Original Article
Phys Chem Ind J, Volume: 12( 3)

Studies in Thermo-Physical Parameters of N-Benzothiazol-2-Yl-3, 5-Disubstituted Pyrazolines in Binary Liquid Mixtures at Different Temperatures

*Correspondence:
Gotmare AG Department of Chemistry, Shri Shivaji Science College, Amravati-444603 Maharashtra, India
Tel: 07212660855; E-mail: [email protected]

Received Date: July 18, 2017 Accepted Date: August 31, 2017 Published Date: September 04, 2017

Citation: Gotmare AG, Burghate AS, Wadhal SA. Studies in Thermo-Physical Parameters of N-Benzothiazol-2-Yl-3, 5-Disubstituted Pyrazolines in Binary Liquid Mixtures at Different Temperatures. Phys Chem Ind J. 2017;12(3):114

Abstract

Viscosity (η) measurements were carried out for N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines viz. (BHPMPP), (BHPPP), (BHPCPP), (BHMPMPP), (BHMPPP), (BHMPCPP) in binary solvents at 295.15 K, 300.15 K and 305.15 K. With the help of above data molar volume (V_m), Enthalpy (ΔH), Entropy (ΔS) and Gibb’s energy (ΔG) of activation were calculated. The above study has been extended in determination of excess parameters. Results used to establish the intermolecular interaction between molecules.

Keywords

Viscosity; N-Benzothiazol-2-yl-3;5-disubstituted pyrazoline; Enthalpy; Entropy; Gibb’s energy

Introduction

Information on intermolecular force is obtained by macroscopic measurements of properties like viscosity which point the existence and action of forces at a molecular level [1-7]. Viscosity is one of the unique physical property [8-10], generally taken into consideration for study of liquids or liquid mixtures [11,12]. The viscosity of a system is determined by how molecules constituting the system interact.

Interaction between molecules played a major part in determining the properties of matter. Molecular interactions are of key importance in diverse fields of protein folding, drug design, separation technologies etc.

The system that has been taken for the further investigation is a binary system in which molecular recognition is studied between the N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines with three different solvents i.e. DMSO, dioxan and acetone. The solvent have versatile and wide applications. It is therefore, not surprising that it has been the subject of extensive investigation resulting in the accumulation of an immense literature.

As we know heterocyclic compounds have special appearance in terms of properties. Every heterocyclic compounds are best known for their applications in pharmacy, industry, medicine, agriculture etc. as they have tremendous variety of applications [13]. Pyrazolines are one of them and known from long time. The molecular interactions of pyrazolines are best known for antimicrobial [14], analgesics [15], antidepressant [16], antitumor [17,18], anti-HIV [19], antifungal, antibacterial [20,21], anti-cancer [22] etc. Some other activities are also shown by pyrazolines [23,24].

For this, measurement of density, viscosity, molar volume of the binary mixtures are performed over the entire range of composition in the temperature range of (295.15 K to 305.15 K) at intervals of 5 K. In present investigation, we report viscosities (η) and molar volume (vm) of the binary mixtures of N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines can be discussed in terms of solute-solute, solute-solvent, solvent-solvent types of interactions.

Experimental Section

Materials

The compounds N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines was a discovered compound and further used to investigate physical properties [25]. The distilled deionised water with a conductivity approximately 1 × 10-4 S∙m-1 was used in experimentation. Solutions were prepared on the basis of stoichiometry. The balance Contech balance ( ± 0.001 g) used for weighing purpose.

Apparatus and procedure

The densities of solutions were measured by densitometer DMA 35 (Anton Paar) by calibrate and taking proper care of it. The accuracy of densitometer was ± 5 × 10-4 g∙cm3. For the determination of viscosity Ostwald’s viscometer was used and calibrated it by using double distilled deionized water and benzene. The viscosity measurement was done for pure solvents and their mixture at atmospheric pressure and T/K=(295.15 to 305.15). For the determination of viscosity temperature was maintained at temperature control thermostat by Bio technics India (Model BTI-05) which required approximately 30 mins. for thermal stability and which has accuracy of about ± 0.01 K. Flow time was measured by using electronic digital stopwatch which shows uncertainty of about ± 0.01 S.

The viscosity (η) was calculated by using following relationship

equation

Where, η and equation are the viscosity, density and flow time of mixtures and pure water respectively.

Results and Discussion

The viscosities of pure solvents i.e. DMSO, dioxan and acetone are shown in Table 1 and calculated viscosities of N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines in binary mixture i.e. DMSO-water, dioxan-water and acetone-water at temperature T/K=(295.15 to 305.15) are listed in Table 2. With this calculated molar volume (vm ) are also shown in Table 2, by using following formula:

Sr. No. Solvents 103∙η/kg∙m-1∙s-1
-- -- 295.15 K 300.15 K 305.15 K
1 DMSO 1.86 1.63 1.54
2 Dioxan 1.15 1.06 0.993
3 Acetone 0.451 0.393 0.344

Table 1. Experimental viscosities (η) of solvents (DMSO, dioxan, acetone) at T/K=(295.15 to 303.15).

