Computational design of the magnetism-tunable oligobenzylic carbanion complexes
详细信息 查看全文
- 作者：Hongfang Yang (1)
Jing Zhao (1)
Xinyu Song (1)
Yuxiang Bu (1) - 关键词：2 ; (3 ; 5 ; Dinitrophenyl) ; 1 ; 3 ; dithiane ; based carbanions ; Diradicals ; Tunable magnetic properties ; Antiferromagnetic ; nonmagnetic ; and ferromagnetic characters ; DFT calculations
- 刊名：Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta)
- 出版年：2014
- 出版时间：April 2014
- 年：2014
- 卷：133
- 期：4
- 全文大小：1,135 KB
- 作者单位：Hongfang Yang (1)
Jing Zhao (1)
Xinyu Song (1)
Yuxiang Bu (1)
1. School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China - ISSN：1432-2234
文摘
Unrestricted density functional theory calculations in combination with the broken symmetry approach have been employed to study several benzylic carbanions. As a free anion, 2-(3,5-dinitrophenyl)-1,3-dithiane carbanion has near-degenerate singlet and triplet states and appears to be a promising magnetism-tunable species. In this work, we computationally design some of its derivatives in two ways: expanding the π-conjugated structures and introducing Lewis acids (Li+, Na+, and K+, and polar molecules are considered here) with different acidities. Calculations reveal that ring expansion does not change its open-shell broken symmetry singlet diradical ground state and antiferromagnetic character, but decreases its magnetism, whereas introduction of Lewis acids can lead to different ground states (triplet vs. singlet) and different magnetism, depending on the binding sites of the Lewis acid. That is, they show closed-shell singlet ground states without magnetism when a cation locates near the anionic center of the 1,3-dithiane ring, but convert to triplet as their ground states with ferromagnetic character when the cation moves to one nitro group of the 3,5-dinitrophenyl-based π-conjugation-expanded fragment. These findings regarding modulation through ring expansion and Lewis acid-binding ways make the magnetisms of 2-(3,5-dinitrophenyl)-1,3-dithiane-based carbanions tunable, and thus provide prospects of a new extension of the results from the previous study for designing magnetism-tunable building blocks for novel electromagnetic materials.