Dilution Enthalpies and Enthalpic Pairwise Self-Interactions of Nicotinamide and Isonicotinamide in (Dimethylformamide plus Water) and (Dimethyl Sulfoxide plus Water) Mixed Solvents at 298.15 K

作者：Chen Nan; Jia Zhao Peng; Wang Hua Qin; Zhu Li Yuan; Hu Xin Gen^*

来源：Journal of Chemical and Engineering Data, 2014, 59(7): 2324-2335.

DOI：10.1021/je500447r

The dilution enthalpies of nicotinamide (NA) and isonicotinamide (INA) in (dimethyl sulfoxide (DMSO) + water) and (dimethylformamide (DMF) + water) mixed solvents (M1 and M2) at 298.15 K have been determined, respectively, using an isothermal titration calorimeter (MicroCal ITC200). On the basis of the McMillan-Mayer theory, enthalpic pairwise self-interaction coefficients (h(xx)) of NA and INA in both M1 and M2 aqueous mixed solvents (mole fractions of cosolvents x(cos) = 0 to 0.10) have been calculated. It was found that the values of hxx are all large negative, with the relative magnitudes h(xx)(NA) < h(xx)(INA) < 0 in both M1 and M2, and h(xx)(in M1) > h(xx) (in M2) for both NA and INA, and that all of them increase monotonously with the concentrations of cosolvents (both DMF and DMSO). It implies that an intense exothermic effect accompanies with the pairwise hydrophilic-hydrophilic self-interactions, in which the meso-isomer (NA) behaves as a stronger molecular associator than the para-isomer (INA).

• 出版日期2014-7
• 单位温州大学