mV indicating that activity coefficients approached unity. Table I shows only slight differences between procedures. Agreement between electrode measurements and classical methods were found in most of the earlier studies (3-7). TISAB prevented any interference in urinary fluoride measurements, because results with citrate buffer (superior to TISAB) were only slightly different. The results (Table I) indicate high specificity of urinary analysis using fluoride electrode. The anomaly observed by Cernik et al. (8) is probably due to the presence of some organically bound fluorine. It is difficult to duplicate exactly the composition of samples analyzed by Cernik er al. (8). Nevertheless, no fluorine unavailable for specific ion electrode measurements was found here. Similar results were found also by others (3-7); many samples were from aluminium or hydrofluoric acid industries ( 5 , 6). Further reports on anomalies similar to that observed recently (8) will be desirable for an exact explanation of lower results of urinary fluoride measured sometimes with the specific electrode.
Common interferences with fluoride electrode measurements due to the presence of calcium phosphate or aluminium in urine may easily be eliminated by TISAB (5-7). The selectivity might be improved also by simple diluting of samples with water. Highly specific citrate buffer may be used when necessary (no interference was found here even when some quantities of aluminium and phosphate were applied to the mixture of urines with citrate buffer). The results of this study indicate that the pretreatment of urines with perchloric acid before measurements with fluoride electrode should be used in unusual cases only. The results warrant direct simple use of fluoride electrode for exact determination of urinary fluoride, but the results should be checked from time to time with classical diffusion and photometric analysis for fluoride. Fluoride electrode measurements seem to be preferable when monitoring excreted fluorine is necessary. RECEIVED for review January 25, 1971. Accepted August 26, 1971.
Use of Potassium Phthalimide for Identification of Alkylene Bis Halides and Bis Sulfonates C. F. H. Allen and J. P. Glauser Rochester Institute of Technology, Rochester, N . Y . 14623
ALKnENE BIS HALIDES A N D SULFONATES, which are not Suitably identified in qualitative organic analysis by the use of potassium tetrachlorophthalimide in D M F , because of difficulty in purification ( I ) , readily form useful derivatives (imides 1) in one hour when the more accessible, unsubstituted potassium phthalimide is employed (Scheme 1). d
F
1
=
C
H
.-.. 2
2
&o
+
d-pH2)nd$o 1
I
Although the reaction is quite rapid (10-15 min) with the more reactive bis compounds, even including dibromomethane (bp 97 “C), the recommended procedure is t o reflux for one hour, except with sterically hindered compounds; the neopentyl derivative, which reacts mainly a t one end in a n hour, gives the bis phthalimide after four hours. Pentaerythritol tetrabromide, -mesylate, and 2,2,4,4-tetramethyl-1,3-bis(methanesu1fonoxy)cyclobutane fail. The first instance has been noted previously (2). This can be accounted for because this halide undergoes deep decomposition at 80-150 OC, as is shown in the mass spectrometer. 1,2,3-Trichloropropane, which is an exception, forms 2chloroallylphthalimide 2. None of the known (3) saturated dichloropropyl derivative could be isolated; under 1 was indicated in the mass spectrum of the once-recrystallized (1) C. F. H. Allen, W. R. Adams, and C. L. Myers, ANAL.CHEM., 37, 158 (1965). (2) J. H. Lamberton, Aust. J. Chem., 12, 106 (1959). (3) A. Neumann, Ber., 23, 994 (1890). 1694
allylimide. An analogous behavior has been observed earlier with the tribromide (4). The usefulness of this procedure can be extended t o the identification of diols, by the addition of a preliminary stepformation of a sulfonate ester (5); the latter is then converted to an imide by the procedure already outlined. Since most of the sulfonate esters of the diols are solids, they can serve as additional derivatives for identification. Aryl sulfonates are preferable, not only because of their higher melting points but also because mesyl esters may have some physiological activity (6). This sequence of reactions is particularly useful with the lower members of polyethylene glycols and sulfides, even if the esters are noncrystalline (7). EXPERIMENTAL Reagents. DIOLS. 1,lO-Decanediol (3641), 1,144etradecanediol (8457), 2,2 ’-oxydiethanol (2041) and triethylene glycol (P2828) were Eastman Chemicals ; 1,7-heptanediol came from Aldrich ; 1,5-pentanediol and tetraethylene glycol were Union Carbide Chemical Co. products. HALIDES.p-Toluenesulfonyl chloride ; 1pdihalides where n = 2,3,4,6 and 1,2,3-trichloropropane were Eastman prod(4) J. H. Lamberton, J. Aust. Chem., 8, 289 (1955). (5) “Organic Syntheses,” Collected Vol. 3, John Wiley and Sons, New York, N.Y., 1955, p 366. (6) P. Kotin and H. Falk, “Chemicals and Cancer,” Seminar Pro-
ceedings, 11/19/69, Environmental Health and Safety Department, Xerox Corporation, Xerox Square, Rochester, N.Y. (7) E. J. P. Fear, J. Thrower, and J. Veitch, J. Chem. Soc., 1958,
ANALYTICAL CHEMISTRY, VOL. 44, NO. 9,AUGUST 1972
1322.
