All-Atom Force Field for Molecular Dynamics Simulations on Organotransition Metal Solids and Liquids. Application to M(CO)n (M聽= Cr, Fe, Ni, Mo, Ru, or W) Compounds

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• 作者：Carlos E. S. Bernardes ; Jos茅. N. Canongia Lopes ; Manuel E. Minas da Piedade
• 刊名：Journal of Physical Chemistry A
• 出版年：2013
• 出版时间：October 31, 2013
• 年：2013
• 卷：117
• 期：43
• 页码：11107-11113
• 全文大小：245K
• 年卷期：v.117,no.43(October 31, 2013)
• ISSN：1520-5215

文摘

A previously developed OPLS-based all-atom force field for organometallic compounds was extended to a series of first-, second-, and third-row transition metals based on the study of M(CO)_n (M = Cr, Fe, Ni, Mo, Ru, or W) complexes. For materials that are solid at ambient temperature and pressure (M = Cr, Mo, W) the validation of the force field was based on reported structural data and on the standard molar enthalpies of sublimation at 298.15 K, experimentally determined by Calvet-drop microcalorimetry using samples corresponding to a specific and well-characterized crystalline phase: 螖_subH_m^掳 = 72.6 卤 0.3 kJ路mol^鈥? for Cr(CO)₆, 73.4 卤 0.3 kJ路mol^鈥? for Mo(CO)₆, and 77.8 卤 0.3 kJ路mol^鈥? for W(CO)₆. For liquids, where problems of polymorphism or phase mixtures are absent, critically analyzed literature data were used. The force field was able to reproduce the volumetric properties of the test set (density and unit cell volume) with an average deviations smaller than 2% and the experimentally determined enthalpies of sublimation and vaporization with an accuracy better than 2.3 kJ路mol^鈥?. The Lennard-Jones (12-6) potential function parameters used to calculate the repulsive and dispersion contributions of the metals within the framework of the force field were found to be transferable between chromium, iron, and nickel (first row) and between molybdenum and ruthenium (second row).