X1 X2 103∙η/kg∙m-1∙s-1  Vm/m3∙mol-1 103η/kg∙m-1∙s-1 Vm/m3∙mol-1 103η/kg∙m-1∙s-1  Vm/m3∙mol-1
-- -- 295 K -- 300 K -- 305 K --
DMSO+Water
BHPMPP
0.479578587 0.5204094 2.91 0.0425272 2.76 0.042728 2.65 0.0427028
0.479572777 0.5204031 2.92 0.0427853 2.79 0.043145 2.71 0.0427276
0.479567004 0.5203968 3.01 0.0427561 2.91 0.0427362 2.8 0.0426158
0.479561195 0.5203905 3.05 0.0430566 2.96 0.0427262 2.89 0.0425131
0.479555386 0.5303842 3.12 0.0428672 3.04 0.0428069 2.98 0.0424922
BHMPMPP
0.47958161 0.5204089 2.71 0.0428942 2.56 0.0427767 2.47 0.0424948
0.479571962 0.5204022 2.77 0.0428818 2.62 0.0427406 2.54 0.04274
0.479565764 0.5203955 2.84 0.0427348 2.7 0.0428073 2.62 0.0428087
0.479559565 0.5203887 2.93 0.0426872 2.79 0.042795 2.74 0.0427167
0.479553329 0.520382 3.02 0.0430489 2.87 0.0428868 2.83 0.0425696
  Dioxane+Water      
        BHPMPP      
0.449685113 0.5503022 1.41 0.0488167 1.33 0.048519 1.23 0.0487991
0.44679353 0.5502951 1.49 0.0479245 1.38 0.0485996 1.32 0.048415
0.449673629 0.5502881 1.56 0.0481522 1.45 0.0486855 1.38 0.0487732
0.449667869 0.5502811 1.63 0.0485117 1.54 0.048636 1.47 0.0484761
0.449662109 0.550274 1.72 0.0484288 1.63 0.0482754 1.56 0.0482352
-- -- -- -- BHMPMPP -- -- --
0.449684691 0.5503016 1.5 0.0485856 1.36 0.0482534 1.27 0.0482515
0.449678545 0.5502941 1.55 0.0485032 1.44 0.0482832 1.32 0.0483356
0.449672398 0.5502866 1.62 0.0488447 1.51 0.0494189 1.43 0.048943
0.449666252 0.5502791 1.68 0.0487651 1.62 0.0483965 1.54 0.0487106
0.44966007 0.5502715 1.74 0.0487127 1.67 0.0485104 1.61 0.0484347
        Acetone+Water      
        BHPMPP      
0.553499818 0.4464899 6.74 0.0476726 6.35 0.046023 5.76 0.0466358
0.553494066 0.4464852 7.22 0.0474799 6.61 0.0473873 6.18 0.046852
0.55348849 0.4464806 7.58 0.0480707 7.05 0.0473821 6.54 0.0474031
0.553482597 0.446476 8.13 0.0474927 7.48 0.0475042 7.04 0.0470054
0.553476845 0.4464713 8.4 0.0485239 7.95 0.0472825 7.69 0.0470576
-- -- -- -- BHMPMPP -- -- --
0.553499397 0.4464895 7.22 0.0475219 6.59 0.0475504 5.85 0.0477466
0.553493259 0.4464846 7.69 0.0473869 7.06 0.0473512 6.41 0.048413
0.553487121 0.4464796 8.13 0.047449 7.44 0.0477109 6.98 0.047438
0.553480983 0.4464747 8.79 0.0475584 8.15 0.0474037 7.7 0.0470092
0.553474808 0.4464697 9.32 0.0471442 8.96 0.0466266 8.39 0.0468179

Table 2. Experimental viscosities (η)a and molar volume (Vm) of solvent (DMSO, dioxan, acetone)+water binary mixture from T/K=(295.15 to 303.15).

equation

Where x1, x2 are mole fraction of solvent (DMSO, dioxan and acetone) and distilled water.

From the data listed in Table 2, with increase in temperature for the selected systems in binary solvent mixtures, there is decrease in the viscosity as well as molar volume. The reverse trend is observed, as there is increase in concentration, the viscosity and molar volume values are also increases.

The above results are obtained since the existence of liquids depends on intermolecular forces, we might expect that studies of the liquid state would provide much information about molecular interactions. In liquid, each molecule surrounded by a substantial number of relatively near neighbors and feels their attractive intermolecular interactions while in isolated molecules intermolecular energy is very small in comparison with the kinetic energy of the molecules. Hence in above case, increase in temperature, increases the kinetic or thermal energy which in turn increases the mobility of ions.

