International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 Regression analyses of log k 2 against various solvent for the reaction of p-toluenesulfonyl Chloride with α-hydroxy acid(s) in the presence of pyridine R. Kavitha 1 and S. Ananthalakshmi 2* 1 Ph. D. Research Scholar, PG & Research Department of Chemistry, Urumu Dhanalakshmi College, Tiruchirappalli - 20 019, Tamil Nadu, India. 2* Associate Professor, PG & Research Department of Chemistry, Urumu Dhanalakshmi College, Tiruchirappalli - 20 019, Tamil Nadu, India. Abstract Kinetics of the reaction of p-toluenesulfonyl Chloride (TsCl) with α-hydroxy acid(s) in the presence of pyridine under equimolar conditions in various solvents has been studied by conductometric method. The rate constants were obtained by least square method. Kinetic data shows that the reaction follows second order kinetics and first order with respect to each of the reactants. In order to understand the effect of solvent on the reaction rate, the second order rate constants were subjected to simple and multiple regression analyses. Various solvent at macroscopic and microscopic levels were used. The signs of the equation co-efficient show the contribution of each parameter on the reaction rate. Keywords: Substitution kinetics, Sulfonyl ester, Solvent effects, Microscopic and macroscopic properties, Regression analysis 1. Introduction Bimolecular nucleophilic substitution (S N 2) is important in chemical synthesis, especially for interchanging functional groups and for carbon carbon bond formation (Vollhardt K.P.C & Shore N. E, 200). It is one of the most widely studied reactions in physical organic chemistry (Sason S et. al, 1992). Usually, solvent effects are superimposed onto the intrinsic reaction dynamics, which strongly affects the reactivity. So, solvent effects are mainly used to predict the rate constants in solvents and to understand the various influences that might affect reaction rates. The kinetics of the reaction of phenacyl bromide with benzoate (Krishnapillay M et al., 1983), phenoxyacetates (Krishnapillay M et al., 1983), and cinnamates (Krishnapillay M & Balasubramanian G, 198) have been reported in acetone and acetone water medium containing various amount of water. Nallu et al. extensively studied the effect of binary aqueous organic solvents on the reaction of phenacyl bromide with nitrobenzoic acid(s) in the presence of triethylamine (Nallu M et al., 2004) Kinetic studies on the reactions of TsCl with p- substituted Benzoic acids in the presence of triethylamine in aprotic solvents have been extensively studied by Ananthalakshmi and Nallu (Ananthalakshmi S & Nallu M, 2008). Vembu et al. have studied solvent effect on the reaction of TsCl with para substituted phenols and triethylamine (Vembu et al., 2013). Though many discussions of solvent effects on reaction rates of nucleophilic substitution processes have been reported, systematic regression 231
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 investigations of reaction series are relatively few. Hence, we planned to study the solvent effects of the nucleophilic substitution reaction of TsCl with α- hydroxy acid(s) in the presence of pyridine at macroscopic and microscopic level using simple and multiple regression analyses. 2. Materials and Methods 2.1 Materials p-toluenesulfonyl chloride (TsCl), Glycolic acid, Lactic acid, Mandelic acid, Pyridine and all the solvents (Analytical grade) used were purified before use by recrystallization or distillation until their physical constants (melting point / boiling point) agreed with the literature values (Vogel A. I, 198, The Merck Index, 1983, Perrin D. D & Armarego W. L. F, 1988). In order to understand the role of the solvents on the rate, correlation and regression technique was employed. Value of log k 2 was correlated with different solvent by simple and multiple regression analysis. Regression analyses were done by using SPSS statistical software. 