Znd. Eng. Chem. Res. 1991,30, 1669-1671
carbon atoms of each component. The reported technique predicts values of the parameters that are in a very close agreement with those calculated from experimental data. Acknowledgment We acknowledge with thanks an operating grant from the Natural Sciences and Engineering Research Council of Canada (NSERC). Nomenclature kl = constant in ( 5 ) k2 = constant in (8) n = number of experimental points N = number of carbon atoms per molecule M = molecular weight x = mole fraction Creek Letters v = kinematic viscosity, m2/s
McAllister three-body model interaction parameter = McAllister three-body model interaction parameter vM = McAllister four-body model interaction parameter YBBBA = McAllister four-body model interaction parameter u ~ = BMcAllister four-body model interaction parameter vm = YBA
Subscripts
A = component A in a binary mixture B = component B in a binary mixture Registry No. Octane, 111-65-9;decane, 124-18-5; undecane, 1120-21-4;tridecane, 629-50-5; pentadecane, 629-62-9.
Literature Cited Asfour, Abdul-Fattah A. Mutual and Intra-(Self-)Diffusion Coefficients and Viscosities of Binary Liquid Solutions at 25.00
OC.
1669
Ph.D. Thesis, University of Waterloo, Waterloo, Ontario, Canada, 1980. Asfour, Abdul-Fattah A. Dependence of Mutual Diffueivities on Composition in Regular Solutions: A Rationale for a New Equation. Znd. Eng. Chem. Process Des. Dev. 1985, 24, 1306-1308. &four, Abdul-Fattah A.; Dullien, Francis A. L. Dependence of Mutual Diffusivities on Concentration in Liquid n-Alkane Binary Mixtures at 25 O C : A Modification of the Asfour-Dullien Equation. Chem. Eng. Sci. 1986, 41, 1891-1894. Auslander, G. The Properties of Mixtures. Br. Chem. Eng. 1964,9, 610-618. Cooper, Elizabeth, F. Density and Viscosity of n-Alkane Binary Mixtures 88 a Function of at Several Temperatures. M.A.Sc. Thesis, University of Windsor, Windsor, Ontario, Canada, 1988. Dullien, Francis A. L.; Asfour, Abdul-Fattah A. Concentration Dependence of Mutual Diffusion Coefficients in Regular Binary Solutions: A New Predictive Equation. Znd. Eng. Chem. Fundam. 1985,24, 1-7. Heric, E. L. On the Viscosity of Ternary Mixtures. J. Chem. Eng. Data 1966,11,66-68. McAUister, R. A. The Viscosity of Liquid Mixtures. AIChE J. 1960, 6,427-431. Wei, I. C.; Rowley, R. L. Binary Liquid Mixture Viscosities and Densities. J. Chem. Eng. Data 1984,29, 332-335. Wei, I. C.; Rowley, R. L. A Local Composition Model for Multicomponent Liquid Mixture Shear Viscosity. 1985,40, 401-408.
*Author to whom correspondence should be addreeaed.
Abdul-Fattah A. Asfour,* Elizabeth F. Cooper Jiangning Wu Chemical Engineering Department, University of Windsor Windsor, Ontario, Canada N9B 3P4 Rouchdy R.Zahran Chemical Engineering Department, Alexandria University Alexandria, Egypt Received for review June 26, 1990 Revised manuscript received January 2, 1991 Accepted January 24,1991
Kinetic versus Thermodynamic Control in Chlorination of Imidazolidin-4-one Derivatives The monochlorination of 2,2,5,5-tetramethylimidazolidin-4-one (compound P) in chloroform at ambient temperature has been studied by use of 'H NMR and UV measurements. It has been (compound MC3) is the kinetically established that 3-chloro-2,2,5,5-tetramethylimidazolidin-4-one controlled product of this reaction. The second-order rate constant for formation of MC3 was ca. 4.2 X M-' s-l. Following formation of MC3, rearrangement occurred to produce l-chloro2,2,5,5-tetramethylimidazolidin-4-one (compound MC1). This reaction occurred slowly through a second-order process (k = 1.4 X M-' s-l ) and probably involves the formation of C1+ with subsequent reaction with P to produce MC1. This work is relevant to the formation of a new class of biocidal N-halamine compounds. Over the past decade a number of N-halamine compounds in the oxazolidinone and imidazolidinone classes have been synthesized and tested in these laboratories for use as stable biocides in aqueous solution and for hard surfaces. The experimental parameters for many of these biocides were summarized in a recent review by Worley and Williams (1988). The most recent work in these laboratories has resulted in the preparation of a new series of imidazolidinone derivatives that are inexpensive to synthesize, quite stable in water, and generally have greater biocidal efficacies than the previous compounds discussed by Worley and Williams (1988). Data concerning these new biocides have been presented recently in a communication (Tsao et al., 1990) and in an extensive research paper (Tsao et al., 1991).
