title: Stability of H-complexes of nicotinamide nitrogen heteroatom with water and ethanol in mixed solvents by 13C NMR probing.
abstract: The formation constants of the nicotinamide H-complexes with protonic solvents such as water and ethanol in aqueous dimethyl sulfoxide and aqueous ethanol were determined using (13)C NMR data. Free Gibbs energy of nicotinamide donor center (nitrogen heteroatom) solvation was calculated. Gibbs energy of entire nicotinamide molecule solvation was shown to be antibate towards Gibbs energy of a pyridine nitrogen solvation. The solvation state of this molecule fragment must be taken into consideration when analyzing the reagents contributions in the thermodynamics of complexation.
authors: Ivanovo State University of Chemistry and Technology, F. Engels ave 7, 153000 Ivanovo, Russian Federation.
authors: V A
authors: VA
authors: Sharnin
authors: V V
authors: VV
authors: Aleksandriysky
authors: S V
authors: SV
authors: Dushina
authors: G A
authors: GA
authors: Gamov
mesh_terms: D002247:Carbon Isotopes; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009536:Niacinamide / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D012997:Solvents; D014867:Water; D009536:Niacinamide; D000431:Ethanol; D009584:Nitrogen; D004121:Dimethyl Sulfoxide