2.2 Methods Kinetics of the reaction of p-toluenesulfonyl Chloride (TsCl) with α-hydroxy acid(s) in the presence of pyridine under equimolar conditions in various solvents has been studied by conductometric method. The progress of the reaction was followed by measuring the conductance of the reaction mixture at different time intervals. Second order rate constant (k 2 ) was obtained from the following special integrated equation which was derived from Guggenheim s method (Guggenheim E. A & Pure J. E, 19). x 2 -x 1 = k 2 C 0 [t 1 x 1 -t 2 x 2 ] k 2 C x [t 1 -t 2 ] x 1 = Conductance at time t 1 x 2 = Conductance at time t 2 x = Conductance at time t k 2 = Second order rate constant C 0 =Initial concentration of the reactant Plot of (x 2 -x 1 ) against (t 1 x 1 -t 2 x 2 ) should be a straight line. From the slope, the second order rate constant k 2 was calculated by the method of least Square analysis. Different solvent at macroscopic and microscopic levels are given in Table 1. 3. Results and Discussion Table 1 Solvent properties at macroscopic and microscopic level The second order rate constants for the reaction of tosyl chloride with α hydroxy acid(s) (X CHOHCOOH) and pyridine in aprotic and protic solvents at 30 C are determined (Kavitha R & Ananthalakshmi S, 201) In order to understand the role of the solvents on the rate, correlation technique is employed. Value of log k 2 of examined acids in aprotic and protic solvents are correlated with different solvent at microscopic and macroscopic levels using simple and multiple regression analyses. Solvent At macroscopic level At microscopic level Aprotic ε µ D ρ γ η (ε-1)/(2ε+1) E T (30) π* log k 2 (n-pr3n + MeI) Acetonitrile 3.9 3.92 0.8 28. 0.39 0.49 4.0 0.80-0.328 Acetone 20. 2.88 0.80 23. 0.30 0.49 42.4 0.20-0.82 Dimethylformamide 3.0 3.8 0.94 3. 0.802 0.480 43.8 0.880-0.222 Ethylmethylketone 18. 2.0 0.80 23.9 0.40 0.41 41.3 0.0-1.100 Dichloromethane 8.93 1.0 1.32 2.2 0.413 0.420 41.1 0.800-0.3 Chlorobenzene.3 1.0 1.10 32.9 0.3 0.3 3. 0.10-1.1 Chloroform 4.4 1.30 1.484 2. 0.3 0.344 39.1 0.0-0.88 Protic Methanol 32. 2.8 0.92 22.1 0.44 0.40. 0.00-1.88 Ethanol 24. 1.9 0.89 21.9 1.04 0.40 1.9 0.40-2.022 Propanol 20.3 1.8 0.802 20.9 1.90 0.44 0. 0.10-2.131 Isopropylalcohol 19.4 1. 0.8 23.3 2.038 0.42 48. 0.40 - Butanol 1. 1.1 0.810 24.9 2.44 0.48 0.2 0.430-2.33 Benzyl alcohol 13.1 1.0 1.04 38.8.44 0.444 0.8 0.980-1.23 232
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 ε = Dielectric constant, µ D = Dipole moment, ρ = Density, γ = Surface tension, η = Viscocity, (ε-1)/(2ε+1) = Kirkwood function, E T (30) = Dimroth Reichardt constant, π* = Polarity / Polarizability, log k 2 LJ = log k 2 (n-pr3n + MeI) = Lassau and Jungers scale solvents shows good correlation and the other shows very poor correlation. This reflects 3.1 Simple regression analyses in the r values of given set of regression equations (Kirkwood J. G, 1939, Drougard Y & Decroocq D, The log k 2 of the second order rate constants for the 199).The best fit regression equations are given in reaction of tosyl chloride with α hydroxy acid(s) [X Table 4. This proves that none of the single CH(OH)COOH] and pyridine in aprotic and properties influence the rates of the reactions (Kapadi protic solvents at 30 C are correlated with different U. R et al., 199) Rand also reveals that the existence solvent by simple regression analyses of reactive species and the activated complex in each using the following equation (Shorter J, 194., Taft solvent may not be the same (Grahain Dawber J & R. W, 1981) Ward Williams J, 1988). The reactive species, α log k 2 = log k 0 + m X hydroxy