The parent compound 1,3-dichloro-2,2,5,5-tetramethylimidazolidin-4-one (structure DC in Figure 1) is produced by adding 2 equiv of free chlorine in aqueous alkaline solution to 2,2,5,5-tetramethylimidazolidin-4-one (structure P in Figure 1). If only 1equiv of Clz were used, a monochloramine product should result. Chlorination of the l-position on the imidazolidinone ring to produce 1chloro-2,2,5,5-tetramethylimidazolidin-4-one (compound MC1 in Figure 1)would be expected given the presence of the two electron donating methyl substituents on the ring carbons adjacent to the l-nitrogen which should greatly stabilize the N-Cl bond (Williams and Worley, 1988). Compound MC1, which was used by Toda and co-workers (1972) as a source of amino radicals in an ESR experiment, has been isolated and shown to be biocidal and
0888-5885/91/2630-1669$02.50/0 0 1991 American Chemical Society
1670 Ind. Eng. Chem. Res., Vol. 30, No. 7, 1991
I
82
P
DC 0
A
H H 3 C k s C H 3
H 3 C z k H 3 H3C
N CI
I I
CH3
H,C
N
61
CH3
-
H
MC1
0
x
MC3
Figure 1. Structures of the molecules considered in this study.
extremely stable in aqueous solution in these laboratories (Tsao et aL, 1991). However, chlorination at the 3-position on the imidazolidinone ring to produce 3-chloro-2,2,5,5tetramethylimidazolidin-4-one(compound MC3 in Figure 1) might also be possible. It was conceivable that the monochloro compound isolated during synthesis was a mixture of MC1 and MC3. To test this hypothesis, a 'H NMR study has been conducted. It will be shown that MC3 is produced first upon reaction of 1 equiv of Nchlorosuccinimide with compound P in chloroform as a kinetically controlled product, followed by rearrangement to produce MC1 as a final thermodynamically controlled product. It should be noted that this study may be relevant to the chemistry of the well-known swimming pool biocide bromochlorodimethylhydantoin (BCDMH), for which U
H3C?~cC' H3C
NAg
I
Br BCDMH
there is some confusion about the position of Br and C1 on the ring (Williams and Worley, 1988). Experimental Methods Compound P (Figure 1)at a concentration of 0.0936 M was reacted with 1 equiv of free chlorine as supplied by N-chlorosuccinimide (NCS) in CDC13 solvent in an NMR tube. The 'H NMR spectra (Broker AM 400) were monitored as a function of time over a period of 15 weeks with tetramethylsilane as an internal standard. The intensity ratio of the amide proton signal to the signal for the 12 methyl protons was used to derive the relative concentrations of P, MC3, and MC1 during the reaction. Spectra of 0.0936 M NCS in CDC13,succinimide (S),and authentic MC1 at the same concentration were also obtained to aid in spectral assignments. In an analogous study 0.0049 M solutions of compound P and NCS in CHC13were reacted in a cuvette with the reaction kinetics followed by monitoring the absorption at 276 nm at 30-min intervals using a Cary 210 UV spectrophotometer. This study was performed over a period of 5 h. Compounds P and MC1 were prepared and purified as described previously (Tsao et al., 1991). N-Chlorosuccinimide and succinimide were purchased from Aldrich Chemical Company, Inc. (Milwaukee, WI) and Eastman Chemical Company, Inc. (Rochester,NY), respectively, and used without further purification.
I
i l
1
81
g
i ii
10.0
0.0
0.0
PPM
4.0
2.0
0.0
101)
BD
6.0
4.0
20
0.0
PPM
Figure 2. 'H NMR spectra at 298 K for the reaction of 0.0936 M concentrations of compounds P and NCS in CDCl,. (A) Compound P before addition of NCS (Bl) 0.0936 M NCS in CDCl,; (B2)0.0936 M succinimide in CDCla;(C) 335 min after mixing P and NCS; (D) 2519 h after mixing P and NCS.
Results and Discussion Figure 2 shows 'H NMR spectra for the various compounds studied in this work. Figure 2A represents the 'H NMR spectrum of compound P in CDCl, before addition of NCS. The intense singlets at 1.37 and 1.46 ppm which each integrate to 6 H probably correspond to the resonance of the methyl protons at ring positions 2 and 5, respectively. The singlets at 1.99 and 7.68 ppm, each corresponding to absorption of 1 H, may be assigned to the amine and amide protons at positions 1and 3, respectively. Figure 2B shows the 'H NMR spectra of pure NCS and succinimide (S) in CDC13. As can be seen, the sharp singlets for NCS and S at 2.93 and 2.77 ppm, respectively, refer to resonance of the four ring protons in each case, and the broad band at 8.64 ppm corresponds to the N-H proton on S. The spectrum in Figure 2C represents the reaction of NCS with compound P at a time of 335 min after mixing. At this time the signal corresponding to the amide proton of compound P at 6.99 ppm has almost vanished, while the amine proton resonance at 2.32 ppm maintains ita intensity. Likewise the signal corresponding to NCS at 2.96 ppm has declined markedly in intensity relative to the one for succinimide at 2.76 ppm. The signal at 8.99 ppm corresponds to the N proton for the succinimide being produced in the reaction. The shifts in the NH band positions which occurred immediately upon the mixing of P with NCS were not unexpected given possible changes in hydrogen bonding and proton exchange throughout the reaction. These observations indicate that the reaction shown below has proceeded to near completion.
