Portal de Periódicos da CAPES

Surprises with strain energy and sulpholane (tetrahydrothiophene 1,1-dioxide): a combined experimental and theoretical investigation

2004; Taylor & Francis; Volume: 102; Issue: 5 Linguagem: Inglês

10.1080/002689710410001671558

1362-3028

Victor M.F. Morais, M. Agostinha R. Matos, Margarida S. Miranda, Joel F. Liebman,

thermodynamics and calorimetric analyses

Abstract The standard molar enthalpy of formation for liquid sulpholane was derived from the standard molar enthalpy of combustion, in oxygen at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpy of vaporization, at T = 298.15 K, was measured by Calvet microcalorimetry. The results are: ; ; and . Additionally, high-level density functional theory calculations using the B3LYP hybrid exchange-correlation energy functional have been performed for sulpholane in order to obtain its geometry, enthalpy of formation in the gaseous phase and strain energy. Acknowledgements Thanks are due to Fundação para a Ciência e a Tecnologia, FCT, Lisbon, Portugal, and for financial support to Centro de Investigação em Química of the University of Porto. M. S. Miranda thanks the FCT for the award of her postdoctoral scholarship (BPD/5594/2001). Notes †Given the thermochemical interests of the current authors, we note that calorimetry was useful in the understanding of the structure and activity of penicillin. Woodward et al. [Citation7] reported the enthalpy of formation of pencillin and also that of the monocyclic thiazolidine formed by methanolysis. Comparing these values to those of a simpler monocyclic β-lactam and its ring-opened 2-aminopropanoic acid derivative helped to confirm the currently accepted structure for pencillin.