acid(s) and pyridine can exists as (a) hydrogen bonding with pyridine (b) a tight ion pair Where, X is independent variable and m is coefficient. ion with complete proton transfer or (c) solvent separated pair. Table 2 and 3 gives the result of simple regression analyses of log k 2 in aprotic and protic solvents with ε (Dielectric constant), µ D (Dipole moment), ρ (Density), γ (Surface tension), η(viscosity), (ε- 1)/(2ε+1) (Kirkwood function), E T (30) (Dimroth Reichardt constant), π* (Polarity / Polarizability), and log k 2 (n-pr3n + MeI) (Lassau and Jungers scale) respectively. The results show that only dielectric constant (ε) of aprotic solvents and dipole moment (µ D ) of protic Table 2 Simple regression of log k 2 vs solvent parameter for the reaction between TsCl and X-CH(OH)COOH-Pyridine (X = H, CH 3, C H ) (Aprotic solvents) Solvent parameter ε µ D ρ γ η (ε+1) / (2ε+1) Regression Equation log k 2 = 0.022 ε 0.22 (0.022 ε 0.33) [0.023 ε 0.00] 0.2 µ D 0.49 (0.28 µ D 0.34) [0.283 µ D 0.339] 0.2ρ + 0.8 ( 0.92ρ + 0.898) [ 0.91ρ + 0.998] 0.033 γ 0.2 (0.021 γ 0.30) [0.034 γ 0.80] 0.20 η + 0.049 (0.1 η 0.010) [0.303 η + 0.233] 3.808 (ε+1) / (2ε+1) 1.40 (4.24 (ε+1) / (2ε+1) 1.9) [3.903 (ε+1) / (2ε+1) 1.302] 233 n r s F Eqn. no. 0.931 0.128 32.2 1 (0.81) (0.2033) (13.08) 2 [0.92] [0.1424] [29.9] 3 0.893 (0.84) [0.889] 0.49 (0.33) [0.488] 0.493 (0.290) [0.4] 0.14 (0.09) [0.12] 0.44 (0.2) [0.383] 0.1 (0.202) [0.11] 0.302 (0.299) [0.328] 0.30 (0.302) [0.3293] 0.344 (0.380) [0.388] 0.28 (0.23) [0.2941] 19.94 (12.04) [18.8] 1.20 (3.343) [1.4] 1.03 (0.40) [1.44] 0.138 (0.04) [0.13] 3.40 (.48) [3.10] 4 8 9 10 11 12 13 14 1 1 1 18
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 0.09 E T (30) 3.8 E T (30) (0.090 E T (30) 3.4) [0.099 E T (30) 3.39] 3.223 π* 2.294 π* (1.898 π* 1.382) [3.331 π* 2.1] 0.99 log k 2 (LJ) + 0.94 log k 2 (LJ) (0.49 log k 2 (LJ) + 0.42) [0.21 log k 2 (LJ) + 0.910] Value in ( ) is for glycolic acid (X = CH 3 ) Value in [ ] is for mandelic acid (X = C H ) 0.841 (0.21) [0.] 0.4 (0.414) [0.3] 0.9 (0.49) [0.9] 0.1900 (0.282) [0.212] 0.2223 (0.321) [0.244] 0.2119 (0.33) [0.2384] 12.08 (.404) [10.48].482 (1.03) [.44] 8.33 (1.3) [.33] 19 20 21 22 23 24 2 2 2 Table 3 Simple regression of log k 2 vs solvent parameter for the Reaction between TsCl and X-CH(OH)COOH-Pyridine (X = H, CH 3, C H ) (Protic solvents) Solvent Regression Equation parameter log k 2 = 0.08 ε 0.204 ε (0.0 ε 2.284) [0.08 ε 1.824] 0.92 µ D 2. µ D (0.93 µ D 2.882) [8.32 µ D 14.821] 1.08 ρ + 0.00 ρ ( 0.994 ρ 0.23) [ 1.049ρ + 0.28] 0.01 γ 0.408 γ ( 0.04 γ 0.019) [ 0.049 γ + 0.14] 0.13 η 0.28 η ( 0.131 η 0.8) [ 0.134 η 0.29] 23.1 (ε+1) / (2ε+1) 11.40 (ε+1) / (20.832 (ε+1) / (2ε+1) 10.) (2ε+1) [1.33 (ε+1) / (2ε+1) 8.8] 0.1 E T (30) 9.914 E T (30) (0.1 E T (30) 10.101) [0.1 E T (30) 9.32] 0.03 π* 0.8 π* (0.01 π* 1.102) [0.041 π* 0.23] 0.04 log k 2 (LJ) 0.12 log k 2 (LJ) (0.03 log k 2 (LJ) 0.928) [0.038 log k 2 (LJ) 0.48] Value in ( ) is for glycolic acid (X = CH 3 ) Value in [ ] is for mandelic acid (X = C H ) n r s F Eqn. no. 0.83 0.2891 9.204 28 (0.829) (0.2909) (8.93) 29 [0.83] [0.283] [9.20] 30 0.92 (0.9) [0.94] 0.230 (0.218) [0.231] 0.243 (0.139) [0.148] 0.498 (0.488) [0.49] 0.484 (0.434) [0.41] 0.8 (0.882) [0.884] 0.01 (0.02) [0.018] 0.03 (0.043) [0.031] 0.1238 (0.11) [0.101] 0.111 (0.0) [0.02] 0.09 (0.12) [0.13] 0.44 (0.441) [0.400] 0.49 (0.48) [0.414] 0.219 (0.24) [0.2421] 0.21 (0.200) [0.18] 0.91 (0.88) [0.81].938 (.89) [33.28] 0.224 (0.200) [0.22] 0.20 (0.08) [0.089] 1.320 (1.249) [1.311] 1.224 (0.92) [0.840] 13.388 (13.93) [14.348] 0.001 (0.003) [0.001] 0.004 (0.00) [0.003] 31 32 33 34 3 3 3 38 39 40 41 42 43 44 4 4 4 48 49 0 1 2 3 4 Solvent parameter Table 4 Best- fit simple regression equation Regression Equation n r s F Eqn. log k 2 = no. Aprotic solvents 0.931 0.128 32.2 1 [0.92] [0.1424] [29.9] 3 Protic solvents 0.92 0.1238.938 31 (0.9) (0.11) (.89) 32 [0.94] [0.101] [33.28] 33 ε 0.022 ε 0.22 [0.023 ε 0.00] µ D 0.92 µ D 2. (0.93 µ D 2.882) [8.32 µ D 14.821] 234
