Interaction of third-row main group dicarbides, C₂X (X = K-Br) with molecular oxygen: A density functional study

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• 作者：Saroj K. Parida^a ; Sridhar Sahu^a ; ^{sridharsahu@gmail.com" class="auth_mail} ; Sagar Sharma^b
• 关键词：Density functional theory ; Third-row main group dicarbides ; Oxygen adsorption ; ELF ; AIM
• 刊名：Computational and Theoretical Chemistry
• 出版年：15 March, 2014
• 年：2014
• 卷：1032
• 期：Complete
• 页码：1-6
• 全文大小：1116 K

文摘

In this work, we present our calculations, based on density functional theory (DFT) to investigate the molecular adsorption of O₂ on the third-row main group dicarbides, C₂X, with X = K, Ca, Ga, Ge, As, Se, Br. The structures of the host C₂X clusters, except C₂Ga and C₂Ge, are found to be weakly modified in presence of O₂ adsorbate. C₂Ga and C₂Ge clusters which show cyclic ground-state structures become linear while interacting with O₂ molecule. It is observed that the O-O stretching frequencies in C₂XO₂ are red-shifted in comparison to that in O₂ molecule, whereas the C-C stretching frequencies are found to be increased. The calculated adsorption () and Gibbs鈥?free energies (dG) for the clusters with even number of electrons are found to follow the order of C₂CaO₂ > C₂GeO₂ > C₂SeO₂, whereas the increase in O-O bond lengths follows the reverse order, i.e. (O-O)_C2SeO2 > (O-O)_C2GeO2 > (O-O)_C2CaO2. On the other hand, for the clusters with odd number of electrons, and O-O bond lengths follows almost the same order. Existence of disynaptic basins V (C, O) and their corresponding lower relative fluctuation and higher covariance values based on ELF topological analysis infers that the electrons are delocalized in these areas giving rise to shared-electron interactions. In addition, large electron density at the bond critical point (BCP) between C (of host cluster) and O (of adsorbate) also infers the C-O bonding to be shared-type. This fact is also found to be supported by large delocalization index for C and O as compared to that for X and O.