title: A Raman study on preferential interactions in the formamide/pyridine/pyridazine system and complementary thermodynamic information on the formamide/pyridazine mixture.
abstract: The formamide (FA)/pyridine (py)/pyridazine (prd) system was investigated by FT-Raman spectroscopy and the results in situ show that FA is preferentially bound to py, as experimentally pointed out by the proton affinity (PA) values of these azabenzenes. Temperature-dependent further investigations for the FA/prd mixture clearly show that the 2:1 FA:prd complex is more stable than the 1:1 FA:py adduct, even though its formation is influenced by the extremely negative entropy of the system, which becomes the spontaneously unfavorable global process. Linear relationships of the complex formation enthalpies (ΔH°) with band shifts (Δν) and dipole moments (μ) of these azabenzenes are observed and are in excellent agreement with our recent studies.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465/Km 7, Seropédica, RJ 23890-000, Brazil.
authors.forename: Elaine F
authors.initials: EF
authors.lastname: da Silva
authors.forename: Wagner A
authors.initials: WA
authors.lastname: Alves
mesh_terms: D001665:Binding Sites; D005559:Formamides / Q000737:chemistry*; D011522:Protons; D011724:Pyridazines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics
chemical_list: D005559:Formamides; D011522:Protons; D011724:Pyridazines; D011725:Pyridines; C062482:pyridazine; C031066:formamide; C023666:pyridine