Aromaticity of the planar quadrilateral CN2O2− dianion in the MCN2O− (M = Li, Na, K, Rb, and Cs) and MCN2O (M = Be, Mg, Ca, Sr, and Ba) clusters

✍ Scribed by Biao Jin; Qiao Jin; Wen Guo Xu

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 584 KB
• Volume: 966
• Category: Article
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2011.01.020

✦ Synopsis

Investigation of equilibrium geometries, total energies, harmonic vibrational frequencies, and nucleusindependent chemical shifts (NICS) of the low-lying states for the planar quadrilateral CN 2 O 2À dianion, alkali metal MCN 2 O À (M = Li, Na, K, Rb, and Cs) clusters, and alkali earth metal MCN 2 O (M = Be, Mg, Ca, Sr, and Ba) clusters were done with two density functional theory (DFT) methods. The calculations reveal that the planar quadrilateral CN 2 O 2À dianion can coordinate with metal atoms to form the pyramidal MCN 2 O À and MCN 2 O complexes maintaining the planar quadrilateral CN 2 O 2À dianion structure.

From structural and electronic criteria, the presence of six delocalized p electrons (satisfying the 4n + 2 electron counting rule), and maintaining its structural and electronic integrity inside the MCN 2 O À and MCN 2 O clusters confirm that the planar quadrilateral CN 2 O 2À dianion exhibits characteristics of paromaticity.