Values of molar volume are observed to decrease with increasing temperature. This is because the interaction of molecules of N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines between molecules of solvent decreases with increasing temperature. The molecular thermal motion intensified with increasing temperature and the interaction between molecules correspondingly weakened so the difference of solution structure and solvent structure decreases gradually.

Thermodynamic properties give more emphasis on interactions between the hetero molecules and solute-solvent interactions. Hence parameters like Gibb’s energy of activation of viscous flow (ΔG), enthalpy (ΔH) and entropy (ΔS) are also calculated and listed in Table 3, and shown in Figure. 1, these values are determined by using following relationship.

physical-chemistry-enthalpies

Figure 1: Comparison of enthalpies (ΔH), Gibb’s energy of activation (ΔG) and entropies (ΔS) of solvent (DMSO, Dioxan, Acetone)+water binary mixture with mole fraction.

X1 X2 ∆H/kJ∙Mol-1 ∆G/kJ∙Mol-1 ∆S/J∙K-1∙Mol-1
     DMSO+Water    
    BHPMPP    
0.4795786 0.5204094 840.655 -46.942827 -2.95866
0.4795728 0.5204031 669.368 -35.683901 -2.35017
0.479567 0.5203968 651.715 -35.55944 -2.29092
0.4795612 0.5203905 484.15 -27.572879 -1.70574
0.4795554 0.5303842 412.355 -25.529806 -1.45962
     BHPPP    
0.4795776 0.5204083 784.961 -41.167841 -2.75376
0.4795709 0.520401 691.005 -30.316764 -2.40441
0.4795642 0.5203937 611.898 -31.331599 -2.1441
0.4795574 0.5203864 532.338 -22.773995 -1.85105
0.4795507 0.5203791 544.449 -43.400478 -1.9595
    BHPCPP    
0.4795787 0.5204095 777.372 -40.118539 -2.72497
0.4795731 0.5204034 684.534 -29.679141 -2.38071
0.4795674 0.5203973 671.651 -38.295666 -2.36649
0.4795618 0.5203911 661.28 -34.305257 -2.31862
0.4795562 0.520385 622.633 -39.253057 -2.20629
     BHMPMPP    
0.4795816 0.5204089 831.551 -42.85285 -2.91468
0.479572 0.5204022 776.59 -38.295666 -2.71628
0.4795658 0.5203955 722.727 -36.166427 -2.52964
0.4795596 0.5203887 598.877 -33.508708 -2.10795
0.4795533 0.520382 579.389 -32.976398 -2.04122
    BHMPPP    
0.4795771 0.5204078 890.485 -45.954799 -3.12147
0.4795699 0.5203999 789.176 -38.295666 -2.75824
0.4795626 0.520392 700.689 -32.24878 -2.44313
0.4795554 0.5203842 648.241 -33.508708 -2.2725
0.4795481 0.5203763 632.245 -34.812675 -2.22352
    BHMPCPP    
0.4795784 0.5204091 975.432 -46.500512 -3.40644
0.4795723 0.5204026 949.75 -47.364079 -3.32371
0.4795663 0.520396 917.241 -49.380346 -3.22207
0.4795602 0.5203895 824.768 -45.954799 -2.90241
0.4795542 0.5203829 728.711 -39.89068 -2.56201
     Dioxan+Water    
     BHPMPP    
0.4496851 0.5503022 1232.36 -29.104706 -4.2049
0.4496794 0.5502951 1085.66 -28.036257 -3.71232
0.4496736 0.5502881 1100.07 -34.305257 -3.78126
0.4496679 0.5502811 928.484 -28.338793 -3.18941
0.4496621 0.550274 877.427 -26.806966 -3.01411
     BHPPP    
0.4496842 0.550301 955.45 -27.764358 -3.27738
0.4496775 0.5502928 985.05 -29.225337 -3.38092
0.4496708 0.5502847 1056.08 -33.072137 -3.6305
0.4496642 0.5502765 1103.31 -37.424439 -3.80244
0.4496575 0.5502683 1137.37 -43.082624 -3.93486
     BHPCPP    
0.4496853 0.5503023 1515.38 -44.677639 -5.2002
0.4496796 0.5502955 1446.3 -41.941413 -4.96081
0.4496741 0.5502886 1156.26 -35.232013 -3.97163
0.4496685 0.5502818 1099.68 -34.466099 -3.78049
0.4496629 0.5502749 960.65 -32.823215 -3.31158
    BHMPMPP    
0.4496847 0.5503016 1493.88 -39.768134 -5.11215
0.4496785 0.5502941 1447.88 -42.125232 -4.96668
0.4496724 0.5502866 1120.59 -34.263132 -3.84949
0.4496663 0.5502791 785.385 -23.402481 -2.69596
0.4496601 0.5502715 698.313 -22.337862 -2.40217
     BHMPPP    
0.4496837 0.5503004 717.955 -21.062616 -2.46339
0.4496765 0.5502916 914.615 -28.721749 -3.14446
0.4496693 0.5502828 939.939 -28.721749 -3.22887
0.4496621 0.550274 1005.5 -34.812675 -3.4677
0.4496549 0.5502652 1177.86 -40.036204 -4.05965
     BHMPCPP    
0.4496849 0.5503019 868.072 -24.892183 -2.97655
0.4496789 0.5502945 1221.21 -35.423491 -4.18878
0.4496729 0.5502872 1421.74 -46.127129 -4.8929
0.4496669 0.5502799 1520.67 -49.784366 -5.23485
0.4496609 0.5502726 1598.97 -54.571324 -5.51181
    Acetone+Water    
    BHPMPP    
0.5534998 0.4464899 1420.04 -172.3305 -5.30792
0.5534941 0.4464852 1396.93 -183.8192 -5.26917
0.5534885 0.4464806 1328.81 -169.59427 -4.9947
0.5534826 0.446476 1292.4 -181.39891 -4.91267
0.5534768 0.4464713 791.67 -118.71656 -3.03462
     BHPPP    
0.5534989 0.4464891 1822.14 -199.98763 -6.74044
0.5534922 0.4464837 1407.21 -169.59427 -5.25601
0.5534855 0.4464783 1278.29 -167.10697 -4.81798
0.5534789 0.446473 1168.21 -159.07254 -4.42427
0.5534722 0.4464676 989.904 -153.18266 -3.81029
    BHPCPP    
0.5535 0.44649 2187.83 -260.41053 -8.16081
0.5534944 0.4464854 2187.38 -255.24061 -8.14207
0.5534888 0.4464809 1913.15 -268.06966 -7.27072
0.5534832 0.4464764 1715.11 -265.51534 -6.60207
0.5534776 0.4464719 1579.74 -255.3038 -6.11682
    BHMPMPP    
0.5534994 0.4464895 1898.23 -229.77399 -7.09336
0.5534933 0.4464846 1640.52 -212.73242 -6.17749
0.5534871 0.4464796 1369.12 -199.13746 -5.22754
0.553481 0.4464747 1188.94 -191.47833 -4.60141
0.5534748 0.4464697 950.221 -153.18266 -3.67801
    BHMPPP    
0.5534984 0.4464887 1585.95 -183.8192 -5.89923
0.5534912 0.4464829 1503.91 -191.47833 -5.65129
0.553484 0.4464771 1286.95 -194.42327 -4.93792
0.5534768 0.4464713 1075.55 -172.3305 -4.15959
0.5534696 0.4464655 1069.62 -183.8192 -4.17811
    BHMPCPP    
0.5534996 0.4464897 2567.22 -295.42234 -9.54214
0.5534936 0.4464848 2147.24 -160.8418 -7.69362
0.5534876 0.44648 1765.7 -222.71034 -6.62605
0.5534816 0.4464752 1448.24 -226.71034 -5.58318
0.5534757 0.4464704 1372.28 -222.11486 -5.31466

