POPE AND GIBSON: ROTATORY POWERS, ETC. 2211CCXXX.-The Rotatoqy Powers of the Sulta of cl- ccnd1- Carnphor-t3-sutphonic Acid with d- and LPavine.By WILLIAM JACKSON POPE and CHARLES STANLEY GIBSON.IT has been repeatedly shown that a, knowledge of molecularrotatory power in aqueous solution renders great service in con-nexion with the resolution of externally compensated bases (oracids) by crystallisation with a powerful optically active acid (orbase); the theoretical scheme which leads to the indicated useof rotatory power determinations is too well known to requirerecapitulation (see preceding paper). A t the same time, theexperimental data on which the scheme is based are not veryextensive, and it is of importance to collect further evidence injustification of the extended use now so frequently made of deter-minations of molecular rotatory powers in aqueous solutions, Forthis reason, we have made a careful polarimetric examination ofthe d- and I-pavine d- and I-camphor-P-sulphonates, and haveappended thereto a description of a number of metallic salts of thelatter acids.d-Pavine d-Camphor-/3-subph ona t e and 1-Pavine 1-Cam phor-P-sdphonate, C,oH,,O,N,C,,,II,;O*SO,H.These salts are obtained by boiling equivalent quantities of thesilver salt of the corresponding acid with the hydrochloride of thecorresponding base in aqueous solution ; after filtration and con-centration, they are obtained crystalline, and, on recrystallisatio2212 POPE AND UIBSON : ROTATORY POWERS OF THE SALTS OF D-from hot alcohol, separate in glistening clusters of colourless,transparent prisms. They are very soluble in water or hot alcohol,less so in acetone or cold alcohol, and almost insoluble in benzeneor ether, and do not melt on heating:c'=62.67;C=62*39;0.1156 of d-salt gave 0.2656 CO, and 0.0708 H,O.0.1175 of Z-salt gave 0.2694 CO, and 0.0726 H20.H = 6.85.H = 6.93.C,,H,,O,NS requires C = 62.78 ; H = 6.86 per cent.The following det,erminations of rotatory power were made in2-dcm.tubes at 21°, water being used as the solvent:dBdA.0.1094 gram in 20 C.C.Na(o line). Hg(yelIos 1. Hg(green).a +1*3?2" 4-1'454" +1%63"[a] +125'4 +132-9 +l52'0[M]t718.7 +761.5 4-871.0lBlA.0.1142 gram in 20 C . C .Na(o line). Hg(ye11on). Hg(green).- 1 '438" - 1 *510" - 1 *733"- 125.9 - 132.2 - 151.7- 721 '5 - 757 *5 - 869.3From the above values the mean molecular rotatory powers of thesalts dBdA and ZBZA in dilute aqueous solution are calculated as[MI, +_ 720.1°, [MIHg +_ 759-5", and [MIHg +_ 870-lo.The mole-cular rotatory dispersions are for Hg(green)/Na(yellow) = 1.208, and forHg(yellow)/ Na(ye11ow) = 1.055-d-Pa vin e I-Ca?nphor-&xdph ona t e an d 1- Pa vin e d-Cam pho r-P-sulphonate, dBlA and ZBdA.These s a h were prepared and crystallised in the same way asthe two preceding ones, from which they differ but little in solu-bilities and general physical properties ; they crystallise in small,colourless needles :0.1189 dBZA gave 0.2726 CO, and 0-0716 H,O. C = 62-53 ; H = 6-74.0.1033 ZBdA ,, 0.2370 (20, ,, 0.0645 H20.C=62.57; H=6*98.CNH,,O,NS requires C = 62.78 ; H = 6.86 per cent.The following determinations of rotatory power were made in2-dcm. tubes at 20°, water being the solvent:dBlA.0'1200 gram in 20 C.C.Na Hi? HR(D line). (yellow). (green).a +1'315" +1*365" +1.540"[a] +109.6 +113-8 +128'3[MI + 628.1 + 652.1 t 735.1I ZSdA.0.1226 gram in 20 C.C.