Structural, energetic and reactivity properties of phenoxazine and phenothiazine
authors Freitas, VLS; Gomes, JRB; da Silva, MDMCR
nationality International
journal JOURNAL OF CHEMICAL THERMODYNAMICS
author keywords Enthalpies of formation and transition phase; Vapor pressures; Electrostatic potential energy maps; HOMO and LUMO; N-H bond dissociation enthalpies; Gas-phase acidities and basicities
keywords DIFFERENTIAL SCANNING CALORIMETERS; FLUORESCENT STAIN; THERMOCHEMISTRY; CALIBRATION; ENTHALPIES; HEAT; SUBLIMATION; DERIVATIVES; COMBUSTION; ENERGIES
abstract A combined experimental and computational study was developed with the aim of evaluate and understand the structural, energetic and reactivity properties of phenoxazine and phenothiazine. Experimentally, differential scanning calorimetry, static and rotating bomb combustion calorimetries, Knudsen effusion and Calvet microcalorimetry were employed to determine, respectively, the standard (p degrees = 0.1 MPa) molar enthalpies of fusion, Delta H-1(cr)m degrees, at the temperature of fusion, the standard molar enthalpies of formation, in the crystalline phase, Delta H-f(m)degrees(cr), at T = 298.15 K, the temperature-vapor pressures dependences, and the standard molar enthalpies of sublimation, Delta H-g(cr)m degrees, at T = 298.15 K. These data allowed the derivation the experimental standard molar enthalpies of formation, in the gaseous phase, Delta H-f(m)degrees(g), of phenoxazine, (100.8 +/- 4.3) kJ.mol (1), and of phenothiazine, (273.5 +/- 4.7) kJ.mol (1). Computationally, the composite G3(MP2)//B3LYP approach was used to optimize the structures of these two compounds and to estimate their Delta H-f(m)degrees(g) values, which are found to be in very good agreement with the experimental ones. Calculations were also performed for additional analyses of their natural bond orbitals (NBO) and to obtain other gas-phase thermodynamic properties, namely N-H bond dissociation enthalpies, gas-phase acidities and basicities and proton affinities. (C) 2013 Elsevier Ltd. All rights reserved.
publisher ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
issn 0021-9614
year published 2014
volume 73
beginning page 110
ending page 120
digital object identifier (doi) 10.1016/j.jct.2013.11.013
web of science category Thermodynamics; Chemistry, Physical
subject category Thermodynamics; Chemistry
unique article identifier WOS:000335846900017
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 2.631
5 year journal impact factor 2.531
category normalized journal impact factor percentile 63.559
dimensions (citation analysis):
altmetrics (social interaction):



 


Apoio

1suponsers_list_ciceco.jpg