Table I. New and Newly Obtained Bisphthalimides and Related Compounds X in reagent
Cpd No.
Product: Y = CaH4NOz YCH2CCl=CHz YCHzY Y(CHz)nY 5 Y(CHzhY 6 Y(CHd4Y 7 Y(CHz)jY 8 Y(CHz)sY 9 Y(CHz)?Y 10 Y(CHz)sY 11 Y(CH39Y 12 Y(CHz)ioY 13 Y(CHz)i4Y 14 YCHzC(CH3)nCHzY 15 YCHzCsHioCHzY 16 YCHzCHzOCHzCHzY 17 Y(CH2CHzO)zCHzCHzY 18 Y(CHKHz0)3CHzCH,Y Notes to table: u, new; b, X = C1; C, X = Br; d, X H4S03); h = special procedure.
MP, "C
2 3 4
=
used in this note
Lit.
102- 103 b U 226, 228 C d (3) 232-233 b, c, g c, g (10); b (11) 197-198 g c (12) 224-228 C b (13); c, h (14) 186-186.5 g b (15) 178-179 C U 127-127.5 C a 137-138 e h (16) C U 98.5-99.5 136 g d (17) 110-111 g U 235-237 e f (9) e a 280-28 1 156.5 g b (18, 19) 173-174 g (I a 101-102 I; e , X = mesyl (CHaSO3); f, X = besyl (CsHjSO3); g, X = tosyl(4-CH&
Table 11. Analyses
Empirical formula Mol wt 221 2 C1iH8C1NOsa 376 8 CziHzoNzOa 390 9 Cz3HzzNzOa 418 11 Cz 2% & 0 4 488 13 C3oH3sNz04 402 15 CzrHzzNzOa 408 17 CzzH2oNz06 452 18 Cz4Hz4Nz07 Calculated: C1, 1 6 . 0 z ; Found: 15.8%.
CPd No.
5
Calcd, 2
Found,
-
C
H
N
C
H
N
59.6 70.2 70.8 71.8 73.8 71.6 64.7 63.7
3.6 5.3 5.6 6.2 7.4 5.5 4.9 5.3
6.3 7.5 7.2 6.7 5.7 7.0 6.9 6.2
59.9 70.5 71 .O 72.1 73.6 71.3 64.7 64.0
3.8 5.3 5.7 6.6 7.5 5.5 5.1 5.3
6.3 7.4 6.9 6.4 5.4 7.0 7.0 5.9
~~
ucts; 1,7-dibromoheptane and pentaerythritol tetrabromide were Aldrich chemicals, and 1,9-n0namethylene dibromide came from Columbia Organic Chemicals. The gift of eight mestylated alkanes and the besylethane from T. M. Laakso (8) is gratefully acknowledged: 1,2-bis(methanesulfonoxy)ethane (mp 45-50'), 1,2-bis(benzenesulfonoxy)ethane (51-2 "), 1,3-bis(methanesulfonoxy)propane (41-2"), l,S-bis(methanesu1fonoxy)octane (65-6 "), 1,9-bis(methanesulfonoxy)nonane (55-7"), 2,2-dimethyl-1,3-bis(methanesulfonoxy)propane(768 "), 1,4-bis(methanesulfonoxymethyl)cyclohexane (1 54-8 "), 2,2,4,4 - tetramethyl - 1,3 - bis(methanesu1fonoxy)cyclobutane (140-2 "), pentaerythritol tetramesylate (210-12 "). Preparation of Derivatives. A mixture of 1 gram (approx. 0.005 mole) of either a bis halide o r bis sulfonate, 2 equivalents (0.7-4 grams) of potassium phthalimide, and 20 ml of dimethylformamide, is refluxed for an hour, cooled to about 100 'C, added to 50 grams of ice and 5 ml of 10% sodium hydroxide solution, and well-stirred to remove most of the phthalimide present. The product is collected o n a Buchner funnel, the solid washed with three 10-ml portions of cold water, and allowed to dry in the air overnight. The crude derivative is then dissolved in a minimum (ca. 20 ml) of ethyl alcohol o r acetic acid (if the melting point is above 175 "C), treated with Norite, and filtered hot, using a folded filter paper, and the recrystallized bis imide isolated by filtration. The yields of recrystallized products are 46-57 %; the upper figures apply to derivatives having higher melting points and lower solubility. Because alcoholic solutions of the chloroimide 2 creep badly, hexane is employed for recrystallization; any phthalimide present remains undissolved. (8) C. F. H. Allen and T. M. M. Laakso, U. S. Patent 2,816,125.
