June, 1951
-
+ EtMgI
C130z
.--) CH3CH2C"OOH (1) LiAlH, CH3CH2C1300H CH~CHZC'~HZOH (2) p I2 CH$HgC'3H20H C H ~ C H Z C ' ~ H ~(3) I Cu-Zn CHaCH?C'3H~I CHaCH?C"Ha (4) Couple
+
___f
__f
NOTES
2943
always lower than in ~ o l u t i o n . ~This negative adsorption can be attributed to the higher concentration of the common adsorbed ion in the resin phase according to (IC). For an anion exchange resin this leads to (IHr
= jl(a.4r)
(2ai
or for a cation exchange resin
Ordinary propane of almost 100% purity has a~~ = fi(aurl (2h) been prepared from acetone in 7070 yield by elec1 and 2 From trolytic reduction. This reaction may be useful (fAr fdaH~aA8) (3a) in preparing propane-2-C13 since CH3C130CH3 nMr = fa(aUeaOH8) = .fs(aH./aMa) (3b) has been prepared starting with BaC1301in 8991, yield by Grosse and W e i n h o ~ s e . ~ where a& and a M r are determined by the amount of adsorption. (3) Grosse and Weinhouse, S c i e n r e , 104, 402 (1946). In a previous study' a weak anion exchange resin U. S. BUREAU OF MINES (m-phenylenediamine-HCHO, cyanamid type) was 4800 FORBES STREET RECEIVED DECEMBER 4 , 1950 used. In the presence of a salt of the anion it was PITTSBURGH 13, PENNA. found that a t equilibrium the amount of adsorption (exchange capacity of the anion in m. es./g.) Study on the Relation between $JHof Ion Ex- was determined by the product of the activities of change Resin Phase and the Composition of the hydrogen ion and anion in solution, i.e., (3a) Solution at Equilibrium is obeyed. For the adsorption of acetate ion in the presence RY MASATAKE HONDA or absence of 0,002, 0.02 or 0.2 N sodium acetate, An essential investigation in ion exchange re- the relation between p H - log aacetate in the soluactions is a study of the activities of the ions ad- tion and the amount of adsorption in the range sorbed by the ion exchange resin. In this work the 0.2 to 3 m. eq./g. obeyed (3a). Here the value hydrogen ion activity (pH) in the resin phase was of a H s u A s / a H A s is a constant for any weak acid. determined with appropriate pH indicators which Because of the addition of sodium acetate, the were adsorbed as ions. concentration of HAS (acetic acid) can be regarded The experimental data presented in this paper as invariable. Hence, the exchange capacity for as well as in previous work*n2involve the following acetate ion was independent of the concentration of considerations. sodium acetate. Relation (3a) was also confirmed (1) It is assumed that the exchange reaction is for the adsorption of chloride ion in the presence or purely ionic. The interior of the resin phase is absence of 0.01 N sodium chloride and in dilute taken as a homogeneous system analogous to a zinc chloride solution in the presence of an excess solution. The equilibrium condition for exchange of zinc oxide, on the above resin and later2 on a between two ions has been frequently explained by m-phenylendiamine-HCHO resin or for Amberlite the membrane equilibrium condition, namely, that IK-4B (Rohm and Haas Co.).* It has been pointed the chemical potentials of any component in the out that the data of Kunin4 for Amberlite I R 4 R resin and liquid phases should be equal a t equi- satisfy (3a).' librium. Thus for such components as HA, *XOH, In another paper2 a semi-quantitative study was MA or HzO where A and M are monovalent anions made of the equilibrium relations between comand cations, respectively, it is true that position of solution, amount of adsorption, and PH of the resin. Colorless or faintly colored cation a m u r = aHsaAs (la) or anion exchange resins, of both weak and strong aMraoHr = aMsaoHE (Ib) types, were utilized with appropriate indicators aMraAr = aMsaAs Clc) such as sulfonephthaleins or azo dyestuffs. aH,aOE, = aHsaoHs = K , (Id) A more quantitative study is presented here. where aHr is the activity of hydrogen ion in the According to 2 and 3 the amount adsorbed at resin phase and U H ~ ,the activity in the solution, equilibrium is constant when U H ~is constant and and so on. (2) The adsorption of an acid (anion) or alkali at the same time for anion exchange we have (4a) pH, -I- PA, = constant (cation) by the resin can be considered as a neutralization reaction which takes place in the resin and for cation exchange phase. When any exchange resin has adsorbed pH, pM, = constant (4b) a definite amount of an ion at equilibrium, L e . , when the activity of the adsorbed ion is a t a The following data validate these relations if i t is definite value, the p H in the resin phase should asmumed that aHr for the resins equilibrated with take a fixed value. The presence of a small various solutions are equal when the resins have amount of neutral salt hardly influences the p H attained the same color caused by the adsorption and the salt concentration in the resin phase is of an indicator whose transition point is near am.
