sOriUn,, diibismnoeer, i n We

whiah the 65paSa oamarnfc ab %lo@ llnkraw grlreary6 eppoge

that s f $ha terr8imI O O ~ S P E (5~m~n0 ( w n1-tao3 woup,

axhibiO biby(t?r tlprpewe ( 3 1.6.L L $hi3

t o

t@@g~#ratrure. Xa a11 th@w @awe*, %he lager epigsafw

Snosk?as~dl snarplau Ly a@ tbe tawmywarlatwe l e lwmad %la ?flg-3)

%ha Praratia A pbroas Ploro irrtnc~tt1tinla1y. 18 PWBB L*

s x h f b i t a @ m a l L J#& i n Layler swabrmg (f%* 4 )

at '? ci 15*. 2hls aumrrponds to an Jtla - .&&

t~aanraft ion wcroardlnkl, t o D ~ P S X P C I O P ~ U O ~ B ~ O L L ' ( ~ f a t P ~ a a e ~ d

by the Bwdoaur 4;.:rhxlp.' 1IQPWUBB a@wobl~dk$, ina u R i ~ h

the dlgCtlc XPQIQBRQB O . f @he @&%X @1OW$,ki &bra &I-11

pcas'klUa1 f @ tbt e f t&@ h&mP oyanu w.L9tiiPr btpv@

rrx@%llar bllayer apcn~bwer (L1.3A) and. shw very wersk

~ h s l r m & dlr~Warrac~1, Xlncsrrci rerultsi aucs &Saoweoed Zn

of a modal i ~ z whitlr mu&+t4. Int@sra;alXon@ as %wean

1~ ,pair o f I X T ~ ~ ? ~ ~ C U S ~ ) ~ S $W cawiarUex& Cfkg.5). IC atin be

, ,t 4 -cyunophenyl --3'- m?thoxy - 4 - ( A -n - olkylbenzoyloxy ) benzontes

inCPMeOBB)

FIWRE 2: Structural fOmu3ae.and acronyms of the compounds studied

FI0.3: Temperature variation of the layer apaoing of 12 PlQiBB. (TBI - 9 ) i. the re lat ive tempsrature,

*B~I being the nemsrtia-iaotropio branaitian point. The arrow mark indicates !EM.

Tanperature variation of the layer apaoing of 10 PHOBB. , and A represent meaaurment a aoourate te - +O.l P an& $0.3 1 napot i reLy . An Ad-A2 transition eaours with a Jump i n the layer sgaoing a t the temp- rature oorreapordllng t~ the dauhed l i n e . The region around t h i s transition point i s shown on a magpified saale in the in se t , The arrow mrk inUi0at.t.s the A-tt t r a m i t ion polnt .

) mleo~rTae

porsaas aP&mrp iatesarot;laa e m s w when O~OUIUO

oagan oterkap (fig.%). (XR Ph5 albz! baddl. bha dApolc*r

ind;araatSon b e w e n t h e p6Xkw aaar*md &zolqg ~f om moXmtaTo

a& cua satar dipst@ 03 a ae&&boudz%g molsouX@ (fig.!%)

i n nipm~, a~ rr~~eomp1 smear mpa~slvo.