( D line). (1 ellow). (green). Na Hg Hg- 1.340" - 1 -380" - 1.580"- 109'3 -113 6 - 128'9- 626'3 - 651 '0 - 738.6The mean molecular rot'atory dispersions of the salts CEBZA andZBdA in dilute aqueous soIution are hence calculated as:[MI, +_ 627.2O9 [MI, (yel.) +, 651.5', and CMItI.4 (grell) +_ 736.8'AND L-CAMPHOR-P-SULPHONIC ACID WITH D- AND L-PAVINE.2213The molecular rotatory dispersions are for Hg(green)lNa(yellow) ==1.175, and f o r Hg(gellow)/NB(yellow] = 1.039 ; t1ieL.e values differconsiderably from the corresponding rotatory dispersions for thesalts dBdA and ZBZA, and this, as will be shown below, is to betraced to the differences in molecular rotatory dispersion betweenthe basic and the acid ions.It has been shown by Pope and Peachey (Trans., 1899, 75,1084)that the molecular rotatory powers of the basic and acidic ionsmay be calculated in the following manner from the molecularrotatory powers of the salts 6BdA and dBZA in dilute aqueoussolutions :[MI of dBdA+ [MI of dBZA=Twice [MI of dB ion.[MI of dBdA-[MI of dBZA=Twice [MI of dA ion.Applying these formulze to the values given above, the followingare obtained :Molecular rotations.Rotatory dispersions,Ka Hg Hg I H g ( P e d ITg(yellaw)/( D line). (yellow). (green). i Na(yel1ow). Na(pi1ow).&Base ion +673-6" +705*5" +803'4" 1.193 1047d-Acid ion +46*4 +54*0 +66*6 1 1'435 1-163ConsideratJon of the above table indicates that the discrepanciesbetween the rotatory dispersions of the two pairs of enantio-morphously related salts are due to the existence of considerabledifferences between the rotatory dispersions of the basic and acidicions produced from the salts in aqueous solution. Whilst theoptical behaviour of the salts in question is up to this point entirelyin accordance with what would be expected, it is at least remarkablethat the molecular rotatory power of the acidic ion is considerablysmaller t'han the value hitherto accepted; the examination of theammonium salt of d-camphor-P-sulphonic acid and of the salts whichthe latter forms with d- and I-tetrahydroquinaldine (Pope andPeachey, Trans., 1899, 75, 1085) leads to the conclusion that theacidic ion has the molecular rotatory power [MID +51-7O, whilstthe results stated above indicate that the value should be takenas [MI, +46*4@ It thus seemed important to obtain furtherexperimental data to supplement the small amount.of informationnow available concerning the rotatary powers of the &camphor-B-sulphonates, and Mr. P. V. Delahunty, M.Sc.Tech., has examinedcarefully purified samples of a number of such salts and of theparent acid; the results of his determinations are now given.d-Camphor-P-sulphonic A cid.This acid was prepared by the method described by Reychler(Bud,? SOC.chim., 1898, [iii], 19, la()), and, after separation fro2214 POPE AND GIBSON : ROTATORY POWERS OF THE SALTS OF D-the acetic acid solution, was recryst'allised repeatedly from ethylacetate ; during the crystallisation it was several times exposedover alkali hydroxide in a vacuum to free it from acetic acid, whichit retains with some tenacity. Solutions of the purified acid dissolvemagnesium freely in the cold and zinc on slight warming, but donot act on copper at the boiling point; the crystalline acid wassubsequently exposed to the air, and the following determinationsmade with two separate preparations :1.0012 required 0.15624 Na*OH for neutralisation.2.1170 required 0.33006 Na-OH for neutralisation.CloHl5O*SO3H = 90.51.C,oH,50*S03H = 90.41.2C,,Hl,0*803H,3H20 requires C,,H,,O*SO,H = 89.58.The above sample of the acid, which thus contains 90.45 per cent.of camphorsulphonic acid, gave the following results on deter-mination of rotatory power in aqueous solution in 2-dcm.tubesat 16O:Weight in 25 C.C. QD. [a],.1.1713 grams ...... +1*82" + 21 -44" + 49.7"1'0430 ,, . . . . . . + 1.65 + 21-86 -t-50.71'0431 ,, . . . . . , + 1'63 + 21.59 + 50.1The