Table 3. Experimental enthalpies (ΔH), Gibb’s energy of activation (ΔG) and entropies (ΔS) of solvent (DMSO, Dioxan, Acetone)+water binary mixture.

equation (A.3)

equation (A.4)

equation (A.5)

Where, R is gas constant and T is absolute temperature. equation are difference of the viscosities of two temperatures, T1 and T2 are temperatures at two different range. ΔH is change in enthalpy and ΔG change in Gibb’s energy of activation.

From the observed data, Gibb’s energy values at various concentrations are negative consequently change in enthalpy is positive and entropy change is negative. The results are discussed on the basis of solution formation. When the enthalpy of pure components are determined, the values indicates equation Intermolecular forces between unlike molecules leading to a non-ideal solution and depends on adhesive and cohesive forces. If adhesive forces are less than cohesive forces,equation At the limit these solutions are heterogeneous. Whenever there is a tendency for the solvent to solvate with the solute i.e. whenever there are strong specific forces between the dissimilar molecules, the observed solubility may well be larger than the ideal solubility. Enhanced solubility is observed whenever there are negative deviations from Raoult’s law in the liquid solution, such deviations frequently occur in polar systems, especially in systems where hydrogen bonding between solute and solvent is strong. However, even in nonpolar systems, specific solvation forces may be sufficiently strong to result in solubility’s above the ideal. Mixing liquids of different degrees of order usually brings about a net decrease of order and hence positive contributions to the enthalpy equation of mixing.

From the investigations of the solvation of ions and dipolar molecules in binary solvent mixtures it has been found that the ratio of solvent components in the solvent shell can be different from that in the bulk solution. As expected, the solute is surrounded preferably by the component of the mixture which leads to the more negative Gibb’s energy of solvation equation while Gibb’s energy values found to be reversed because of dissolution of selected systems in binary solvent mixtures are exothermic.