axPd thb intwoat5oa enerm kypllrul ba exgeated Ca b. lowar

when tlaa morrhpplw t&w phaab mixsc tihe p d b r end@

f i g . xhie ladtar t o the dlfferanacea i n the blltqror

spaainas ad4 t%air %Xmrsd dapsn$lexmcrc 8)hm by %he

dwe tyl~~~lls ~f i t~01~aulte~. h Z L f i ~ t ~ . i n a9Bm88 m a ~traihs

araaar~iea ci oaqownnd@, %he i@s~aet&edn i r e aondirred t o

on6 e M cP tho ssalaavle ewnd Oh@ r?ma&xo 1s rerfbae

e . Ap th $e&ty(o.o%uu'* fli rained, *or 1~3alCPl0tw~

wJ* rs*&nrXwplw ngas liha P O ~ L F ~ I C end@ up

b#nUe $a PtJlre up floe aoafigumbion wdtih bvrrrJklpp&nrg

of w a m u o cros~u. %%&@ lo oowe%ue~@a fPlrlar

relativeIg we& in$ewole@uXa Ja.t;emaPSsm fa $&eee

e x b e a w e of %he rr*ssnaa of bukkg Satemf

sxaQbyl 0;F aaf)laxg $FWg* A@ a taar&t%Q, bba &%Y'Qx

eakiaaing daorea8son wi%ls inarmme @1! trraoprar?rfur@.

aXbFIrOBsgll ooar~ouxldca exlhibll t 8toaoXa:pm e3sreaCf @a.

Unli'nsr ooee$~eu~@ wltih~ut wi3np ifaf@ral subaXitus&@, 10.1 1

rBB aartpaundlrs axklMt aew&Borslb^lr tki%-L

Sohemxtio diagrams Rhowing t h e aiapoait ion of varioue dipolar groups of a pair o f (a) nCPIUIBB, (b) nPMCBB molecules with an overlap of the aromatia aorss, and ( 0 ) a pair of nPMCBB molecules with an overlap aP t h e polar end groupe.

k6 we have aeea i n Wibhio pretfaur iiarrkqg;raph,

seala 0% the ampotmBa m~%&t;iaa@d aeatliex ahow Large

thearmad doa%mticm of: the blhystr ~po%fwre while

other@ rrhaw ven% %%a~ml bepexrlicsnoe. ln W a r to nee

the affeot a f @u(IB Qn-ea fn tBle bi'kgtyw E~$XUO%U~UTO

en the4 dialsotrxlo progrxUes, ws heroe a3co maartden

dialea trio e tud iea (bcah @st;ax%iia lsuzd g i i agcrza ion @Owl lsre

Up, OQ f f mi%) On @QoM O% %he@* %he ~CQQI~%*B @Ed

pre~enan$sd in ahpz~1ter XI. me a i c ~ 3 m o 0 r i ~ yrcg9rat;icbs

of the Qmpatmnd~ are in esnfworm&ty wi%h SLe mdeZ

8.mazPb.d in tM grevlsue pcar~&gr&@b. b asps a t t h e

nPM83BB aPnd WHmB ooasgarxn;la, the d.laLsaWlo gntmror9sopy

(AS * t,, - e,) lwer O~@psra%burods, i n .b;txs @mat;ta A phwb (fkg2.6).

&ah o %evcpso,sl am be sxpaaQlab. even an %he bnrh 0%

thn (J4el@otrla %aoxr of scd~nrxdials dlve ta Ea&tS. wn&

~otiar" f f We nee dZpoXe of the aa&eeulr mhl,

lu, wpragria21~ m&e wk% h bhta Z a g ax&. b W-It

bn(3 nPmB oo~pc~und~a, Were i r &a &&dikiru3& cfmtxibu-

$ion %o the zwvetr8aP of ~t d t m "ti$ wia%Zt;i~lh af %he

biXryezl stflleturm. Rcr we MVB aeen #a11@1~, w i t &

4.4 12 PMCBB

4.2~

E

3.0

3.6

~~. A€

- 0 . 4 A

,,~. ,*.-- . - . . I . L. I . . I _; i - - i 1-__t i 1

96 72 48 24 0 Tk41-T

FIG .6: Temperature variati one of the low frequency d e l e otr ic Constants (upper part) and the dieleatrlc anisotropy (lower art) of 1 2 PRCBB measured a t 1598 Hz. TN1 - T is the re lat ive temperature, TNI being the N-I transition t a p e - rature. The arrow mark indicates TM.

