Mitra, S M

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RAMAN EFFECT IN BORIC ACID AND IN SOME BORON COMPOUNDSBv S. M MI I'RA,Physics Laboratory, Dacca Llniversity(R,'. Wi', ,1 lot f>i'blhatiou. Nitvi'inhf't [5,I’lale 1ABSTRACT. Tlir i>apt-i tlir n ’Milts rilitaiiufl from llie aiiUif>r'b im(\sti,CLn1injis t>nR anu'iTi eflt rt in liorM' auVl and otJiri boniU-.s. hi tlic rase '>f (lie arid solntutii thefrroiieiirit'S sis, Sy,: and rin and in hir rase of I1k> .^olid p(t\\dri tin* fmiurnrN rnL"'*in addition of llu* Iwo hmad linrs a( ,vn.s and :^ 2oo rin ' i dnr to tlir vibiati(»ns of ( nil, wrrr nbseivcd, l ‘rrsittnab1\ 11uTC‘b^ n Ibc- niolrrnlr liinilh has a \vniin(drv D3/, .d'Ji(- rrsiilts obtauird in the rasr of nirthyl borair, rthvl boialr and biit\d b<»rab air also iiirliidrd in llie report.T N T K 0 1) V C T 1 O NIn contiiniatimi of our invcsliiuition-s <m llic Kiiiiian clTcct in oiyiuiic ;iiul inorganic conipouiuL ' very rcccnlly \u-sliulicd llic Raman s])cctra of boric acid and of a few l)oron coin])onnds. 'I'lie iirescnl paper gives llic report of the same.7C X I’ p: k  I ]\r b  n  t  a  l  a  r  r  a  n  r. !■ ; m  i { n  tThe substances n ere studied either in solid and hVjuid states or in solution and they were all Alerch’s or Kahlbainn’s preparation further purified in the usual way. 1'he method of illumination was virtually the same as that of Wood in the case of the luinids and the solutions. Tlie liipn'd for the solution) wasput in the inner tube placed inside the outer jacket of the Wood's tiil)e. The whole was clamped ui-right and a vertical mercury arc lamp was placed alongside, so that the light scattered at right angles emerged along the axis of the vertical tube. The scattered beam was totally reflected by a total reflection prism on to the slit of the spectrograph thereby making the maximum possible illuniina- ti.m. Tlie .slit of the spectrograph was guarded from direct illumination by screens and practically the whole light that entered the slit was <lue t(. the scattering at right angles.10 S. M. Mitray\t the ordiiinrv temjK'/viluru cold wntcr was continnally circulated lliroiigL tlu‘ aiuuilrir and at the lii.ehei tell)J»crallire Jiot water from a jar was con-liimally inadu 1<^ i>ass by a small pTimi), two thermometers at the inlet and at tile outlet measured the teuijieralure. The continuous l)and of tlie excitinp, belli was ('111 nit I add in,e, a little fliiort'sc'eiii to this circulating. WLitciad'lumdates w ei e all measuiLd with a Hilyer travellini’ microsi'ope and the a\• d(‘n.ij,llis nf the Ib'iman hues calculated by the welbknowii formulaA -  A . with the kuowu iiiercurv lines taken as standardii nkthe ease of Sfniie nf tl]e jjlates cn])i»ei lines wen'e taken as standard.1 n the eas/'nf till'snbd pnwder the usual tec’hniijne nf the c(»mi)lunentary ('nlniii libers was uuphnad.R n 9>V b I N  I > T S CNl S S T r) N SlUtiii Alariy wairkcrs tried In invc'stieate tliis cnmpniind in solutinii])Ut the intense' (smlinuniis baud due to the llunresceuce of the substance st(»od inlheii \\a>. Ammthakrishiiaii wliile investiyatiii.e a few benou eumpoimds fruiiul nul\ oiu fieqiK'Ucy at 875 cm N' in the case of the saturated ^solution nf the acid, lii (HU‘ present