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 3.2 Multiple regression Dual and Triple solvent parameter regression analyses From the simple regression analyses it is noted that the effect of solvents on reaction rate are more complex and more than one solvent parameter may influence the reactive species. So, in order to obtain a better correlation we have done dual regression analyses and triple regression analyses of log k 2 with solvent. Dual regression of log k 2 with solvent are obtained by using the following equation log k 2 = log k 0 + a 1 X 1 + a 2 X 2 Where, X 1 and X 2 are variables. The results of dual regression analyses are given in Table and. Dual regression gives better correlation than simple regression. The best fit dual regression equations are given in Table and 8 for aprotic and protic solvents respectively. From the dual regression analyses for aprotic solvents µ D along with (ε-1)/(2ε+1), π* and log k 2 (LJ), ε along with (ε-1) / (2ε+1), E T (30), π* and log k 2 (LJ), ρ along with π*, γ along with E T (30) and η along with E T (30) gives satisfactory correlation. For protic solvents µ D along with (ε- 1)/(2ε+1), E T (30), π* and log k 2 (LJ) and ε along with (ε-1)/(2ε+1) and E T (30) gives good correlation. Table Dual regression of log k 2 vs solvent parameter for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Aprotic solvents) n r s F Regression equation (log k 2 =) µ D + (ε-1)/(2ε+1) 0.98 0.112 22.32 0.41 µ D 4.20 (ε-1)/(2ε+1) + 0.93 (0.849) (0.228) (.18) (0.324 µ D 0.99 (ε-1)/(2ε+1) 0.319) [0.91] [0.1009] [32.44] [0.30 µ D.480 (ε-1)/(2ε+1) +1.399] 23 Eqn. no µ D + E T (30) 0.900 (0.849) [0.892] 0.108 (0.2288) [0.189] 8.8 (.13) [.3] 0.208 µ D + 0.02 E T (30) 1.401 (0.321 µ D 0.018 E T (30) + 0.011) [0.238 µ D + 0.019 E T (30) 1.023] 8 9 0 µ D + π* 0.9 (0.84) [0.91] 0.1028 (0.2303) [0.1293] 2.183 (.00) [18.90] 0.202 µ D + 1.4 π* 1.8 (0.284 µ D 0.14 π* 0.31) [0.218 µ D + 1.9 π* 1.2] 1 2 3 µ D + log k 2 (LJ) 0.940 (0.848) [0.92] 0.1338 (0.2290) [0.182] 1.222 (.140) [12.012] 0.194 µ D + 0.332 log k 2 (LJ) 0.00 (0.29 µ D 0.080 log k 2 (LJ) 0.3) [0.213 µ D + 0.318 log k 2 (LJ) + 0.00] 4 ε + (ε-1)/(2ε+1) 0.93 (0.31) [0.98] 0.0898 (0.231) [0.012] 3.233 (2.293) [.193] 0.038 ε 4.01 (ε-1)/(2ε+1) + 1.2 (0.013 ε + 0.981 (ε-1)/(2ε+1) 0.3) [0.042 ε 4.91 (ε-1)/(2ε+1) + 1.43] 8 9 ε + E T (30) 0.933 (0.28) [0.92] 0.141 (0.244) [0.1] 13.349 (2.20) [12.308] 0.024 ε 0.010 E T (30) +0.14 (0.013 ε + 0.014 E T (30) 0.81) [0.02 ε 0.020 E T (30) + 0.14] 0 1 2 ε + π* 0.92 (0.98) [0.90] 0.10 (0.223) [0.1310] 2.11 (3.498) [18.43] 0.01 ε + 1.28 π* 1.130 (0.022 ε 1. π* +0.902) [0.019 ε + 1.232 π* 0.91] 3 4 ε + log k 2 (LJ) 0.94 (0.80) [0.933] 0.128 (0.219) [0.10] 1.0 (3.98) [13.483] 0.018 ε + 0.203 log k 2 (LJ) 0.001 (0.02 ε 0.434 log k 2 (LJ) 0.4) [0.020 ε + 0.12 log k 2 (LJ) + 0.138] 8 ρ + (ε-1)/(2ε+1) 0. (0.2) [0.2] 0.29 (0.298) [0.329] 1.0 (2.221) [1.282] 0.2 ρ + 4.99 (ε-1)/(2ε+1) 2.228 ( 0.043 ρ + 4.34 (ε-1)/(2ε+1) 1.838) [0.20 ρ + 4.832 (ε-1)/(2ε+1) 1.918] 9 80 81 ρ + E T (30) 0.843 (0.8) [0.823] 0.211 (0.2821) [0.23] 4.893 (2.0) [4.213] 0.00 ρ + 0.098 E T (30) 3.92 ( 0.3 ρ + 0.0 E T (30) 2.294) [0.04 ρ + 0.102 E T (30) 3.908] 82 83 84 ρ + π* 0.939 0.131 14.880 0.04 ρ + 3.320 π* 1.44 8