viii

He also peatent i n Ubg.0ar SV* $hs Url6ralxia

diegernion ssFudfae on @ante a f M e ubarr igenoionard

ooapoun$ta. Ths 4iSiweaQea in fl"ne biloyer s O ~ u 0 t u s e

between a;r"Ws(;lm and aQPMo@B wpl ~(bfl@@bbB la We

rrnZgtxakion prscemge arso. Ifk;ur: Lmtamct, in 11 PB@aS

l o which t h e Edligolr raormueatg sf $ho eeler wrrupar opypoea

%hat or me, tcisrnain~l wma group, *isl ufi peak &.- w/th inorrPa8o cf trsmlcr,Wr% (P&.?) Irhowh orre ~ @ ~ l a

n o ~ m l l y arpaati a t ~ ~ a g f w~ir~kvt~lb Wuat ioa i n %hi@ 1irW

cr~; Ohfit ter;ig@radurro i r e Ssrc~rweod. %%is L# arfgoia. a

oonar%y\psnce of the frer&li$g QQI the bllsrges mfrPLature

o f the aormgoW cslxrb thae conmre.aexant isl,&sulecBpa*nt in W e

eifeircscsEivtoiar dipate atm@nf ger mloa~lla at% highbr f~1gt4-

rctlkrsrtr of %ha ambat9 0 A plu~16. men 13% 11 (TE'HMBB

and ire a;PMsE)B%, i n whfoh the dipoxe aoraarasr si the

estes wouya are aUmerB pxralXe% t e mdpO e i t h e femfna1

caxii)no group, tka, pair@ rae rskir~wn i n iig.5a B r a up oat

hX&&er bo188parat;umelfre due %Q we& ixntwsoleou2ax fzrtexaaffem.

Frequency depend enae o f c:: at various temperature a (ahown a&ai.net the symbols) i n the meot ic A phase of 11 PMeOCBB.

m d *he peak of r't, Bu gxaaUually @is sea@ Lave3

@% &I tS.p*~aful.Y* Zn&OF~biff(%Lf, th, p*tP f0XRhe

tlon o f 1 $ PmQBB m k o w h a wi%h a98 ~mrhppj.1)4E

aerr th. polar rab* n ru lbo Ln a b x W *.l&xation oi

cA w i l & e Wotd aaxlmm at a pasir$frpuhrl l e w freurs6aoy

of c3 6 !MI gox this r e 3 ~ ~ S l a m (ii6.Lit). &pawnfiLy

in evroh a stmofurrs, Oh+ gaXr #aor&erdrta a@ ar

orauad %Be bryg

UarsrZly SD We ~b ld~ l r la phtP~(l. tho eIbet.Fraal

aouldmaMrl rp whloh *&a*@ due '60 iaafer inpu*.f$i*o,

Lo ~reabiw i n dlrao4fm yi3ars2t*r .ts a* bfrcr@$@r

(0,,3 l o b Web gergmd;lr~u3nrrr a0 She klLrrrPtar

On ?ha aQlhar b r r d d a, < a& 1st th@ ar*tafia A gl3lulra

od me necSio Sng*rr $tian i n a dbwlslosrr prxpdiaularr to

4ih.r. " msUex rr0lldjna hrrro o k a ~ l y ohm *hat tho

@o&zll9ur#fk'Ui*1f &ll&lB~&~@gl A 8 i a i z ~ n ~ l r d bg QhiB

rhm% mger arder &n jr.a aedt~m.'~ 18% ~ I U P ~ & W L W , O M I ~ ~

bg Mmw-Aourwl e t br*. 4*ooaa6ated &hat

trampoxS gmg*xUre, g.harw difhren4ty is th. bi l~4~rer

Cole-Cole p l a t .for E, r s h x n t i o n in the oaae

of 11 PNeQCBE

am3 moaaloJer ssglrcblaa~ truSlfe are 24xa4

rosiutfans i n fhs Mlnyer~ rrPruc.hxrea i n tha amo$i8 A

phaaa axhibtblted by f h . oonpowdrs anelntiomd ear3iex, wr wndaartocir nwrasuranlrrr2e o f gh@ .grinaipaEra2 corn6uoft-

v i t i s s OE Wa~la a01~pe~mdb~ ahna reaaLta rrrrr pmsan.te6

&a onuopter t.

