Structural, electronic, thermodynamic and spectral properties of Mgn (n=2–31) clusters. A DFT study

• Published in: Computational and theoretical chemistry Vol. 1079; pp. 34 - 46
• Main Authors: Belyaev, Sergey N., Panteleev, Sergey V., Ignatov, Stanislav K., Razuvaev, Alexey G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2016
• Subjects: Clusters of magnesium; Density functional theory; Grignard reagent; Density functional theory; Grignard reagent; Clusters of magnesium
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2016.01.011

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•The clusters Mg2–Mg31 in singlet and triplet states are studied using the DFT method.•Structural, thermodynamic and spectral parameters of the clusters are studied.•Trends in parameter changes of the growing clusters are discussed.
Small clusters of magnesium Mgn (n=2–31) are of particular interest for coordination chemistry and organometallic chemistry, as they are convenient models of Grignard reagent formation reaction on the surface of activated metallic magnesium, and also are directly involved in this reaction under vacuum atomized state conditions. In this study, the structure, thermodynamic functions (total energy, enthalpy and Gibbs free energy of formation of Mgn systems), and the electronic parameters (dipole moments, band-gap energy, distribution of partial atomic charges) for optimized clusters were investigated using the density functional theory (B3PW91/6-31G (d), B3PW91/6-311+G (2d)). The energies and thermodynamic functions of cluster atomization and isomerization, energies of S0→T1 singlet-triplet transitions, and energies of separation of single or multiple magnesium atoms from clusters, which are described within the framework of simple statistical models, were determined. The calculated parameters allow to estimate the properties of the clusters whose structure corresponds to different centers of magnesium surface involved in Grignard reagent formation reaction, and therefore, to estimate their contribution to reactivity. The calculated Mg2–Mg31 IR spectra enable identification of individual clusters under experimental conditions.