mean molecular rotatory power in the dilute aqueous solutionis thus [MI, +50-2O.Ammonium d-Camphor-P-sulphonate.This salt was prepared in the usud manner, and was obtainedas a mass of white needles; three separate prepara'tions indicated,on distillation with soda and titration with acid, the presence of7.59, 7-69, and 7.64 per cent.of ammonium, NH,, respectively, inplace of the theoretical percentage of 7.23. The cause of this slightdiscrepancy was not t'raced. The following determinations weremade in aqueous solutions at 16O, 2-dcm. tubes being used:Grams i n 25 C.C. a,. [ a l D * [ M I D .1-1726 + 1-92" + 20 46" + 50 *go1.0536 1'72 20.40 50'81.1295 1-85 2047 50.8The mean molecular rotatory power in dilute aqueous solutionis thus [MID +50*8O.Po t a ssium d-Cam p h o r-/3-suJp h ona t e .This salt was prepared in the usual manner, and when purifiedby crystallisation from alcohol, is obtained in colourless needles,which contain no solvent of crystallisation AND L-CAMPHOR-P-SULPHONTC ACID WITH D- AND L-PAVINE, 22 150-7860 gave 0.7150 K2PtC1,.The following determinations of rotatory power were made inK= 14.60.C1,H,,O,SK requires K = 14.44 per cent.aqueous solutions at 1 6 O in 2-dcm.tubes:Grams in 25 C.C. a D * [a],. [MI,.1.1190 4- 1 $4" -t. 18'32" + 49 '5"1.0956 1-61 18.37 49 -61 *0910 1 *60 18 *33 49 -5Calcium d-Gamphor-j3-sulphonate.On treating a solution of the acid with lime, precipitating theexcess of the latter with carbon dioxide, filtering, and Concentrating,the calcium salt is obtained in large, colourless prisms:1.0685 gave 0.2540 CaSO,.2'0298 lost 0.2613 at 105O.(C,oH,,0,S)2Ca,4H20 requires Ca= 6.97 ; H20 = 12-54 per cent.The following determinations were made in aqueous solutions atGrams in 26 C.C.a,. La1D. [MI,.1 '0042 -?- 1-39" + 17'30" + 49 '6"1.0184 1 -40 17-18 49.31'2048 1.65 17.12 49 '1Ca= 6.99.H20 =12*87.16O in 2-dcm. tubes :The mean molecular rotatory power in dilute aqueous solution isthus [MI, +49*3O.Barium d-Camphor-P-szclphoIznte, (CloH,50*S03)2Ba,3H20.This salt wm prepared by treating the ammonium salt -withbaryta, separating the excess of the latter in the usual way, andconcentrating the filtered solution until crystallisation occurred ;it was purified by recrystallisation from water, and finally obtainedin colourless needles. The solvent of crystallisation is only lostcompletely at 120-130°, and the anhydrous salt is hygroscopic :1-0124 gave 0.3600 BaSO,.Ba= 20.90.1.7860 lost 0.1473 at 130O. HzO=8.25.(C,,H,,04S),Ba,3H,0 requires Ba=20*98; HzO = 8.27 per cent.The following determinations were made in aqueous solutions atGrams in 25 C.C. QD. [ulD* [MID.1-1760 -I- 1 -43" + 15.30" + 49'6"10136 1 *23 15.16 49.51'0422 1.27 15-23 49 *71 6 O in 2-dcm. tubes :The mean molecular rotatory power in dilute aqueous solution isthus [MID + 49*6O2216 POPE AND GIBSON: ROTA'I'OKT POWERS OF THE SALTS OF D-Zinc d-Carnphor-~-sulphonate, (C,,H,,04S),Zn,6H20.The zinc salt, prepared by double decomposition between thebarium salt and zinc sulphate, crystallises in lustrous, six-sidedprisms, which melt at 167O:0.9052 lost 0-1540 at 130O.1.0136 gave 0.1300 ZnO. Zn=10-29.The following determinations were made in aqueous solutions atGrams in 25 C.C.a,. [a],IT,0=17.01.