Measured values of density and viscosity are used to calculate excess parameters like excess molar volume equation excess viscosityequation excess Gibb’s energy of activation of viscous flow equation are listed in Table 4 and shown in Figure. 2-4, for the same following relationships are used

equation (A.6)

equation (A.7)

equation (A.8)

Where, for each equation, ρ, η and Vm are density, viscosity and molar volume of the mixtures and xi,Vmi, Mi and equation are the mole fraction, molar volume, molar mass and viscosity of the compounds DMSO, dioxan and acetone (1) and water (2) respectively, R is gas constant and T is absolute temperature.

The excess parameters of the selected systems in binary solvent mixtures are presented in Table 4 and shown inFigure. 2-4.

physical-chemistry-excess-viscosity

Figure 2: Variation of excess viscosity (ηE) with mole fraction of solvent (DMSO, dioxan, acetone)+water binary mixture.

physical-chemistry-molar-volume

Figure 3: Variation of excess molar volume (VmE) with mole fraction of solvent (DMSO, dioxan, acetone)+water binary mixture.

X1 X1    103ηE     10-3∙VmE      G*E  
    295.15 K 300.15 K 305.15 K 295.15 K 300.15 K 305.15 K 295.15 K 300.15 K 305.15 K
            DMSO+Water        
             BHPMPP        
0.4795786 0.5204094 1.23 1.29 1.29 -1.0049 -1.24 -1.8 -8604.8723 -8731.0127 -8878.8118
0.4795728 0.5204031 1.24 1.32 1.32 -0.64637 -0.6489 -1.7677 -8590.0581 -8706.7928 -8877.5439
0.479567 0.5203968 1.33 1.44 1.44 -0.69336 -1.2314 -1.9312 -8591.7361 -8730.5386 -8884.2142
0.4795612 0.5203905 1.37 1.49 1.49 -0.27507 -1.2511 -2.0819 -8574.5549 -8731.1178 -8890.3334
0.4795554 0.5303842 1.44 1.57 1.57 -0.54803 -1.1431 -2.1171 -8585.3674 -8726.4119 -8891.5803
             BHPPP        
0.4795776 0.5204083 0.94 0.995 1.01 -1.1808 -1.0356 -1.8632 -8612.0876 -8722.9102 -8881.8105
0.4795709 0.520401 1.01 1.08 1.1 -0.68586 -1.4981 -1.9973 -8591.6276 -8741.7988 -8887.2092
0.4795642 0.5203937 1.04 1.12 1.15 -0.76625 -1.0866 -1.9072 -8594.6536 -8724.5089 -8883.1533
0.4795574 0.5203864 1.09 1.19 1.22 -0.48372 -0.86129 -1.5648 -8582.9316 -8714.9725 -8868.5015
0.4795507 0.5203791 1.22 1.35 1.34 -0.20485 -1.2048 -1.7034 -8571.41 -8728.8835 -8874.0592
             BHPCPP        
0.4795787 0.5204095 0.98 1.08 1.05 -0.08793 -1.5935 -2.2214 -8567.7116 -8746.0397 -8896.9634
0.4795731 0.5204034 1.03 1.09 1.12 -0.5045 -1.1499 -1.8046 -8584.3065 -8727.4084 -8879.1222
0.4795674 0.5203973 1.08 1.14 1.16 -0.32194 -0.39784 -0.80729 -8576.6888 -8696.2998 -8837.2565
0.4795618 0.5203911 1.14 1.24 1.23 -0.38452 -1.2837 -1.7786 -8578.9882 -8732.4741 -8877.5563
0.4795562 0.520385 1.19 1.36 1.29 -0.79064 -1.3519 -1.877 -8595.2415 -8735.0667 -8881.4588
             BHMPMPP        
0.4795816 0.5204089 1.03 1.09 1.08 -0.48713 -1.1629 -2.0907 -8583.8236 -8728.1711 -8891.4236
0.479572 0.5204022 1.09 1.15 1.15 -0.51062 -1.2198 -1.7506 -8584.5356 -8730.2818 -8876.8329
0.4795658 0.5203955 1.16 1.23 1.23 -0.72392 -1.1315 -1.6595 -8592.9573 -8726.3878 -8872.7593
0.4795596 0.5203887 1.25 1.32 1.35 -0.797 -1.1548 -1.7953 -8595.6925 -8727.1049 -8878.2172
0.4795533 0.520382 1.34 1.4 1.44 -0.29266 -1.0312 -2.0087 -8574.9964 -8721.7593 -8886.9635
             BHMPPP        
0.4795771 0.5204078 0.96 0.995 1 -0.28699 -0.94014 -1.6466 -8575.7034 -8718.9668 -8872.6961