1671
Ind. Eng. Chem. Res. 1991,30,1671-1672
P + NCS- MC3 + S (1) Using lH NMR data for eight time points between mixing and 335 min represented by the spectrum in Figure 2C, we have been able to determine the second-order rate constant for reaction 1 with a correlation coefficient of 0.990; it was 4.15 X M-’ s-l. The second-order rate constant obtained from the UV data in which equal concentrations of P and NCS in CHC13 were employed was 4.24 X M-ls-l (correlation coefficient was 0.9311, in excellent accord with the value obtained by NMR. After 6 h reaction time the amide ’H N M R signal began to reappear with a concomitant loss in intensity of the amine ‘H NMR signal corresponding to conversion of compound MC3 to compound MC1. Figure 2D shows the NMR spectrum after a total reaction time of 2519 h, which corresponds to greater than four half-lives of the rearrangement process. The spectrum is very similar to that for an equimoh mixture of authentic MC1 and S in CDCl, (resonances a t 1.37,1.49, 2.76,7.69, and 9.46 ppm). The small sharp lines at 1.64 and 1.76 ppm refer to proton absorptions for an, as yet, unidentified decomposition product. This product is not DC, which in CDC13 gives rise to resonances at 1.42 and 1.54 ppm. A fit of the N M R data for eight time points between 6 and 2519 h provided a second-order rate constant of 1.38 X M-’ s-l (R2 = 0.959) for the rearrangement. The rather low correlation coefficient can be attributed to difficulties in integration of the NH resonances which have estimated accuracies of about 95%. The second-order kinetics for the rearrangement may be indicative of a mechanism such as those shown in (2) or in (3) below. It should be noted that the MC3 + P MC1+ P (2)
is probably the correct one. A radical mechanism in CDCl, is also possible, although the enhanced rate in aqueous solution would seem to favor the ionic process. Current work in these laboratories involves kinetic studies of other similar imidazolidinone compounds containing C1 and Br. We are finding that solvent and steric effects play a critical role in the monohalogenation reactions. This work will be reported in due course.
Conclusion It can be concluded from this work that the reaction at ambient temperature of compound P with NCS in chloroform proceeds in a second-order kinetically controlled process to form compound MC3 over a period of a few hours. Then rearrangement occurs to form the thermodynamically controlled product MC1 over a period of 15 weeks. A similar rearrangement process may be possible for monohalogenation of the commercial dimethylhydantoin compound. Literature Cited Toda, T.; Mori, E.; Horiuchi, H.; Murayama, K. Studies on Stable Free Radicals. X. Photolysis of Hindered N-Chloramines. Bull. Chem. SOC.Jpn. 1972,45,1802-1806. Tsao, T. C.; Williams, D. E.; Worley, S. D. A New Disinfectant Compound. Ind. Eng. Chem. Res. 1990,29,2161-2163. Tsao, T. C.; Williams, D. E.; Worley, C. G.; Worley, S. D. Novel N-Halamine Disinfectant Compounds. Biotechnol. h o g . 1991, 7, 60-66.
Worley, S. D.; Williams, D. E. Halamine Water Disinfectanta. CRC Crit. Rev. Environ. Control 1988, 18, 133-175.
-+ -
*Author to whom correspondence should be addressed.
Ismat Naquib, Te-Chen Tsao Partha K. Sarathy, S. Davis Worley* Department of Chemistry, Auburn University Auburn, Alabama 36849
MC3 P C1+ MC1 (3) rearrangement process occurs much more rapidly in aqueous solution than in chloroform; MC3 cannot be isolated or identified from the reaction in aqueous solution. This would imply that the ionic mechanism shown in (3)
Received for review January 22, 1991 Revised manuscript received April 29, 1991 Accepted May 8,1991
CORRESPONDENCE Comments on “Prediction of High-pressure Vapor-Liquid Equilibria Using the Soave-Redlich-Kwong Group Contribution Method” et al. (1988): Step 1. Derive the expression for gE(Hs) from eq 9 of Kurihara et al. (1987) by setting SE = 0, Ve = 0, and u = cxjui Step 2. Replace the expression for g m )from step 1and the expression for gE(eq 9 of Kurihara et al. (1987)) into eq 3. Step 3. Equate (and, therefore, cancel) the following terms:
Sir: In a recent paper, Tochigi et al. (1990) have presented a Soave-R8dlich-Kwong group contribution method for prediction of high-pressure vapor-liquid equilibria. There is, however, a mathematical inconsistency in the derivation of their mixing rule as given by eq 4. The inconsistency is explained below. The term gE(Hs) is derived at the condition SE= 0, VE = 0, and therefore u = cxivi However, for the gEterm in eq 3, u is not equal to Cxiui Equation 4 ia obtained in the following manner from the expressions given by Kurihara et al. (1987) and Tochigi 0888-5886/91/2630-1671$02.60/0
T + P
RT-
b-T
(8
ln (u - T
) b
=R
T In (xxjuj ~ - T)bm)
b-T
1991 American Chemical Society