;In amt of tb ooo9oouade aBvi&kad by us, tha

ecnduoflv2ay anleotxopy ( n u r cr,, - ~01) &~McIB:~@ I%@

beoo&n& nag3s~blvcs 8% r * o m @ avez vaperarfarsa, Ew

a@ the tmnsrsabure La low~?ed wrrarclr ZAtO b-"~ We crortla over bsog~ratwe T.Lalire SO Tar tnoreoaes

An tb koo;trlerr 11 PWaWH3, I f C?PMeGBB anb 11 PW.QE1rE3B.

%his trend 10 Lh@ acme (I\@ t l ra t a f A%Aa %be hats$ ail

M f~ranltlcloa 00 2 ~ s r ~ l eowoundr. On* womM wurrlly

azpwt jllet i f AHgA La sffltaXl, t&e aplea%t;to Uler @ h a t

saws orddc build@ up frr above, md ?$p.ccs the

ax@$# over aRould aoaur An .tihe neoaabia @a@* st a

himr $mpsrartuae xliketive .to (Ea. we Mve inhw-

prehs% %he paveme fmrd i n teap* of "L Bemiation

prwerar dw ts Zayartw i n the rraoabla A phatlis. whlck

trs~ultrts in a loworiw 05 a,,. 2h. mo'billty due $0 SEB, prraooatlon pso~ws is d d 2 , **re 4 i a ~ l s

layer thloEeaass, whiah &@#@US*& for t h e obrsexved tixen8.

.t;swemsianrm rrariaM;tone cd $he bxor wpan#lxia,a,

aielcrcllrlc yroparfSaaa [bat& *a%a.bia * an@ dirmrsicuz

~2;ud~ers up t;o 15 m5) $ad oorx~usthi*&a,sas bar aevwadJ,

Qonpasiti~sor tae %wo tti-y ey@t@l~a~, diaab wiah o l y

g o h s camponanlr 8Jrkaibfl;Puw a parural b&l&grarr [A&)

saenpsotia B ghgae an& a week% polar neatokltiagrsa. Both

tha ayatem ~ ~ x h i b i d 8 rraaximaks ( i J" t8 iaa t l~ ka4uabd

smcact;ia A pMwel and ka we31 d e i f W B rPrfnimurrr in the

&-M BC~TTI'I~SQI~ b o ~ M acry . 'fie mxlnrwo cwaw@ Scrr

~pp~iocilrua.t;erJg Wsslca psx aoaC aE the L ( ~ B P I ) J ~ o ~ ~ ) T ~ ~ B and

%he rnirriow olnrucn for er aomporltlon rl&h Pn %I%@ irlp;hSg

@oral? Q OlSrgonLsnt *

&#I ti?@ dy@%d$W3 1&~11106#%ie~.kEI($ W(BD (1) p ' - ~ t r o

gher;)tk-pn-oc%~~axyb~~a.ewt@ (WrOoB) with (2-l;ydruxy)-

p-afhoxyttr;dn%yI4?can@-p *-)DiutgrXmiUr?s, (oa-ma) C ssr f i~ ; .~ for phara d l s ~ a a ) ~ ( Z i ) p'-ri-a~) .t;j"laxy-p

o,gr?aobigr:her;yl (8 Om) ~ & % h Q - ~ u % Q x ~ ~ & I ~ ~ & - ( @ ' - ~ @ u ~ $ % @ x ~ ) -