0.4795699 0.5203999 1.04 1.08 1.1 -0.16937 -0.98418 -1.9043 -8570.7087 -8720.5191 -8883.2686
0.4795626 0.520392 1.11 1.18 1.19 -0.31882 -1.1977 -2.1054 -8576.4831 -8729.0702 -8891.4942
0.4795554 0.5203842 1.19 1.28 1.28 -0.15677 -1.0133 -1.6382 -8569.688 -8721.198 -8871.546
0.4795547 0.5203764 1.26 1.35 1.35 0.080272 -0.52262 -1.2652 -8559.897 -8700.7937 -8855.6746
             BHMPCPP        
0.4795184 0.5204091 0.93 0.935 0.954 -0.2163 -0.97787 -2.5331 -8572.8782 -8720.5408 -8910.2016
0.4795723 0.5204026 1 1.02 1.02 -0.61113 -0.72961 -1.3336 -8588.6195 -8710.094 -8859.3646
0.4795663 0.520396 1..09 1.11 1.11 -0.49098 -0.82948 -0.7838 -8583.5088 -8713.9532 -8836.2685
0.4795602 0.5203895 1.16 1.2 1.22 -0.25585 -0.99931 -2.2261 -8573.7626 -8720.7003 -8896.4222
0.4795542 0.5203829 1.26 1.31 1.32 -0.46209 -1.5121 -1.8499 -8581.8643 -8741.6813 -8880.2809
            Dioxan+Water        
             BHPMPP        
0.4496851 0.5503022 2.98 3.11 2.82 -0.8 -0.08 -1.86 -8389.1557 -8543.6915 -8667.5746
0.4496794 0.5502951 3.78 3.61 3.72 -2.1339 0.035844 -2.4403 -8434.603 -8539.5488 -8687.7243
0.4496736 0.5502881 4.48 4.31 4.32 -1.8 0.15747 -1.9113 -8422.9729 -8562.61 -8668.8425
0.4496679 0.5502811 5.18 5.21 5.22 -1.2694 0.076555 -2.3626 -8404.733 -8537.6823 -8684.5269
0.4496621 0.550274 6.08 6.11 6.12 -1.4002 -0.46957 -2.7296 -8408.9282 -8556.2478 -8697.161
             BHPPP        
0.4496842 0.550301 4.68 4.51 4.72 -1.4862 -0.40559 -2.446 -8412.7546 -8554.9629 -8688.1477
0.4496775 0.5502928 5.18 4.91 5 -0.99484 0.26008 -1.7419 -8395.8985 -8531.8343 -8663.3501
0.4496708 0.5502847 5.98 5.71 5.72 -0.89091 -0.021534 -2.3184 -8392.154 -8541.2368 -8683.173
0.4496642 0.5502765 7.08 6.91 6.62 -1.0385 -0.55218 -2.5093 -8396.8781 -8559.2773 -8689.601
0.4496575 0.5502683 8.28 8.11 7.62 -1.6788 -0.14991 -2.2468 -8418.3078 -8545.1487 -8680.1602
             BHPCPP        
0.4496853 0.5503023 4.38 4.11 3.62 -1.171 0.21213 -1.8314 -8402.1046 -8533.7449 -8666.733
0.4496796 0.5502955 5.08 4.91 4.32 -1.7332 0.2506 -1.7675 -8420.9337 -8532.195 -8664.2758
0.4496741 0.5502886 5.48 5.41 5.12 -1.2936 0.17503 -1.7294 -8405.7927 -8534.5502 -8662.7201
0.4496685 0.5502818 6.28 6.21 5.92 -1.1209 0.16014 -1.986 -8399.7289 -8534.827 -8671.3973
0.4496629 0.5502749 7.58 7.31 7.32 -1.0359 -0.20892 -2.2605 -8396.6355 -8547.2709 -8680.7338
             BHMPMPP        
0.4496847 0.5503016 3.88 3.41 3.22 -1.1384 -0.47537 -2.6782 -8400.996 -8557.3819 -8696.3031
0.4496724 0.5502866 5.08 4.91 4.82 -0.76518 1.2536 -1.6581 -8387.9541 -8497.8499 -8660.2189
0.4496663 0.5502791 5.68 6.01 5.92 -0.89118 -0.28235 -2.0127 -8391.951 -8549.99 -8672.2874
0.4496601 0.5502715 6.28 6.51 6.62 -0.97664 -0.11917 -2.4323 -8394.5878 -8544.1334 -8686.6902
             BHMPPP        
0.4496837 0.5503004 4.58 5.01 5.02 -0.82524 -0.29602 -2.4874 -8390.4316 -8551.1753 -8689.5919
0.4496765 0.5502916 5.48 5.71 5.52 -1.1672 -0.16149 -2.3888 -8401.6963 -8546.2827 -8685.8741
0.4496693 0.5502828 6.08 6.31 6.02 -1.2458 -0.36105 -2.4138 -8404.097 -8552.8998 -8686.6424
0.4496621 0.550274 6.88 6.91 6.62 -1.4802 -0.46398 -2.4489 -8411.7792 -8556.1959 -8687.4523
0.4496549 0.5502652 7.68 7.61 7.02 -1.2014 -0.084487 -2.1794 -8402.0897 -8542.8581 -8677.7664
             BHMPCPP        
0.4496849 0.5503019 4.08 4.21 4.32 -1.1416 -0.24907 -3.1803 -8401.1082 -8549.5773 -8714.0108
