Experimental and molecular dynamics simulation study of the sublimation energetics of cyclopentadienyltricarbonylmanganese (Cymantrene).
The standard molar enthalpy of sublimation of monoclinic cyclopentadienyltricarbonylmanganese, Mn(eta (5)-C 5H 5)(CO) 3, at 298.15 K, was determined as Delta sub H m (o)[Mn(eta (5)-C 5H 5)(CO) 3] = 75.97 +/- 0.37 kJ x mol (-1) from Knudsen effusion and Calvet-drop microcalorimetry measurements, thus considerably improving the very large inaccuracy (>10 kJ x mol (-1)) of the published data. The obtained value was used to assess the extension of the OPLS-based all-atom force field we previously developed for iron metallocenes to manganese organometallic compounds. The modified force field was able to reproduce the volumetric properties (density and unit-cell volume) of crystalline Mn(eta (5)-C 5H 5)(CO) 3 with a deviation of 0.6% and the experimentally determined enthalpy of sublimation with an accuracy of 1 kJ x mol (-1). The interaction (epsilon) and atomic-diameter (sigma) parameters of the Lennard-Jones (12-6) potential function used to calculate dispersion contributions within the framework of the force field were found to be transferable from iron to manganese.
Picciochi
Ricardo
R
Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1649-016 Lisboa, Portugal.
Canongia Lopes
José N
JN
Diogo
Hermínio P
HP
Minas da Piedade
Manuel E
ME
D002151:Calorimetry; D003198:Computer Simulation; D007501:Iron / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D044367:Phase Transition; D013816:Thermodynamics
D009942:Organometallic Compounds; D008345:Manganese; D007501:Iron; C044679:manganese cyclopentadienyl tricarbonyl