Notes. For convenience 1 ml of dibromomethane was used. A reaction time of 4 hr was required for the neopentyl derivative (9), otherwise the product was largely the imidoester. All the bis phthalimides are very soluble in chloroform. Bis-p-toluenesulfonates (tosylates). The usual preparative procedure (5) is followed but employing 0.1 mole of reactants. The product is collected on a chilled Buchner funnel, washed with three 20-ml portions of ice water, and air dried. This crude ester is now dissolved in the minimum amount of methanol (approx. 50 ml) by warming, and filtered into 50 ml of ice water. The crystalline ester which separates is then collected as above. If a purer product is needed, this material may be recrystallized from methanol, ethanol, or petroleum ether (50 ml), bp 30-60", drying the solution over 2 grams of anhydrous sodium sulfate for 15 min, and chilling to 0 "C. Most of the bis esters are already known (7,10). The properties of the bis phthalimido derivatives are collected in Table I. Eight new compounds are included (Table (9) G. S. Skinner and P. R. Wunz, J. Amer. Chem. SOC.,73, 3814 (1951). (10) E. J. Sakellarios, Helc. Chim. Acta, 29, 1675 (1946). (11) S. Gabriel, Ber., 22, 2224 (1889). (12) S . Gabriel and J. Weiner, ibid., 21, 2669 (1888). (13) B. Vassel, US. Patent 2,757,198; Chem. Absrr., 51, 20246 (1957). (14) W. Langenback, W. Woltersdorf, and H. Blacknitzke, Ber., 72, 671 (1939). (15) J. von Braun, ibid., 37, 3584 (1904). (16) R. H. F. Manske, J . Amer. Chem. SOC.,51, 1202 (1929). (17) J. von Braun, Ber., 42, 4541 (esp. 4551) (1909). (18) S. Gabriel, ibid., 38, 3413 (1905). (19) L. H. Cretcher, J. A. Koch, and W. H. Pittenger, J . Amer. Chem. SOC.,47, 1175 (1925).