0.4496789 0.5502945 5.38 5.01 4.92 -0.6508 -0.50401 -2.298 -8384.3605 -8558.1364 -8682.7384
0.4496729 0.5502872 6.58 5.71 5.62 -1.416 0.090442 -1.5008 -8409.916 -8537.4291 -8654.7828
0.4496669 0.5502799 7.48 6.61 6.22 -0.63794 -0.44963 -1.8234 -8383.4588 -8555.7781 -8665.7162
0.4496609 0.5502726 8.48 7.41 6.92 -1.2024 -0.42783 -1.7681 -8402.2197 -8554.7859 -8663.5545
            Acetone+Water        
             BHPMPP        
0.5534998 0.4464899 1.22 1.5 1.47 -4.72 -7.73 -8.06 -8201.6453 -8423.2173 -8526.3271
0.5534941 0.4464852 1.7 1.76 1.89 -4.9584 -6.0337 -7.7905 -8211.8224 -8350.387 -8514.8187
0.5534885 0.4464806 2.06 2.2 2.25 -4.2282 -6.0459 -7.1097 -8181.4884 -8350.6623 -8485.1625
0.5534826 0.446476 2.61 2.63 2.75 -4.9538 -5.8996 -7.6107 -8450.0531 -8344.2433 -8506.5272
0.5534768 0.4464713 2.88 3.1 3.4 -3.6756 -6.1813 -7.5514 -8397.3719 -8355.9077 -8503.7154
             BHPPP        
0.5534989 0.4464891 1.48 1.57 1.43 -4.9716 -6.279 -7.6112 -8451.4831 -8360.9967 -8507.2686
0.5534922 0.4464837 1.93 1.98 2.08 -4.9624 -6.0455 -7.5223 -8450.8484 -8350.849 -8503.1559
0.5534855 0.4464783 2.21 2.46 2.42 -3.619 -6.3154 -6.6743 -8395.5043 -8362.0288 -8466.478
0.5534789 0.446473 2.68 3.1 2.92 -3.8744 -6.1534 -7.2153 -8405.63 -8354.9004 -8489.3909
0.5534722 0.4464676 3.3 3.45 3.61 -5.0821 -5.5124 -7.4822 -8455.0598 -8327.647 -8500.6377
             BHPCPP        
0.5535 0.44649 1.52 1.35 1.23 -5.3331 -6.3427 -7.8604 -8466.5478 -8363.7196 -8518.1043
0.5534944 0.4464854 2.05 1.96 1.65 -5.8761 -5.8708 -7.6397 -8489.0793 -8343.522 -8508.2775
0.5534888 0.4464809 2.62 2.42 2.29 -5.0868 -6.0426 -7.4535 -8455.8182 -8350.5311 -8499.9786
0.5534832 0.4464764 3.27 2.65 2.97 -4.8672 -6.0667 -7.6114 -8446.4721 -8351.3072 -8506.5665
0.5534776 0.4464719 3.73 3.26 3.47 -4.9483 -7.3485 -6.4318 -8449.6029 -8405.8639 -8455.7368
             BHMPMPP        
0.5534994 0.4464895 1.7 1.74 1.56 -4.9006 -5.825 -6.6706 -8448.5488 -8341.8175 -8466.8524
0.5534933 0.4464846 2.17 2.21 2.12 -5.0745 -6.0791 -5.8465 -8455.5224 -8352.2891 -8431.7066
0.5534871 0.4464796 2.61 2.59 2.69 -5.0031 -5.6369 -7.0668 -8452.3121 -8333.4089 -8483.2997
0.553481 0.4464747 3.27 3.3 3.41 -4.8728 -6.0254 -7.6067 -8446.6662 -8349.5247 -8506.3235
0.5534748 0.4464697 3.8 4.11 4.1 -5.3945 -6.999 -7.8508 -8468.1196 -8390.7506 -8516.666
             BHMPPP        
0.5534984 0.4464887 1.34 1.37 1.46 -5.7383 -6.4771 -7.8762 -8483.4886 -8369.4087 -8464.4806
0.5534912 0.4464829 1.83 1.94 1.93 -5.9555 -5.6778 -6.1349 -8492.3724 -8335.3421 -8443.8281
0.553484 0.4464771 2.17 2.13 2.37 -5.047 -5.4598 -6.249 -8454.082 -8325.9326 -8448.3847
0.5534768 0.4464713 2.62 2.4 2.92 -5.055 -4.0442 -3.6168 -8454.1518 -8267.1161 -8339.0607
0.5534696 0.4464655 2.97 2.87 3.24 -4.3757 -4.3657 -4.5758 -8425.8329 -8280.0288 -8377.9789
             BHMPCPP        
0.5534996 0.4464897 1.62 1.4 1.08 -4.2912 -4.6801 -3.7898 -8423.4369 -8294.071 -8346.9209
0.5534936 0.4464848 2.24 1.93 1.82 -3.8744 -3.6356 -2.959 -8406.1606 -8251.0465 -8313.1098
0.5534876 0.44648 2.82 2.56 2.56 -4.8371 -5.3878 -5.9926 -8445.4427 -8322.987 -8437.6179
0.5534816 0.4464752 3.17 2.89 3.1 -4.1561 -4.5537 -5.1615 -8417.1768 -8288.1152 -8402.574
0.5534757 0.4464704 3.81 3.77 3.72 -4.0206 -4.7232 -5.0451 -8411.3966 -8294.8665 -8397.4874