investieatif>ii we also observed this enutiuLKaus band, whieh was sn strony, that it i>racticallv obliterated the faint Isanian lines, but as in the' c'ase nf i)hos]>hnii(' aeld nbsciw’ecl by Ililibeu, ' in arsenates and eh'(‘erine observed by tbe present author and in the amino acids observed by Wriyht and bcep' ’^ it was found tliat tlu* addition of K1 to the solution reimwed this band t(wi considerable extent. The results of out measmeiuents are yi ’^en in the followdny, table and in ])late I. It Avill be evident from the tabk that:wrx, A r  — .S15. ‘'^ 7-8 -  1 111we ha\e observed tlu^  folloAi iny frecineneies th e (\ase of the saturated solution of the acid.The s]X‘c1rum of tlic powdered solid shows a strony line at A v = 8Sy cm. \  the other lines found in the ease of the solutinii eould not be identified owiny to the eontiiiuoiis ])and. Tn addition to tlie aforesaid line there are two broad lines at Ai  ^ — 3105 and 3>»oo cmN^T aulK I• ,t)IIbiunaii freiiucncies in Borie Acid, H< )-B<f)HSnt)st.'uu'e 1iC in ." ‘borie Aeid sok sat m ated at 70'C1S  ^5 1 87:1 .s!i 986 wborie aciil solid 88j s 3TOS 1>*‘^ ' 3;'90 bss— strong, weak, b -broad.nii.ylil consider tlie niolcciilc nf tlie horic ncid lo Ik aiiaKn’ous lo llic j^cueral type of molcvidc prtn ided \ve liLat tlie .mon|» ( )il as a siiiiL'dc nnil.Such a molecule eaji lia\e two types of symmetry C.,, oi U;;/, aeeoidin{vas llie slnicture is ))yra]nidal or eoplauer. 'fhe symmetiit' iilaiie slrueliiie possesses fom vibrations, one totallv symmeliie vibralion which is active in kaiiiaii eifecl Inil inactive in inlra-red^ one asyiiniietrie with lespect to the plane of Llie molecule and active in infra-red but inactixe in the Itaiiian spectnuii, and two donblv degenerate vibrations which arc actixe botli in Uaman spectiimi and ni the inlia- red. In all, W'C expect three fiecjiieiicies m the case ol the cuplaiier striiclme. d'hese vi1>rations aie shS,'^7-wand oho cm," * in the case ol the boiii  ^ acid and hence tlie acid has the symmetry 1Another inleiesting fad is revealed in the table, v i the frequency J'/v, in the case of the saturated solution xvliicli is due t<> the totally symmetrit'al vi])ia' tion of the molecule lh( ])ecomes S S i n  the case of the solid. Sucli an increase has als(» been hamd by olliers in the cases of many or;nuiic and inorganic substances. As lor the vilaatioiis , 1^05 and ;;joo cm/'* obserx’ed in the c\ise t»f thc' jioxxder, they j»erhat)s owe their origm to the vilualions of 1 n il.O R  (; A N 1 C P. o  R A T p  SIn lids connection we investigated a lew f)iganic borates, llie u'sults obtained are tabulated in the folloxving table II. Tlie ligiires within the liiai^els indicate the intensities.r\VA,h IIRaman E0cct in Boric Acid and in sonic Boron Compounds UIMeUjy] Imuifr, iiUivi h'j;ilc lint v\ ]>r,i;it(o^j (())31S i\)7-j(> (lO)S54 (o){11'’US  ^- *3,.