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 ρ + log k 2 (LJ) γ + (ε-1)/(2ε+1) γ + E T (30) γ + π* γ + log k 2 (LJ) η + (ε-1)/(2ε+1) (0.3) [0.91] 0.888 (0.) [0.82] 0.80 (0.8) [0.] 0.98 (0.) [0.934] 0.4 (0.41) [0.1] 0.812 (0.493) [0.8] 0.38 (0.90) [0.1] (0.24) [0.193] 0.180 (0.2832) [0.2119] 0.2318 (0.21) [0.238] 0.1128 (0.281) [0.149] 0.248 (0.3933) [0.2] 0.2294 (0.34) [0.288] 0.248 (0.22) [0.2921] (2.93) [10.23].4 (2.0) [.804] 3.38 (3.04) [3.041] 22.233 (2.843) [13.2] 2.994 (0.421) [2.88] 3.88 (0.43) [3.23] 2.39 (3.32) [2.109] ( 0.81 ρ + 2.03 π* 0.43) [ 0.33 ρ + 3.43 π* 1.04] 0.448 ρ + 0.2 log k 2 (LJ) + 1.123 ( 0.20 ρ + 0.404 log k 2 (LJ) +1.11) [ 0.42 ρ + 0.1 log k 2 (LJ) + 1.32] 0.032 γ + 3.8 (ε-1)/(2ε+1) 2.3 (0.021 γ + 4.0 (ε-1)/(2ε+1) 2.2) [0.033 γ + 3.83 (ε-1)/(2ε+1) 2.243] 0.031 γ + 0.093 E T (30) 4.3 (0.019 γ + 0.088 E T (30) 4.14) [0.032 γ + 0.09 E T (30) 4.4] 0.002 γ + 3.130 π* 2.290 (0.00γ + 1.28π* 1.380) [0.002 γ + 3.24 π* 2.1] 0.012 γ + 0.2 log k 2 (LJ) + 0.30 (0.00 γ + 0.42 log k 2 (LJ) + 0.180) [0.012 γ + 0.1 log k 2 (LJ) + 0.13] 0.1 η + 4.43 (ε-1)/(2ε+1) 2.048 (0.281 η + 0.49 (ε-1)/(2ε+1) + 0.48) [0.1 η + 4.1(ε-1)/(2ε+1) 1.930] 8 8 88 89 90 91 92 93 94 9 9 9 98 99 100 101 102 103 104 10 η + E T (30) η + π* η + log k 2 (LJ) 0.98 (0.80) [0.93] 0. (0.414) [0.1] 0.80 (0.490) [0.81] 0.0988 (0.24) [0.129] 0.2481 (0.3938) [0.2] 0.232 (0.31) [0.213] 29. (3.42) [19.88] 3.00 (0.41) [2.89] 3.03 (0.33) [3.13] 0.83 η + 0.11 E T (30).011 (0.03 η + 0.10 E T (30) 4.9) [0.899 η + 0.120 E T (30).02] 0.04 η + 3.20 π* 2.291 ( 0.024 η + 1.91 π* 1.383) [ 0.00 η + 3.3 π* 2.18 ] 0.190 η + 0.93 log k 2 (LJ) + 0.93 (0.490 η + 0.43 log k 2 (LJ) + 0.348) [0.222 η + 0.14 log k 2 (LJ) + 0.91] 10 10 108 109 110 111 112 113 114 Value in [ ] is for X = C H Table Dual regression of log k 2 vs solvent parameter for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Protic solvents) µ D + (ε-1)/(2ε+1) µ D + E T (30) µ D + π* µ D + log k 2 (LJ) ε + (ε-1)/(2ε+1) ε + E T (30) n r s F Regression equation log k 2 = Eqn. no 0.9 (0.98) [0.9] 0.93 (0.9) [0.94] 0.9 (0.9) [0.9] 0.992 (0.9) [0.989] 0.91 (0.91) [0.93] 0.902 (0.902) [0.90] 0.1322 (0.123) [0.124] 0.1399 (0.1319) [0.13] 0.1339 (0.123) [0.128] 0.093 (0.0892) [0.108] 0.188 (0.189) [0.182] 0.223 (0.224) [0.23] 30.081 (32.443) [31.8] 2.4 (29.88) [2.84] 29.29 (31.884) [31.14] 9.941 (2.23) [44.39] 14.34 (14.30) [14.9].32 (.19) [.88] 23. µ D + 4.18 (ε-1)/(2ε+1) 12.0 (.4 µ D + 3.8 (ε-1)/(2ε+1)) 12.91 [.1 µ D + 3.924 (ε-1)/(2ε+1) 12.22].9 µ D 0.01 E T (30) 0.02 (.99 µ D 0.023 E T (30) 11.213) [.44 µ D 0.018 E T (30) 10.38].03 µ D 0.194 π* 11.09 (.990 µ D 0.19π* 11.29) [.981 µ D 0.18 π* 10.].48 µ D 0.021 log k 2 (LJ) 12.01 (.984 µ D 0.01 log k 2 (LJ) 12.32) [.31 µ D 0.02 log k 2 (LJ) 11.32] 0.108 ε 3.12 (ε-1)/(2ε+1) +13.02 (0.108 ε 3.11 (ε-1)/(2ε+1) + 13.488) [0.10 ε 3.83 (ε-1)/(2ε+1) + 13.18] 0.02 ε + 0.118 E T (30).43 (0.02 ε + 0.118 E T (30).42) [0.024 ε + 0.121 E T (30).283] 11 11 11 118 119 120 121 122 123 124 12 12 12 128 129 130 131 132 ε + π* 0.894 0.220.99 0.0 ε + 0.90 π* 2.10 133
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 ε + log k 2 (LJ) ρ + (ε-1)/(2ε+1) ρ + E T (30) ρ + π* ρ + log k 2 (LJ) γ +(ε-1)/(2ε+1) γ + E T (30) γ + π* γ + log k 2 (LJ) η + (ε-1)/(2ε+1) η + E T (30) η + π* η + log k 2 (LJ) (0.894) [0.894] 0.884 (0.884) [0.882] 0.2 (0.30) [0.32] 0.88 (0.88) [0.894] 0.3 (0.3) [0.18] 0.0 (0.0) [0.9] 0.1 (0.43) [0.43] 0.882 (0.900) [0.901] 0.1 (0.141) [0.13] 0. (0.091) [0.100] 0.4 (0.39) [0.49] 0.88 (0.88) [0.891] 0.9 (0.) [0.0] 0.4 (0.41) [0.4] (0.221) [0.28] 0.3421 (0.3422) [0.3391] 0.43 (0.44) [0.443] 0.299 (0.2801) [0.28] 0.411 (0.4114) [0.410] 0.181 (0.180) [0.1] 0.488 (0.32) [0.29] 0.288 (0.21) [0.298] 0.4981 (0.948) [0.919] 0.984 (0.18) [0.148] 0.08 (0.08) [0.00] 0.282 (0.29) [0.219] 0.388 (0.380) [0.382] 0.48 (0.484) [0.48] (.9) [.94] 3.9 (3.3) [3.498] 0.94 (0.988) [0.99].0 (.39) [.98] 1.4 (1.1) [1.94] 0.992 (0.991) [0.934] 0.910 (0.409) [0.431].2 (.41) [.4] 0.2 (0.030) [0.03] 0.493 (0.008) [0.010] 0.33 (0.1) [0.48].414 (.9) [.81] 2.12 (2.134) [2.19] 1.2 (1.219) [1.24] (0.0 ε + 0.88 π* 2.08) [0.0 ε + 0.8 π* 2.40] 0.04 ε + 0.388 log k 2 (LJ) 1.443 (0.04 ε + 0.38 log k 2 (LJ) 1.444) [0.03 ε + 0.31 log k 2 (LJ) 0.31] 4.44 ρ + 0.1 (ε-1)/(2ε+1) 32.22 (4.83 ρ + 0.2 (ε-1)/(2ε+1) 32.84) [4.80 ρ + 9.919 (ε-1)/(2ε+1) 32.184] 0.98 ρ + 0.14 E T (30) 9.248 ( 0.99 ρ + 0.14 E T (30) 9.240) [ 0.99 ρ + 0.13 E T (30) 8.98] 9.1 ρ + 4.2 π* + 4.442 ( 9.4 ρ + 4.48 π* +4.439) [ 9.8 ρ + 4.9 π* + 4.0].99ρ + 1.31 log k 2 (LJ) + 8.41 (.992 ρ + 1.29 log k 2 (LJ) + 8.44) [.94ρ + 1. log k 2 (LJ) + 8.0] 0.09 γ + 8.21 (ε-1)/(2ε+1) 29.33 ( 0.043 γ + 18.0 (ε-1)/(2ε+1) 8.42) [ 0.04 γ + 19.004 (ε-1)/(2ε+1) 8.310] 0.00 γ + 0.14 E T (30) 9.93 (0.0 γ + 0.190 E T (30) 12.29) [0.02 γ + 0.189 E T (30) 11.91] 0.089 γ + 2.81 π* 0.1 ( 0.049 γ 0.09 π* + 0.082) [ 0.04 γ 0.088 π* + 0.3] 0.0 γ + 1.1 log k 2 (LJ) + 3.382 ( 0.030 γ + 0.009 log k 2 (LJ) + 0.009) [ 0.03 γ 0.010 log k 2 (LJ) + 0.201] 0.49 η.0 (ε-1)/(2ε+1) + 2.838 ( 0.0 η 9.39 (ε-1)/(2ε+1) + 2.13) [ 0.1 η 0.999 (ε-1)/(2ε+1) + 28.30] 0.03 η + 0.1 E T (30) 9.230 ( 0.031η + 0.1 E T (30) 9.04) [ 0.033 η + 0.1 E T (30) 8.994] 0.31 η + 2.0 π* 1.32 ( 0.311 η + 2.02 π* 1.) [ 0.312 η + 2.03 π* 1.08] 0.2 η + 0.912 log k 2 (LJ) + 1.90 ( 0.29 η + 0.901 log k 2 (LJ) + 1.32) [ 0.29 η + 0.890 log k 2 (LJ) + 1.4] 134 13 13 13 138 139 140 141 142 143 144 14 14 14 148 149 10 11 12 13 14 1 1 1 18 19 10 11 12 13 14 1 1 1 18 19 10 11 12 13 14 Value in [ ] is for X = C H Table Best- fit dual regression equation for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Aprotic solvents) n r s F Regression equation (log k 2 =) µ D + (ε-1)/(2ε+1) 0.98 0.112 22.32 0.41 µ D 4.20 (ε-1)/(2ε+1) + 0.93 [0.91] [0.1009] [32.44] [0.30 µ D.480 (ε-1)/(2ε+1) +1.399] Eqn. no µ D + π* 0.9 [0.91] 0.1028 [0.1293] 2.183 [18.90] 0.202 µ D + 1.4 π* 1.8 [0.218 µ D + 1.9 π* 1.2] 1 3 µ D + log k 2 (LJ) 0.940 [0.92] 0.1338 [0.182] 1.222 [12.012] 0.194 µ D + 0.332 log k 2 (LJ) 0.00 [0.213 µ D + 0.318 log k 2 (LJ) + 0.00] 4 23
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 ε + (ε-1)/(2ε+1) 0.93 [0.98] 0.0898 [0.012] 3.233 [.193] 0.038 ε 4.01 (ε-1)/(2ε+1) + 1.2 [0.042 ε 4.91 (ε-1)/(2ε+1) + 1.43] 9 ε + E T (30) 0.933 [0.92] 0.141 [0.1] 13.349 [12.308] 0.024 ε 0.010 E T (30) +0.14 [0.02 ε 0.020 E T (30) + 0.14] 0 2 ε + π* 0.92 [0.90] 0.10 [0.1310] 2.11 [18.43] 0.01 ε + 1.28 π* 1.130 [0.019 ε + 1.232 π* 0.91] 3 ε + log k 2 (LJ) 0.94 [0.933] 0.128 [0.10] 1.0 [13.483] 0.018 ε + 0.203 log k 2 (LJ) 0.001 [0.020 ε + 0.12 log k 2 (LJ) + 0.138] 8 ρ + π* 0.939 [0.91] 0.131 [0.193] 14.880 [10.23] 0.04 ρ + 3.320 π* 1.44 [ 0.33 ρ + 3.43 π* 1.04] 8 8 γ + E T (30) 0.98 [0.934] 0.1128 [0.149] 22.233 [13.2] 0.031 γ + 0.093 E T (30) 4.3 [0.032 γ + 0.09 E T (30) 4.4] 94 9 η + E T (30) 0.98 [0.93] 0.0988 [0.129] 29. [19.88] 0.83 η + 0.11 E T (30).011 [0.899 η + 0.120 E T (30).02] 10 108 Value in [ ] is for X = C H Table 8 Best- fit dual regression equation for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Protic solvents) µ D + (ε-1)/(2ε+1) µ D + E T (30) µ D + π* µ D + log k 2 (LJ) ε + (ε-1)/(2ε+1) ε + E T (30) Value in [ ] is for X = C H n r s F Regression equation log k 2 = Eqn. no 0.9 (0.98) [0.9] 0.93 (0.9) [0.94] 0.9 (0.9) [0.9] 0.992 (0.9) [0.989] 0.91 (0.91) [0.93] 0.902 (0.902) [0.90] 0.1322 (0.123) [0.124] 0.1399 (0.1319) [0.13] 0.1339 (0.123) [0.128] 0.093 (0.0892) [0.108] 0.188 (0.189) [0.182] 0.223 (0.224) [0.23] 30.081 (32.443) [31.8] 2.4 (29.88) [2.84] 29.29 (31.884) [31.14] 9.941 (2.23) [44.39] 14.34 (14.30) [14.9].32 (.19) [.88]. µ D + 4.18 (ε-1)/(2ε+1) 12.0 (.4 µ D + 3.8 (ε-1)/(2ε+1)) 12.91 [.1 µ D + 3.924 (ε-1)/(2ε+1) 12.22].9 µ D 0.01 E T (30) 0.02 (.99 µ D 0.023 E T (30) 11.213) [.44 µ D 0.018 E T (30) 10.38].03 µ D 0.194 π* 11.09 (.990 µ D 0.19π* 11.29) [.981 µ D 0.18 π* 10.].48 µ D 0.021 log k 2 (LJ) 12.01 (.984 µ D 0.01 log k 2 (LJ) 12.32) [.31 µ D 0.02 log k 2 (LJ) 11.32] 0.108 ε 3.12 (ε-1)/(2ε+1) +13.02 (0.108 ε 3.11 (ε-1)/(2ε+1) + 13.488) [0.10 ε 3.83 (ε-1)/(2ε+1) + 13.18] 0.02 ε + 0.118 E T (30).43 (0.02 ε + 0.118 E T (30).42) [0.024 ε + 0.121 E T (30).283] 11 11 11 118 119 120 121 122 123 124 12 12 12 128 129 130 131 132 3.3 Triple solvent parameter regression analyses Triple solvent parameter regression analyses were performed against log k 2 for aprotic and protic solvents were obtained by using the equation, log k 2 = log k 0 + a 1 X 1 + a 2 X 2 + a 3 X 3 Where, X 1, X 2 and X 3 are independent variables. The results of triple regression analyses are given in Table 9 and 10. The best fit triple regression equations are given in Table 11 for aprotic and protic solvents respectively. 238
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 Table 9 Triple regression of log k 2 vs solvent parameter for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Aprotic solvents) n r s F Regression equation log k 2 = Eqn. no (ε-1)/(2ε+1) + µ D + log k 2 (LJ) 0.2 (0.82) [0.99] 0.211 (0.20) [0.1198] 1.10 (2.) [1.29] 2.84 (ε-1)/(2ε+1) + 0.23 µ D + 0.04 log k 2 (LJ) + 0.01 ( 1.30 (ε-1)/(2ε+1) + 0.3 µ D 0.08 log k 2 (LJ) 0.330) [ 2.182 (ε-1)/(2ε+1) + 0.313 µ D + 0.31 log k 2 (LJ) + 0.22] 1 1 1 (ε-1)/(2ε+1) +µ D + E T (30) 0.83 (0.81) [0.990] 0.1904 (0.218) [0.094] 2. (2.22) [4.41] 4.12 (ε-1)/(2ε+1) + 0.130 µ D + 0.093 E T (30) 2.30 ( 1.030 (ε-1)/(2ε+1) + 0.34 µ D 0.012 E T (30) + 0.13) [.00 (ε-1)/(2ε+1) + 0.41µ D + 0.04 E T (30) 0.09] 18 19 180 (ε-1)/(2ε+1) + µ D + π* 0.23 (0.82) [0.90] 0.21 (0.209) [0.1181] 1.098 (2.4) [1.48] 2.9 (ε-1)/(2ε+1) + 0.280 µ D + 0.03 π* +0.489 ( 1.38 (ε-1)/(2ε+1) + 0.31 µ D 0.3 π* + 0.093) [ 1.83 (ε-1)/(2ε+1) + 0.299 µ D + 1.449 π* 0.834] 181 182 183 log k 2 (LJ) + µ D + E T (30) 0.94 (0.848) [0.934] 0.221 (0.239) [0.133] 1.0 (2.4) [.8] 0.249 log k 2 (LJ) 0.032 µ D + 0.10 E T (30) 4.40 ( 0.03 log k 2 (LJ) + 0.314 µ D 0.012 E T (30) 0.239) [0.43 log k 2 (LJ) + 0.284 µ D 0.041 E T (30) 1.9] 184 18 18 log k 2 (LJ) + µ D + π* 0.93 (0.83) [0.98] 0.22 (0.299) [0.101] 0.924 (2.4) [21.3] 0.342 log k 2 (LJ) + 0.19 µ D + 1.828 π* 1.982 ( 0.43 log k 2 (LJ) + 0.130 µ D + 1.91 π* 2.449) [ 0.934 log k 2 (LJ) + 0.282 µ D +.8 π*.301] 18 188 189 Value in [ ] is for X = C H Table 10 Triple regression of log k 2 vs solvent parameter for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) (Protic solvents) n r s F Regression equation log k 2 = Eqn. no (ε-1)/(2ε+1) + µ D + log k 2 (LJ) 0.99 (0.994) [0.992] 0.100 (0.1144) [0.1293] 34.880 (2.212) [20.309].899 (ε-1)/(2ε+1) + 8.310 µ D + 0.033 log k 2 (LJ) 1.21 (4.89 (ε-1)/(2ε+1) +.02 µ D + 0.090 log k 2 (LJ) 13.9) [.128 (ε-1)/(2ε+1) +.013 µ D + 0.09 log k 2 (LJ) 13.12] 190 191 192 (ε-1)/(2ε+1) +µ D + E T (30) (ε-1)/(2ε+1) + µ D + π* 0.99 (0.980) [0.980] 0.9 (0.98) [0.98] 0.113 (0.14) [0.141] 0.11 (0.140) [0.131] 1.403 (1.391) [1.11] 13.40 (14.0) [14.].241 (ε-1)/(2ε+1) +.890 µ D 0.042 E T (30) 12.918 (4.30 (ε-1)/(2ε+1) +. µ D 0.038 E T (30) 12.832) [4.9 (ε-1)/(2ε+1) +.31µ D 0.03 E T (30) 12.49] 3.24 (ε-1)/(2ε+1) +.822 µ D 0.03 π* 12.31 (2.43 (ε-1)/(2ε+1) +.81 µ D 0.0 π* 12.244) [2.903 (ε-1)/(2ε+1) +.88 µ D 0.00 π* 11.839] 193 194 19 19 19 198 log k 2 (LJ) + µ D + E T (30) 0.99 (0.99) [0.994] 0.088 (0.093) [0.1101] 4.993 (3.082) [28.10] 0.034 log k 2 (LJ) + 4.913 µ D + 0.03 E T (30) 12.11 ( 0.02 log k 2 (LJ) + 4.92 µ D + 0.0 E T (30) 12.32) [ 0.044 log k 2 (LJ) + 4.82 µ D + 0.01 E T (30) 12.14] 199 200 201 log k 2 (LJ) + µ D + π* 0.99 (0.99) [0.994] 0.089 (0.09) [0.1093] 4.901 (3.1) [28.2] 1.10 log k 2 (LJ) +.08 µ D 2.319 π*.29 (1.0 log k 2 (LJ) +.018 µ D 2.123 π* 8.00) [1.138 log k 2 (LJ) +.92 µ D 2.2 π*.28] 202 203 204 Value in [ ] is for X = C H 239