ANALYTICAL CHEMISTRY, VOL. 44, NO. 9, AUGUST 1972
1695
Table 111. Related Phthalimides in Literature Cpd No. 19 20 21 22 23 24 25 26 27 28 29
Compound : Y = C&&NOz YCH?CBr=CH, YCH2CHClCHzCl YCHpCH=CHCHzY YCHpOCHpY YCHzCHpSCHzCHzY YCHzCHYCHpY YCHpCH(CH3)CHpY YCH2-CHBrCH2Y YCHpCHClCHzY YCHzCHOHCHpY YCHzCOCHpY
MP, "C
Mol wt
125-6 93 219 209.5-21 1 125 226-227 169-1 7 1 196-198 215-216 205 268
266 293 226-227 3 36 380 479 345 413 369 350 348
11). The identity of the remainder, with derivatives already recorded in the literature (Table III), was shown by comparison of melting points, mixture melting points (when the substances prepared by both methods were available), and by the use of instrumental methods. Physical Properties. The IR spectra were obtained using a Beckman IR20A and a Perkin-Elmer Model 137 instrument; the samples were prepared as pressed plates in potassium bromide or in Nujol mulls. Characteristic carbonyl stretching absorptions for the 5-membered-ring imide were found near 5.65 microns (weak) and 5.85 microns (strong). Mass spectra were obtained using a Hitachi-Perkin-Elmer RMS-4. All samples were introduced through the direct probe and volatilized in the temperature range of 80-150 "C. The analytical sample of 2-chloroallylphthalimide 2 showed m/e 221 (M, parent) 5.7%; 186 (M - C1) 35%; 160 (M - CC1=CH2) 22.9 %. A once-recrystallized specimen showed m / e 258 (molecular weight of dichloropropylphthali(20) A. E. Cashmore and H. McCombie, J . Chem. SOC.,123, 2884 (1923). (21) S. Gabriel and W.Michels, Ber., 25, 3057 (1892). (22) F. G. Mann, J. Chem. Soc., 1927,2907 (esp. 2912). (23) A. F. Fairbourne and G. W.Cowdrey, ibid., 1929, 129. (24) S. Gabriel and T. Posner, Ber., 27, 1042 (1894).
mide) 2-3 %, and less than 1 of phthalimide, in addition to the foregoing. (Phthalimide, itself, has mje 147, 104, 103, and 76). Pentaerythritol tetrabromide showed m/e 384 (M, parent ; Br = 79) 39%; 305 (M - Br) 100%; 225 (M - Br, HBr) 9.6%; 211 (M - Br,CH,Br) 18%,andmanyminorpeaks. The N M R spectra were measured on a Varian A 60 spectrometer. The chemical shifts are reported in ppm downfield from tetramethylsilane. The solvents were CDC1, and DMSO-de. 2-Chloroallylphthalimide 2; 4.53 (m, 2H, -NCH?-), 5.44 (m, 2H, =CH2), and 7.9 (m, 8H, arom.). 1,4-Diphthalimidobutane 6; 1.7 (t, 4H, insulated methylene), 3.6 (t, 2H, -NCH2CH20-), and 7.8 (m, 8H, arom.). ACKNOWLEDGMENT
We are pleased to have had the invaluable assistance of Miss T. J. Davis for some of the IR, D. Maier for the MS, T. H. Regan for some of the NMR, and D. Ketchum for the microanalyses-all of the Eastman Kodak Company Research Laboratory. RECEIVED for review January 3, 1972. Accepted April 17,
1972.
Selectivity Studies on Anion-Selective Membrane Electrodes Stig Back Department of Physiology and Biophysics, Medical Centre, C niaersity of Uppsala, Sweden
SANDBLOM,EISENMAN, AND WALKER(1) have deduced an expression for the potential of a liquid ion exchange membrane for the special case of two counter ions and strong association between ion and site in the membrane phase. This seems to correspond most nearly to the commercially available liquid membrane ion-selective electrodes. The following expression can be written for this potential: E
=
constant - (1
(
- 7)-In
al
RT F
F
+ (PQ( p+l + ps)'kt'a? ps).kl
(
In al
r =
)
p2s'kl. Ki.a? +pis*ki. Kz
(1)
(1) J. Sandblom, G. Eisenman, and J. L. Walker, Jr., J . Phys. Chem., 71, 3862 (1967). 1696
where p1, p 2 , p s , pis, and p Z s are mobilities in the membrane phase of ion 1, ion 2, the dissociated resin ion, the undissociated ion-pair of the resin ion, and counterion 2, respectively. In the external solution and membrane phase, KI and K2 are dissociation constants of ion-pairs of the exchanger ion with counterion 1 and counterion 2, respectively, and
(111
+
p s ( K ~ . p z s- Kz*pis) ps).p2s.Ki
-
(pz
+
ps).pis.K2
(2)
The selectivity ratio in the second logarithmic term of Equation 1 has been equated t o the ion-exchange equilibrium constant since it is reasonable t o assume that p s = ,uZa(1). However, in the derivation of Equations 2 and 3, the dissociation constants K1 and K? have been defined Only in terms Of concentrations of the various species in the membrane phase and
ANALYTICAL CHEMISTRY, VOL. 44, NO. 9, AUGUST 1972
