title: Positive and Negative Contributions in the Solvation Enthalpy due to Specific Interactions in Binary Mixtures of C1-C4 n-Alkanols and Chloroform with Butan-2-one.
abstract: In the paper, results of calorimetric measurements, IR spectra, and calculated ab initio stabilization energies of dimers are reported for binary systems butan-2-one + (methanol, ethanol, propan-1-ol, butan-1-ol, and chloroform). Changes in the total enthalpy of specific interactions due to dissolution of butan-2-one in the alcohols, calculated using equations derived in previous works, are positive. That results from the endothermic breaking of the O-H···O-H bonds not completely compensated by the exothermic effects of formation of the O-H···O═C ones. Moreover, the concentration of nonbonded molecules of butan-2-one is significant even in dilute solutions, as is evidenced by the shape of the C═O stretching vibrations band in the IR spectra. Apart from that, the spectra do not confirm 1:2 complexes in spite of two lone electron pairs in the carbonyl group of butan-2-one capable of forming the hydrogen bonds. The changes in enthalpy of specific interactions are negative for dilute solutions of alcohols and chloroform in butan-2-one and of butan-2-one in chloroform, because no hydrogen bonds occur in pure butan-2-one. The experimental results are positively correlated with the enthalpies estimated from the ab initio energies using a simple "chemical reaction" approach.
authors.affiliation: †Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russian Federation.
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Varfolomeev
authors.affiliation: †Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russian Federation.
authors.forename: Ilnaz T
authors.initials: IT
authors.lastname: Rakipov
authors.affiliation: †Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russian Federation.
authors.forename: Boris N
authors.initials: BN
authors.lastname: Solomonov
authors.affiliation: ‡Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Lodowski
authors.affiliation: †Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russian Federation.|§Institute of Occupational Medicine and Environmental Health, Kościelna 13, 41-200 Sosnowiec, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Marczak
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D002074:Butanones / Q000737:chemistry*; D002151:Calorimetry; D002725:Chloroform / Q000737:chemistry*; D019281:Dimerization; D006860:Hydrogen Bonding; D008956:Models, Chemical; D012996:Solutions; D012997:Solvents / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D000438:Alcohols; D002074:Butanones; D012996:Solutions; D012997:Solvents; D002725:Chloroform