Table 4. Experimental excess viscosities (ηE), excess molar volume (VmE) and excess Gibb’s energy of activation (G*E) of solvent (DMSO, dioxan, acetone)+water binary mixture from T/K=(295.15 to 303.15).

physical-chemistry-binary-mixture

Figure 4: Variation of excess Gibb’s energy of activation (G*E) with mole fraction of solvent (DMSO, dioxan, acetone)+water binary mixture.

The excess parameters equation values increases with increase in temperature as well as in concentration.

The negative equation values indicate the presence of strong molecular interactions between the components of the mixtures. The forces are responsible for the interactions are non-specific and specific forces which can be saturated and lead to stoichiometric molecular compounds. The structure and size of N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines lead to interstitial accommodation with binary solvent mixtures.

From the tabulated data, excess molar volume equation of binary systems are negative over the entire composition range (295.15 to 305.15) K and at atmospheric pressure while exceptions observed because of the overlapping of solute-solvent interactions and hydrogen bonding between the molecules. The influence of temperature on equation for the systems is slightly more negative with increasing temperature. This can be happened because of the relative orientations of molecules depend on the interplay of two factors : i) The presence of an electric field set up by the polar molecules tend to live up the dipoles whereas the kinetic energy of the molecules tends to toss them about in a random manner.

A correlation between the signs of equation and equation has been observed for a number of binary solvent systems [26,27] i.e. equation is positive when equation is negative and vice versa. equation is negative because of dispersion forces and dipolar interactions. The excess viscosity values are explained in Table 4 and shown in Figure. 2.

The values of excess viscosity found to be positive because of hydrogen bonding which is responsible for the strong, temperature-dependent self and hetero-association of amphiprotic solvents. Cooperative solvent/solvent interactions such as chain wise association by intermolecular hydrogen bonding [28].

From the Table 4 and Figure. 4, it is clear that, the values of equation are found to be negative. By increasing temperature the values also increase. The results are obtained so because of the change in intermolecular free space. The changes occur because of ions as structure makers and structure breakers. If ions with high charge density are strongly coordinated, leading to well defined ion/water complexes i.e. structure makers and larger weakly interacting monovalent ions have only a small influence on the orientation of the surrounding water molecules and mainly disrupt the H-bond network of bulk water with structure breaking as net effect. According to Reed and Taylor [29] and Palepu et al. [30], equation may be considered as a reliable criterion to detect or exclude the presence of interaction between unlike molecules. According to these authors, the magnitude of the positive equation values is an excellent indicator of the strength of specific interactions.

Conclusion

The experimental viscosities (η) and molar volumes (Vm) are determined for N-Benzothiazol-2-yl-3, 5-disubstituted pyrazolines in binary mixture from (295.15 K to 305.15 K). From experimental measurements of viscosities (η), molar volumes (Vm) ΔG, ΔH, ΔS, excess parameters equation were calculated. The viscosities and molar volume decreases with increasing temperature and increase with increasing concentration. The study of change in molar volume with respect to change in temperature over the selected range reveals that introduction of solute molecules in binary solvent mixtures decreases with increase in temperature indicating structure breaking property of solute/selected system change in excess viscosity. Deviation of viscosity (Δη) increases with increase in molarity but decrease with increase in temperature. This supports the observation from thermodynamic parameters. That with increase in temperature thermal motion at particles of system increases which results in weakening of solute solvent interaction which in turn causes solvation effect and structural effect.

Acknowledgment

The authors are thankful to the Principal of Shri Shivaji Science College, Amravati for providing research laboratory and necessary things during the research work.

References