Abstract
The enthalpies of mixing for model protein compounds (glycine, alanine, N,N-dimethyl formamide (DMF) and N,N-dimethyl acetamide (DMA)) with diols (1, 3-butanediol and 2, 3-butanediol) and their respective enthalpies of dilution in aqueous solutions at 310.15 K were determined by flow microcalorimetric measurements. Heterotactic enthalpic interaction coefficients (hxy, hxxy, hxyy) were obtained by analyzing these experimental results according to McMillan-Mayer theory. The results indicated that the hxy values were all positive with a dominant endothermic effect and the coefficients decreased according to the order of hxy(DMA)hxy(Ala)hxy(Gly)hxy(DMF) and hxy(2,3-butanediol) hxy(1,3-butanediol). Based on these results, we discussed solute-solute and solute-solvent interactions with regards to the influence of the relative position of the diol functional groups on the value of hxy. We found that the hydrogen bonds between DMF or DMA and the diols were strong, and because of the good polarizability of DMF′s resonance structure, hydrogen bonds between DMF and the diols were further strengthened.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.