-
!1) M. Honda, J . Chem. SOC.Japan, 71, 183, 406 (1950); Kagaku no By6iki ( J . Japan. Chem ), Extra Ed. No. 1, 19 (May, 1949); cf. C. A , , 44. 6 7 5 3 ~(1950). (2) M.Honda, J . Chrm. SOC.Jaqan, 71. 440 (1950). (8) 0. Samuelson, Ph.D. Dissertation. Horsel, Sweden, 1846
Experimental Each set of experiments was performed simultaneously a t room temperature (20 to 2 5 O ) . $Ha was measured po(4) R. Kunin and R J Myers, THISJOURNAL, 69, 2874 (1947).
N OTF s
3944
ltri tionietiically (yuinhydroiie tlectrode) or colorinietrically. Strong Cation Exchange Resin.-A colorless exchanger of polystyrolsulfonic acid3 was prepared. Commercial, colorless polystyrol was cut in pieces, treated with chlorosulfonic acid for one day a t room temperaturc, then slnwly p o u r d into watcc arid allorred to stnnd overflight. A colorless, or faiiitly yellnii , gclatinous cation cxchanger resultcd I t was cotirerted to the NaR type with CSCCLS sodium acetatc jolution, washed with water, crushed, m d screened in to 30 to 60 mesh sirc i i i water. Dry weight was measured after dchydratioii over calcium chloridc. A 5-ml. bed volume of the wet cnchanger in watcr adsorbed 0.05 ml. of 0.1% solution of dimethylaminoazobenzcne in 90% alcohol. The neutral NaR resin is yelloir but readily changes to red by washing with distillcd watcr because of slight hydrolysi5 of adsorbed sodium ion. Five nil. of resin and 20 ml. of sodium chloridc sol~itionwere bottled in a flask. The color was adjusted to the pink orange transition point of the indicator by thc use of a inininiuni amount of 0.1 .V hydrochloric acid or sodium hydrosidr. This adjustment IS so delicate that there is no coiisiderable change in either or axsr. The stable condition of exchange equilibrium was obtained in a short time by shaking the flask. The pH, was then measured. Since the adsorbed indicator was not eluted by washing or by change of PH,, the above procedure and measurement could be repeatrd with the resin. The results are summarized in Table I.
EQUILIBRIUMBETWEEN AND SODIUM
Concentration of solution, ?v NaCl
pHs
@Vas
~ H S pNas
Swelling volume,< ml./g.
Analogous experiments were repeated for other cations. Metallic chloride solutions were percolated through the bed of exchanger until saturated with the metallic ion. The exchanger was then mixed with metallic d t solution. For 0.1 N solutions of Li+, Na+, NH4+, K+, Ag+ (as nitrate), e a + +and Ba++ the measured PH. values were, respectively: 4.2,4.2,4.1,4.0,3.0,3.6 and 3.0. Strong Anion Exchange Resin.-Amberlite IRA-4006,6 (Rohm & Haas Co.) was employed. It was 30 to 50 mesh in size and pale yellow in color. It was treated with 5 % sodium hydroxide and washed almost completely with carbon dioxide free distilled water. It was dried in a slow stream of carbon dioxide free air. One-tenth-gram sample of the ROH type resin, 1.5 ml. of 0.1 N hydrochloric acid, 0.5 ml. of 0.04% aqueous solution of thymol blue and 20 nil. of sodium chloride solution were mixed in stoppered bottles. Although the indicator did not diffuse in to the centers of the granules, it was completely adsorbed by the resin. For these cases the color adjustments to dark green with hydrochloric acid took a rather long time. Table I1 presents the results. Analogous experiments for other anions were performed a t concentrations of 0.1 'molar using 1 ml. of 0.02944 indicator solution per gram of resin. Thymol blue or phenol red were the indicators. The RC1 type resin was treated with 0.1 M salt solution. For 0.1 M solution (or mixture of 0.1 M solutions) of potassium fluoride; sodium chloride; potassium bromide; potassium iodide; potassium nitrate; po( 5 ) R. KuninaadF. MoGarvey, Ind. Eng. Cbem.. 41,1265 (1949). (6) The Amberlite resins were obtained through the courtesy of Mr.