Fiea:.;o:a,klp {(o.u~]. 2he @riSmw in dha: g b m b~u,uxrd&rjf

&!31:2R~af@~ that Lh& ~ E O P % ~ ~ ; L I bllajler OP &he polar ao@+QW&

i a p sa;t~uo .$;urally dncemg&a$Ae w i tih titao eacmuhyes ~t llerau-

teristi~ EIP %be &Mae@& A pSuaa6. WO ~) l tad i~@ e t t w Chaiof

Bhs sxttsotle A-mat2 a brwxe819lon. S& a trm&y ~ & E B C

ar&e~: far rsfrttiaraxi~ Iglr~g neicnr %he &axhunt a%" 21na A-ES

tramattion boua8ar.y whALa S t ID &Pgl02i!t, ~f #@@@ad ~ x t l o r

Mole percent of NPOOB

FIfJ.98 Phraw dinr:rmi of aixturejn of NPWB w i t h OH-EBBA. K Stande f ~ r ccr)st%llLne phase.

ohamador f a r c~orrpooltiesra Jglng mar tho nrlrr;lnrar.

;RE@ t o %be grsoanoe al %ha kaWrer1 hyBro*yX @@up I n

O % m A whiob iamereaee 62ra SRtsmroli4toulLar crlpgarrraMans,

Chs rwlaauljrur inter~toUaar srepenaible for the in&uaed

rwa@la A @reare a m aush wgoJresr i t 3 eyseCea K %hm fn

agar%- XZ. Zn rryretarr t, t h r e l e a aanslderc9ble

tkelrwl 61;xpanrslcon ~tll th %war spruning, $he, axpbknrrleua

uorbff2ad@n*lt ateakainbr~g a arortSsua mlue fC@r %he ooa~post*

%&@a aor"xe~pondiag Bo bhe rmisimua i n %he ArSR boun4ary

(ii6.00). But auoh a trond i s not ~ t w y Oawplauoua ta

ayotaaet X X, We aattribuhal thfra bJfPex@noe t o the dSltfrsront

atraar?;trk@ a$? %fie iatc)wnslaaaruPcrr intexdlaaboar i n %ha twa

am%arnrs, X t *pawe w e l 1 er~tebli.Md ah@% ahas$@ trpaneier

asa;glex Zqrm%&on butwsea tbe crtr~~?lg pa3m an% weakly

grplarc raolaauksr plays ibla &wpor%unt par% in &*in& rise

to me la4uaod eneotl t A phasre* @oape%LMosr betvaen

tha $wa m a e aE Saterrselctaare,rlorl oa.bjp8~:~111%1 e a a o a i r

S a m brlrwwn the no%@m\E#~ 838 e bron&y galfar arw$~oundlaiB

w d eth&r&a 9 ~ w i o f @ ~ iraWsa(s%ion* Eretween the asrl@oules

o i .la%rewly polew: am! we&Zar polar wllaauler Usbedncsre

ah# physioaL grogrcextieaa aF $ha nlxS;ur*nr. She rrrmaoeiar-

@Am Bs%wes the a w w f y p@Zcnx &¶'MI wb&Xy ~ O ~ I B I P l ~ o l s m l e ~ l

wlaiakk becoortlrn moxs efflf2eaSrc4 rQ 3lower tap0;rotum# leads

t o eev~ra2, intrxe6riDg eiffoase on Zh. dbbXeaw1~1

p ~ b p r b k ~ ~ ~ ~b the &xBure~t ( 1 ) the B%mTYfQ p o S ~ r

Mole percent of NPOOB FIO.10: The thermal expaneion coefiiaient s of the layer

spacings of mixturee o f lPOOB with OH-EBBA a t

lao;laroml.r~lo aodrgbataa rrrorra rrXfsrctiveU %a 13;91a~(rrZ-

~leilZl&%!t in the ~ S X ~ W ~ J ~ P . tcl"lm i i a %st pure oPlllp@W@ &a!