(C,,HI,04S),Zn,6H20 requires H,O = 17.01 ; Zn = 10.33 per cent.16O in 2-dcm. tubes:1 -0001 + 1 *24" + 15-49' 4- 49 '2"1'0130 1-26 15.55 4 9 41.0132 1.25 15.42 49'0The mean molecular rotatory power in aqueous solution is thus[MI, +49*2O.Silver d-Cam& o r-p-s ulph onat e, C1,H 150 S0,Ag.This salt, prepared by dissolving silver hydroxide in the aqueousacid, crystallises in colourless needles, and is readily soluble in waterand alcohol:1.0506 gave 0.4466 AgC1.The following determinations were made in aqueous solutions atAg = 31.97.CloHl,O,SAg requires Ag = 31-86 per cent.16O in 2-dcm. tubes:Grains in 25 C.C. a,. [alD. [ bf]D-1*0010 + 1-17" + 14.61" + 49 .5°1.0730 1 *25 14 56 49'41'1008 1-28 14-54 49.2The mean molecular rotatory power in dilute aqueous solution isthus [MI, +49*4O.I n addition to the salts described above, the cupric salt,crystallising with 5.5 molecules of water in pale blue rhombs, andt h e ferric salt, crystallising in yellowish-green leaflets, have alsobeen prepared.It is noteworthy that in the concentrations used, all the abovecompounds, with the exception of the free acid and its ammoniumsalt, give molecular rotatory powers less than [MID + 50°; this valueis notably lkss than was obtained by Pope and Peachey fromexamination of the ammonium salt.The still smaller value of[MI, +46.4O obtained for the acidic ion by the examination of thepavine salts described above possibly result from the greater degreeof molecular dilution in which the latter salts were examined; iASD J,-CAMPHC~R-,8-SULPHONIC ACID WITH D- AND L-PAVINE. 2217this connexion, it is worthy of note that Walden (Zeitsch.pihysikat.Chem., 1894, 15, 196) found that the molecular rotatory powersof the d-a-bromocamphor-n-sulphonates decreased slightly as thedilution increased in aqueous solution.d- and 1-Pauine d-Tartratea.Since externally compensated pavine cannot be resolved bycrystallisation with d-tartaric acid, owing to the formation of awell-characterised partly racemic dl-pavine d-tartrate (Goldschmiedt,Nonatsh., 1898, 19,321; Pope and Peachey, Trans., 1898, 73, 902),it appeared of interest to prepare and examine the d-tartrates ofboth d- and I-pavine.The salts were prepared by dissolvingequivalent quantities of the base and acid in aqueous alcvhol andevaporating to dryness ; the partly crystalline residues were thendissolved in dry acetone and precipitated as microcrystalline, whitepowders by the gradual addition of dry ether. Both salts absorbmoisture from the air, and are extremely soluble in water and mostorganic solvents ; they thus contrast strongly with dI-pavined-tartrate, which is stable in the air, and dissolves sparingly inwater and alcohol.d-Pavine d-Tartrat e, 2C~o'EE,04N,C4H606,6H~0.This salt readily absorbs moisture after drying in a vacuumdesiccator, and, for purposes of analysis, was exposed to the airuntil constant in weight :0-1170 gave 02401 CO, and 0.0682 H20.0.4364 lost 0.0394 at 1 0 5 O . H,O=9.03.C44H,,0,0N, requires C = 56.14 ; H = 6-86 ; H,O = 11.50 per cent.An accurate determination of the water of crystallisation couldnot be made, because decomposition sets in before the salt becomesanhydrous; the above analyses merely show that the salt is thenormal tartrate.0.2260 gram, dried at 105O, and made up to 20.0 C.C. with watera t 2 2 O , gave a, +3*56O in a 2-dcm. tube, whence [ulD +157-5O.C=55*97; H=6*52.It melts and decomposes at 156-158O :1-Pavine d-Tar t mt e, 2 C,,H,,0,W2,C4Hg06,H,0.After drying at 105O, this salt was found by the followinganalyses to retain one molecule of water of crystallisation; like thecorresponding salt of d-pavine, it, melts and decomposes at156-158' :VOL. XCVlI. 7 2218 CROSSLEY AND GITLTNQ : SYNTHESIS OE'0.1658 gave 0.3759 C02 and 0.0950 H,O. C = 61.81 ; H = 6.40.0.1694 ,) 0.3862 CO, 77 0.0968 H20. C = 62-16 ; H= 6.39.C,,H,,0,,N2 requires C = 62-10 ; H = 6-40 per cent.0.2810 gram, made up to 20.0 C.C. with water at 22O, gavea, - 4 . 2 3 O in a 2-dcm. tube, whence [aID - 150.5O.UNIVERSITY CHEMICAL LABORATORY,CAMBRIDGE