I< Kunin.
TABLE II PQC'ILIERIUM BETWEEN AMBERLITE IRA-400 (RCl)"
ANI)
Snnrrw Crrr ORIDF Sncrrrxny-., CooceutrdtiRll of solution N YnCI
1 0
$11-
S.8 -
c
9 .0
0.2 1.1 2.0
8.8 6.9 8.9 6.1 3.0 9.1 4 . ii (a. 4 .n" ca. 8 . 9 The adsorbed amounts of C1- were equal to 1.5 111. eq./g. By nephelometry. 11.1
I . /
.01 . 001 , 000
tassium sulfate; sodium acetate and acetic acid; disodium hydrogen phosphate and orthophosphoric acid the measured pH. values with thymol blue indicator at a yellowish-green color were, respectively: 7.4, 7.5, 7.6, 8.2, 7.8, 7.5, 7.4 and 7.6. For phenol red indicator a t an orange color the pH, values were, respectively: 6.4, 6.5, 6.7, 7.0, 6.6, 6.5, 6.0 and 6.2. For this indicator the amount of chloride ion adsorbed was 1.6 m. eq./g. Weak Anion Exchange Resin.-Amberlite IR-IB4 (Rohm & Haas Co.) at 20 to 50 mesh and orange in color was employed. The inherent color of this exchanger made it somewhat difficult t o observe the transition point of the indicator. Two-tenths gram of resin in the ROH form was TaRLB 1 colored with 0.2 ml. of 0.02% aqueous phenol red solution or 0.6 ml. of 0.04% aqueous thymol blue and then treated SODIUM-POLYSTYROLSULFONATE~ with 20 ml. of hydrochloric acid and sodium chloride soluCHLORIDE SOLUrIONS tions. The results are summarized in Table 111.
1.0 3.6 0.P 3 ,4 9 11 0.3 3.9 0.6' 3.3 14 .I 4.3 l.lb 3.2 15 .03 4.7 1.5 3.2 17 .01 5.0 2.0 3.0 17 .003 5.5 2.5 3.0 17 .OOl G.2 3.0 3.2 The adsorbed amounts of Na* in all cases were equal to 4.4 m. eq./g. b At higher concentrations of NaCl solution the activity coefficient of single Na+ (or C1-) was used. The change of swelling volume with salt concentration will slightly influence the PHs-PNaa.
x.
T'ol. 7 3
TABLE 111 EQUILIBRIUMBETWEEN AMBERLITEIR-4B (RCl) SODIUM CHLORIDE SOLUTION Concentration of solution, N XaC1
@Hs
pels
@Ha
AND
+ fiCls
With thymol blue indicator (1.2 in. eq./g.) 1.0 8.1 0.2 8.3 0.1 7.2 1.1 8.3 .01 6.4 2.0 8.4 .ou1 5.5 3.0 8.5 ca. 4.0" ca. 8 . 7 ,000 4.7 With phenol red indicator (3.2 m. eq./g.) 1.0 6.3 0.2 6.6 0.1 5.6 1.1 ti.7 .Ol 4.7 2.0 6.7 3.0 6.7 001 3.7 ca. 3.5" ca. 6 . 7 ,000 3.2 " By nephelometry. From these experiments and others* it was noticed that pel. or pH, - pXa, the pH, was roughly equal to pHs for any exchanger in those cases where the adsorbed indicator showed the same PH in the resin as in the aqueous solution. This leads to the possible assumption that the numerical values of pC1, or pNa, are almost negligible with regard to the value of the PH,. DEPARTMENT OF CHEMISTRY FACULTY OF SCIENCE, ST.PAUL'SUNIVERSITY IKEBUKUXO, TOKYO, JAPAN RECEIVEDJULY 10, 1950
+
An Enzymatic Synthesis of sym-Bis-(N-carbobenzoxy-L-alanyl)-hydrazine BY FREDERICK w.HOLLY,JOSEPH J. CAHILL,
JR., AND
KARLFOLKERS
In an attempt to prepare N-carbobenzoxy-Lalanine hydrazide from N-carbobenzoxy-DL-alanine by application of the method described for an enzymatic synthesis of N-carbobenzoxy-r,-glutamic