orhZ sR nntdpmrokSs3X f af waattoaej, bCPltwl~tabld n@eri@bourln&

mcolaaar~lezv mduae %he ~g$gg$$~v~ &&pole amant; ounrrL-

butin;: to Ch@ gol&rirl*tlonr. ktonrpaqutultly We r,, rislluss

nf the nixtuseno; ax@ liard~ter Man %he V ~ L ~ W @ e&dil(l~lat@d

fro@ an ecPditive laws (2) the ~hj~ltgbl Dramf@err au@pla~ka6

suta be O r ~ o t ~ d a t o Mve 61 t0l$r3i&terabJ% t;ran$veffi8)

p o h ~ ~ l r i a b f l S % y . Thtw re?afds in ;krr SrrrorrPaaa u i eA as

%A@ baisrporetuse, frs Jnwtrrre,@ 2x8 saZJ %he e;lxtcrsaesr

(3) ths dipolar carx*olatinn focCaa La &a id-rpwed A

phrtrawr, o m be axf>aabed 8 0 lowe% c ,, a1aa&xg;Ly amn

f a r oosga8lt;ioncr a las@ t o ttkr fir:,+ ordclr ,&4 trmfiitiorns

nem the MRXIXBUII~ 01 the phase bwMury. rr,, decrerneeg:

w i tlr P g w q a t TaaJ in fbeaa a@$r~jsaitlomcr, but a@ %bra

laannyeratzrre, i s lowertad i x: %I%@ 8 m c a ~ a o B plkbl~$~, %be

af fec t ( i mntioma abwa f.@ad~ % U an

c r k h%ncta that o i A85 ( I) as &.@ C B $ ~ S ku&, far

csm~~!o#itfaae alama l o Ohe anlnlaura fn me 8-t4 beur&haq,

which h & w a XL~~axly waoFLB Q P J ~ E st-& C J F P & B ~ ~ ~ Q ~ ~ . tho

nmct$.jlo ~rsletr an!!! hame %\I@ <i!Ap;i~l%ar ~orx@La%lom @a!% be

hrnp~atet& to in~rawksr tau %ha Leitri;jexuBae lowcsm8.

e,, hence daaa aprot inarsnss muc~h s35 Jmex tcanii:eratwse

FIO . l l r Dielectrio aniaotrogie s of mix%uree of HPOOB with OH-B3BBA as functions of re lat ive temperature. The numbere against the aymbols indicate mole peroeptagee of NPOOB and the arrows indioate TM.

Rw%h@~, thtbtse fnt;csr&@9feals &a@ 1Bd PI

higher m%fvsr.p;ion snesm fas Ch, reiaxaB2oxe. cZ e,, in

4he aiEthhlff0~3 @-wed 10 t h a t In puxre hl&hXg ;;iolsor

go~panrant+ fa ay.?yieataam Z, Lba aotapae3Sb;bera ~~mersgor&S*

a@ tho ainlmm gar, this A-M bw&uar tlb18 the

aanaDrvap6ia~ ornsxgy i n Bhe mmMhi* g?ia%d~~~ pwL.OB&bM @I$ PL

cr3inscs~ues;ar of tiire rscpaancP 0s4tar m$urs e f M s Oramlterun

in $hie asrere. 'the anuea89o Like ahost xmgcb! w$r+ #auld

be c,u9lts stran@, &a %he ntsmtic y !m&~ mand tM% In turn

crau3.d AbaQ So e\ Xowerirxg: &" M a &atSvaLicsn @&LW=. f n

c;y?gCew 11, i n whtah %scac.;urcsnrePa%e (Jun 01 mdd~ ovor a r i d %

EM&?@ o f %@msraatur@fn d n the in~Tu111~9 A ~fihsaa fa+ campa-

rerdtLollrr oLaae .X; c\i tire @axll@mm @f t h e jZSS bo?rraiat~-y, tRa

setivsseton o w r g y i e fts0ati f o iaasoaue crmtlnuorohlp -%a

Chls hrwper&eur% i e Ibw@rr& (fig?;. 1 1 ) .

FIQ.12: Plat 9f in SN vs . l /T i n the cam of a mixture of 63.5 male per cent of 8 OCB with '36.5 mole per cent

of 40.05, where fR l.8 the relaxation frequency oorre- epmding t o s,': peak.

Mole percent of NPOOB

Composition-dependence o f the relat ive crose w e r tempe- ratures of the conductivizies o f ,nixtiurea of KFUOB with

OX,l-i%BPk .

