Theoretical study on the two novel planar-type all-nitrogen N44− anions: Structures, stability, reaction rate and their stable mechanisms via protonation

• Published in: Chemical physics letters 2021-05, Vol.771, p.138519, Article 138519
• Main Authors: Feng, Yifan, Zhu, Haiyan, Zhang, Qiyan, Zhao, Qinfu, Zhao, He, Suo, Bingbing, Zhai, Gaohong, Zou, Wenli, Han, Huixian, Song, Qi, Li, Jianfu, Li, Yawei
• Format: Article
• Language: English
• Subjects: DFT; N44− anions; N4H4; Protonation; Stability
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2021.138519

Two novel N44− anions with planar zigzag and tripod structures were obtained, respectively. The lightest hydrogen cations (H+) are selected to saturate the N44− anions to form neutral N4H4 molecules, and the further calculated results showed that the N4H4 have excellent kinetic stability. Moreover, the existing conditions of and N4H4 were predicted, discovering that the N4H4 molecules could remain stable at ambient condition. [Display omitted] •Two novel N44− anions with planar zigzag and tripod structures are revealed, respectively.•The stability of the N44− structures is remarkably improved after protonation.•The N4H4 molecules with tripod and zigzag structures could remain stable at ambient conditions. Using an unbiased structural search based on a particle-swarm optimization algorithm, two novel N44− anions with planar zigzag and tripod structures were revealed, respectively. Their structures, bonding patterns and charge populations have been theoretically studied. Moreover, H+ cations were selected to saturate the N44− anions to form neutral N4H4 molecules, and the further calculated results showed that the N4H4 compounds have higher kinetic stability than the corresponding N44− anions. Subsequently, the reaction rate calculations also indicated that the N4H4 molecules could remain stable at ambient conditions.