1
|
Jin B, Yuan C, Guo JC, Wu YB. CBe 4H 6: a molecular rotor with a built-in on-off switch. NANOSCALE 2024; 16:4778-4786. [PMID: 38305072 DOI: 10.1039/d3nr05695c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
It is highly challenging to control (stop and resume as needed) molecular rotors because their intramolecular rotations are electronically enabled by delocalized σ bonding, and the desired control needs to be able to destroy and restore such σ bonding, which usually means difficult chemical manipulation (substitution or doping atom). In this work, we report CBe4H6, a molecular rotor that can be controlled independently of chemical manipulation. This molecule exhibited the uninterrupted free rotation of Be and H atoms around the central carbon in first-principles molecular dynamics simulations at high temperatures (600 and 1000 K), but the rotation cannot be witnessed in the simulation at room temperature (298 K). Specifically, when a C-H bond in the CBe4H6 molecule adopts the equatorial configuration at 298 K, it destroys the central delocalized σ bonding and blocks the intramolecular rotation (the rotor is turned "OFF"); when it can adopt the axial configuration at 600 and 1000 K, the central delocalized σ bonding can be restored and the intramolecular rotation can be resumed (the rotor is turned "ON"). Neutral CBe4H6 is thermodynamically favorable and electronically stable, as reflected by a wide HOMO-LUMO gap of 7.99 eV, a high vertical detachment energy of 9.79 eV, and a positive electron affinity of 0.24 eV, so it may be stable enough for the synthesis, not only in the gas phase, but also in the condensed phase.
Collapse
Affiliation(s)
- Bo Jin
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China.
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
| | - Caixia Yuan
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China.
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China
| | - Jin-Chang Guo
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China.
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China
| | - Yan-Bo Wu
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China.
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, People's Republic of China
| |
Collapse
|
2
|
Jin B, Wang ZR, Wu YB. Tetracoordinate or tricoordinate? Planar tetracoordinate nitrogen in the NBe4H4- cluster stabilized by multicenter bonds. J Chem Phys 2024; 160:054304. [PMID: 38341688 DOI: 10.1063/5.0188035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 01/15/2024] [Indexed: 02/13/2024] Open
Abstract
Realization of planar tetracoordinate arrangements of nitrogen atoms is challenging because their preference for localized bonding (caused by its high electronegativity) makes them typically tricoordinate. This is especially true for the more electronegative oxygen atoms. Herein, we computationally designed two clusters NBe4H4- and OBe4H4; they contain a planar tetracoordinate nitrogen (ptN) and planar tetracoordinate oxygen (ptO) atom, respectively. Remarkably, the former is a dynamically stable global minimum, while the latter is not. The bonding analysis proves that planar tetracoordination in NBe4H4- favors over tricoordination because of the presence of multicenter delocalized bonds. In contrast, the planar tricoordination dominates due to its weak delocalized bonding ability of oxygen in the OBe4H4 cluster. Moreover, the 6σ/2π double aromaticity due to multicenter delocalized bonds allows the NBe4H4- cluster to obtain additional stability. This cluster is a promising synthetic due its dynamic and thermodynamic stability.
Collapse
Affiliation(s)
- Bo Jin
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou 034000, Shanxi, People's Republic of China
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi, People's Republic of China
| | - Zai-Ran Wang
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou 034000, Shanxi, People's Republic of China
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi, People's Republic of China
| | - Yan-Bo Wu
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi, People's Republic of China
| |
Collapse
|
3
|
Guan XL, Sun R, Jin B, Yuan C, Wu YB. 3-D molecular stars with covalent axial bonding. J Comput Chem 2023; 44:1410-1417. [PMID: 36872591 DOI: 10.1002/jcc.27096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 03/07/2023]
Abstract
In designing three-dimensional (3-D) molecular stars, it is very difficult to enhance the molecular rigidity through forming the covalent bonds between the axial and equatorial groups because corresponding axial groups will generally break the delocalized π bond over equatorial frameworks and thus break their star-like arrangement. In this work, exemplified by designing the 3-D stars Be2 ©Be5 E5 + (E = Au, Cl, Br, I) with three delocalized σ bonds and delocalized π bond over the central Be2 ©Be5 moiety, we propose that the desired covalent bonding can be achieved by forming the delocalized σ bond(s) and delocalized π bond(s) simultaneously between the axial groups and equatorial framework. The covalency and rigidity of axial bonding can be demonstrated by the total Wiberg bond indices of 1.46-1.65 for axial Be atoms and ultrashort Be-Be distances of 1.834-1.841 Å, respectively. Beneficial also from the σ and π double aromaticity, these mono-cationic 3-D molecular stars are dynamically viable global energy minima with well-defined electronic structures, as reflected by wide HOMO-LUMO gaps (4.68-5.06 eV) and low electron affinities (4.70-4.82 eV), so they are the promising targets in the gas phase generation, mass-separation, and spectroscopic characterization.
Collapse
Affiliation(s)
- Xiao-Ling Guan
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan, China.,Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan, China
| | - Rui Sun
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan, China.,Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan, China
| | - Bo Jin
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan, China.,Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan, China
| | - Caixia Yuan
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan, China.,Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan, China
| | - Yan-Bo Wu
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan, China.,Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan, China
| |
Collapse
|
4
|
Jia XD, Du ZW. 18-valence-electron rule lighted planar tetracoordinate carbon and nitrogen: the global energy minima of CAl 4Zn and NAl 4Zn . Phys Chem Chem Phys 2023; 25:4211-4215. [PMID: 36655923 DOI: 10.1039/d2cp04743h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The exploration of planar hypercoordinate carbon (phC) is challenging and significant. It is often puzzling to chemists whether the designed phC species should satisfy the 18-valence-electron rule, an authoritative rule in the phC field. In this study, we introduced a zinc atom into the extremely unstable 16-valence-electron planar tetracoordinate carbon (ptC) species CAl4 and its isoelectronic structure NAl4+ with a planar tetracoordinate nitrogen (ptN), and designed the 18-valence-electron CAl4Zn and NAl4Zn+ possessing a ptC and ptN, respectively. The thermodynamic results indicate that the ptC/N species CAl4Zn and NAl4Zn+ are the global energy minima, and also showed that the 18-valence-electron rule is more appropriate in designing ptC/N species having the CAl4 and NAl4+ skeletons, compared with the 16-valence-electron rule. Simultaneously, the BOMD simulations found that CAl4Zn is dynamically stable. Although NAl4Zn+ was isomerized at 298 and 500 K, it is dynamically viable. The excellent stability may be explained by the perfect electronic structure. First, the HOMO-LUMO gaps became much wider after the introduction of the Zn atom. Second, AdNDP analysis indicated that the introduction of the Zn atom promoted the formation of peripheral Al-Al and Al-Zn covalent bonds, providing a stable and comfortable bonding environment for ptC/N. In addition, the σ and π double aromaticity further stabilized the ptC/N species. Hence, as dynamic global energy minima display σ and π double aromaticity, the ptC/N species CAl4Zn and NAl4Zn+ are promising in gas phase generation.
Collapse
Affiliation(s)
- Xiu-Dong Jia
- Institute of Molecular Science, Shanxi University, Taiyuan, 030006, People's Republic of China.
| | - Zhi-Wei Du
- School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, People's Republic of China
| |
Collapse
|