70(2W)5Bi3Q hats a muBex&$eQ ~ynBroq twgakive

dioXaeaw4a misr;at rapr, w i t t i the &x$uma Mv&H% vaXuadt

bahracsn DbnrPe af tb %wa @urn ~@aa;?@ll@n$a. XP pl~~r$!0~2ar,

u mltx%we r t f 85 ml+ p e r a~nt cl YP(2m)SQ with 19 aaXe

garr airria 09: /W ~ x b i b i t a r@zbg. ;tw valuae of A S , and

fur$h@r, a E ~ V Q C B ~ Z @I n 2 g ~ a o f ~ l e a@ rerJlpfa Wmgeratuse

Sc vazied, unu~ua l t ly baootgfng a&& $ m p e

ra9lwer9 (P$g,:.l4). @%on trralarj hara beas O ~ ) @ ~ ~ F I ( D F Q f a r

*he first tima. +&$AX b d i& epp@c$te t;e t h a t prodicrtsd

by Lit* m?agi@r-%islr t h a e ~ y GP the iJld@l@#trAa $hfpi.p?a~tid?~ o f

Tetnpsrature c3qenCleru;. c3 of l ow f rnqmncy d i e l e o t r i c oon~tnnto o f a mixture of €35 rnoh p e r oont aP 7p(2CN)5BC with 15 mole per cent of 7CB.

till@ @bar@& oybSt2lohDNa artlruobiurr in thie &arirl&ure. 'Be

aonduotivP%y aralstetreyy (A@) 81: bhesrcs qc~tem have bran

inv@&tig.ttotd Sex o rm&s of il~e3uwoiea frm 3013 1 % ~ t o

3u atam* 77P(2m)%a, ha ahmaes $&a Beu0nltlb abm*irr

exb higher tmprssaturrsao fcr &I& iw:iuenolse inv@sM&aL&

(i.tg.13). &&@in a ~a*ae%uenue a$ the atawelrl% o f the M l t

.%n&:lii# r p ? tile C*ot&c%k@ &&her, a* ZOuieblr t f k s ~ ~ ID"

r&lort.cso, tha Lsefluezioer cjg %ha, g,, mkmatiura itadat%& s ~ n

inareoa:e 4rr thet mwaaaurocl vatuer cf the oanbrrctlsrl0p ne a

Sunc.6Scn o f Zrs.ghlenrra y, ~ n ~ i h 5in nuxrrc;irl. nmu.a;los,

houravclr, &$& a,, jund a= at' 7@(2(3eP)SBO lnasrhhsrsla with

fc@duhney, psaut ianl lg by o l a b r l?lrlr&:,nltudt;la, which irs

agatn ?A uunrtcsyaance c r i the skmad aybolcaetio s*ttatuarar

in ths maim. Xn &&Lure@ with xlalaliva8Qly l w & e muls

frac?tiana, of 7W, the %tiarngaratux@ Fcstad&tioxw 05 %he

osn$uotlvi%y ,y.asa.trcp$rs w e gtrveraed by % m e a f thce

;t3.brcaaegt;hsa of cryboCu~pLi@ &rcru;jao w i t h mU?I.tlveSy 1w t P i t

Mole YO ii 0 100 0.04 x 85 0.03 0 60 0.23

39 0.85 A 20 1.80 T 7 C B 7 00

FIU.15: Tanpsrrzture variations of the r a t i o of acnduati- vitietp (at 3.592 Hz) in the nematic phase af the qqstene studied. The numbers apparing W d i a t e l y after the symbols are the mole proeatages cb 7P(2CN) 5BC and the next number is the mean ape o i f i c coruiuotivity ii. r 10' (ohm om)" a t 4 2 ' ~ .

9 GOB. KLP@ ting, K.6. i,rzrrc?ti%Ccn and C. i$,Gszkruz9, n h p . I i i ~ , at 321 (39BO).