|0 (ri y;'7 (f))7.S'^  b) S09 (1} 8gi) (4) 9^ 7 U)-r/s (j)/;. (o 770 (11(61900 (2)0.S ha/2 S. M. MitraTAm.i-, II iconid.)M( U j \  I ])()t^llc. \ 1 1 (oralc.ifj/S 1050 i‘h i (j6 s 0]|ID in< in IS)11 i:i D*l1 jS( ] < 1'ID 111l^ gn 1J1 ',D" (61(8) (8)1/^ 60 (5I.J (3)2Ss82864 (8) (8)2.S36 D) ■ 'Stj8 (8) 3880 (hiU2II’Qie on) 2ign:><go in) 307<. IMU)2cjS6 (51.)Sn.]6 O'lIt might he mentioned here that the kaman speelra of a few organie borates were investigated by JoglcUar and 'i'hatte‘‘ a iew years ago and very leeently Ananthakrislimk also studied llie Kaman si)celra of metliyl and etliyl l)orates. But tliere is a great disagreement between lliein as will be evident fioni tlie table III where tile values for the mellgyl and etli> l borates obtained by Joglekar and Thatle and /Yuanthakrivshnan, together with tliose obserxed by the i>resent author are given.T aiu.h 111.IMctlivl hnratc,' Ktbvl horate.................... — -  -A i i l h n r . J cS: 'r . A i i a i i U i a . A i i t l io r .  i J T . A n a n t h a .K17I2 jO 240 242! ?73 -9 5.188.U 8 ' 840 350) 495 4 13II 557 5 3 1Ii i^ 151A ir r u A n . \ T K  ](!,)liiunaii S}H‘clra  ol _l*oric Acid*(./) Snlutioii. sul.uraif^ d at 70°(' without potassiuin iodui^  (h) Sohilif>n .siituraled at ■ witli potahKiimi indido,( c )  Solution, saturaied at with potasyiiim iodide.Raman Effect in Boric Acid and in some Boron Compounds 13III iu'iiUl.),Me tli> 1 ))orai(*. J I 1 I 1 M>I ,|1 c,A llllli M . j  T An.'iijih;, \lllJinr1iAn.mill;7 2 (. 710 7 'S 1; 7 / 7 ’’ ’' 7 5 ‘’Nt u 1 1' it )i}‘^5 1 N()(. : Ng' * ' ‘niji ''ii).:! " 1 7 ! "p ) "'17jri^S KUO 1 J"6-, 1 (/Jt.tnj l ( u )( ) ' 100-JIIJ 11J.1 ij ;  1 ; 1 11;,1JjflO111 j J"Jn1 : i.'-So1j 1 ; 1 .’8fti 11 '' ! J,; '8J700 I1 I .;i )i)i ]'»o Jj/tn1 j J i-i'' 1 -IS> 14,)h! •i.lS’o! i'1 '"'"Vr'-)>,(! i11 2 yf>3j :>,^ 7o.'(.no2Q40 :tj4o 2 <i‘, ’^975 *^075 viyy ‘^ "7S30:30vgiSf-ii\i11 3 1 1 81Wc iniglit also conskkr tlie molecules of methyl bomte ]i(OCIl..>. as analogous to the general type X Y p r o v id e d  we treat the gronji ( tCII.-j as a single unit. Such a molecule can have, as we have already mentioned, two type.s of14 S. M. Mitrasyiijinctiy C \r acrordiiiK as the structure is pyramidal or ('oplaiier, Tnthe fonner case, C - , , ’ * there should he two totall3'^  synmictric and two double deew'niatc vilaatioiis, all the four being ac'tive iii tlie Raman spectrum. These four frequencies art identified to he ajo, 521 and7j(;(mi."^ ijj tlie case of thcmelliyl Ixu'ate, which conse(|uentl\ has the vsymmetry ''C.-j,.-”  Of tlie other frequencies, ToaSajid 1 II,: cm."* are probably due to the vibrations of u jCH;; group and tlie remaining frecpiencies are to be avSeribed to the hydrogen atoms.In c(Mi('hision tlie aiitlior thanks IVof. S. . Ih/sr for his kind interest in the work and Dr. Ik X . IMitra ami J'lof. Dr J. C, ( '.liose foi tho chemiccds and the spectrograph.PnVSM-S ]yMiOIO\ToU\ ,D acca l ’mvi-xsiTv.R ]\ 1‘ E 1< !■  N C E S’ S M. Miha, “  .Sr/cHre tna? r?f/Pf7c / ’ 2, (03^); ” /cE. f. 98, 740 (1036)102, t)f)7 (1036) : 103, 343 (]o;,7jU. /Viiantlmktislinan, ‘‘ Prur. Jnd. Uad. 74J. Uun. A tnm. L'hc. Snr.,'" d'3 , j4i,S (ki.o ).* M. jMitin, " y.cii, /. J’/73's ./ ’ 93, i ]i fneri)- '' N, Wrlglit and W T^ (v, “ Natiircd' 139, 331 (7()37). f! I\r. Jngk-kar and V. riiaUr, 7 n/. /. /V/\cs.,’* 98, dq?.7 R. Anrmtliaknslinan.V fdun . Ind. Acad. St /. *’ 4A 74 (193d)

Raman Effect in Boric Acid and in Some Boron Compounds

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Raman Effect in Boric Acid and in Some Boron Compounds

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