International Journal of Advanced Scientific Research and Management, Volume 3 Issue, July 2018 ISSN 24-38 Table 11 Best- fit triple regression equation for the Reaction between TsCl and X CH(OH)COOH Pyridine (X = H, CH 3, C H ) n r s F Regression equation log k 2 = Eqn. no (Aprotic solvents) (ε-1)/(2ε+1) + µ D + [0.99] [0.1198] [1.29] [ 2.182 (ε-1)/(2ε+1) + 0.313 µ D + 0.31 log k 2 (LJ) + 0.22] 1 log k 2 (LJ) (ε-1)/(2ε+1) +µ D + E T (30) [0.990] [0.094] [4.41] [.00 (ε-1)/(2ε+1) + 0.41µ D + 0.04 E T (30) 0.09] 180 (ε-1)/(2ε+1) + µ D + π* [0.90] [0.1181] [1.48] [ 1.83 (ε-1)/(2ε+1) + 0.299 µ D + 1.449 π* 0.834] 183 log k 2 (LJ) + µ D + π* [0.98] [0.101] [21.3] [ 0.934 log k 2 (LJ) + 0.282 µ D +.8 π*.301] 189 log k 2 (LJ) + µ D + E T (30) [0.934] [0.133] [.8] [0.43 log k 2 (LJ) + 0.284 µ D 0.041 E T (30) 1.9] 18 (ε-1)/(2ε+1) + µ D + log k 2 (LJ) (ε-1)/(2ε+1) +µ D + E T (30) (ε-1)/(2ε+1) + µ D + π* log k 2 (LJ) + µ D + E T (30) log k 2 (LJ) + µ D + π* Value in [ ] is for X = C H 0.99 (0.994) [0.992] 0.99 (0.980) [0.980] 0.9 (0.98) [0.98] 0.99 (0.99) [0.994] 0.99 (0.99) [0.994] 0.100 (0.1144) [0.1293] 0.113 (0.14) [0.141] 0.11 (0.140) [0.131] 0.088 (0.093) [0.1101] 0.089 (0.09) [0.1093] (Protic solvents) 34.880 (2.212) [20.309] 1.403 (1.391) [1.11] 13.40 (14.0) [14.] 4.993 (3.082) [28.10] 4.901 (3.1) [28.2] From the dual regression analyses for aprotic solvents µ D along with (ε-1)/(2ε+1), π* and log k 2 (LJ), ε along with (ε-1)/(2ε+1), E T (30), π* and log k 2 (LJ), ρ along with π*, γ along with E T (30) and η along with E T (30) gives satisfactory correlation. Triple regression analyses show a good correlation for protic solvents and for aprotic solvents good correlation is obtained only for mandelic acid. Sign of the co-efficients in regression equation shows the contribution of the in the studied reaction. 4. Conclusion The kinetic studies on the reaction of p- toluenesulfonyl Chloride (TsCl) with α-hydroxy acid(s) in the presence of pyridine under equimolar conditions in various solvents have been investigated by conductometric method. The rate constants are obtained by the least square method. In order to understand the role of solvents in our studied reactions the log k 2 values against various solvent.899 (ε-1)/(2ε+1) + 8.310 µ D + 0.033 log k 2 (LJ) 1.21 (4.89 (ε-1)/(2ε+1) +.02 µ D + 0.090 log k 2 (LJ) 13.9) [.128 (ε-1)/(2ε+1) +.013 µ D + 0.09 log k 2 (LJ) 13.12].241 (ε-1)/(2ε+1) +.890 µ D 0.042 E T (30) 12.918 (4.30 (ε-1)/(2ε+1) +. µ D 0.038 E T (30) 12.832) [4.9 (ε-1)/(2ε+1) +.31µ D 0.03 E T (30) 12.49] 3.24 (ε-1)/(2ε+1) +.822 µ D 0.03 π* 12.31 (2.43 (ε-1)/(2ε+1) +.81 µ D 0.0 π* 12.244) [2.903 (ε-1)/(2ε+1) +.88 µ D 0.00 π* 11.839] 0.034 log k 2 (LJ) + 4.913 µ D + 0.03 E T (30) 12.11 ( 0.02 log k 2 (LJ) + 4.92 µ D + 0.0 E T (30) 12.32) [ 0.044 log k 2 (LJ) + 4.82 µ D + 0.01 E T (30) 12.14] 1.10 log k 2 (LJ) +.08 µ D 2.319 π*.29 (1.0 log k 2 (LJ) +.018 µ D 2.123 π* 8.00) [1.138 log k 2 (LJ) +.92 µ D 2.2 π*.28] at microscopic and macroscopic levels are subjected to simple and multiple regression analyses. Simple regression analyses gives only poor correlation and multiple regression analysis shows good correlation. From the results we conclude that more than one solvent parameter may influence the rate of the reaction. References [1] Ananthalakshmi S, Nallu M, Kinetic investigation on the Reactions of p toluenesulfonyl chloride with p substituted benzoic acid(s) in the presence of triethylamine in aprotic solvents, Int. J. Chem. Kinet, DOI 10. 1002/ Kin. (2008). [2] Drougard Y and Decroocq D, L ifluence du solvent sur la reaction chimique. II. - Etude et correlation des effets physiques du milieu, Bull. Soc. Chim. France, 292, (199). [3] Grahain Dawber J, Ward Williams J, A study in preferential solvation using a solvatochromic pyridinium betaine and its 190 191 192 193 194 19 19 19 198 199 200 201 202 203 204 240
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