Excess molar enthalpies (H_{\mathrm{m}}^{\mathrm{E}}) and excess molar heat capacities (C_{\rho, \mathrm{m}}^{\mathrm{E}}) of (\left[x \mathrm{CF}{3} \mathrm{CH}{2} \mathrm{OH}+\right.) ((1-x)\left{\mathrm{HCON}\left(\mathrm{CH}{3}\right){2}\right.) or (\left.\left.\mathrm{CH}{3} \mathrm{CN}\right}\right]) were measured at the temperature (T=298.15 \mathrm{~K}). For the former, (H{\mathrm{m}}^{\mathrm{E}}) was as negative as (H_{\mathrm{m}}^{\mathrm{E}}\left{x \mathrm{CF}{3} \mathrm{CH}{2} \mathrm{OH}+(1-x)\left(\mathrm{CH}{3}\right){2} \mathrm{SO}\right},{ }^{(1)}) because of the formation of more stable hydrogen bonds between unlike molecules than those between (\mathrm{CF}{3} \mathrm{CH}{2} \mathrm{OH}) molecules. The minimum was (-3400 \mathrm{~J} \cdot \mathrm{mol}^{-1}) at (x=0.55). For the latter, (H_{\mathrm{m}}^{\mathrm{E}}) changes sign from positive for (x<0.67) to negative for (x>0.67); its minimum was (-185 \mathrm{~J} \cdot \mathrm{mol}^{-1}) at (x=0.87) and its maximum (+180 \mathrm{~J} \cdot \mathrm{mol}^{-1}) at (x=0.33). For both mixtures (C_{p, \mathrm{~m}}^{\mathrm{E}}) was large and negative; for the former, the minimum was (-15 \mathrm{~J} \cdot \mathrm{K}^{-1} \cdot \mathrm{mol}^{-1}) at (x=0.66) and for the latter, (-9 \mathrm{~J} \cdot \mathrm{K}^{-1} \cdot \mathrm{mol}^{-1}) at (x=0.55). The new pair interaction was considered to be the more flexible and difficult to break the higher the temperature than the interactions in the pure substances, as previously found for (\left{x \mathrm{CF}{3} \mathrm{CH}{2} \mathrm{OH}+(1-x)\left(\mathrm{CH}{3}\right){2} \mathrm{SO}\right}).