Planar Pentacoordinate Nitrogen in a Pseudo-Double-Aromatic NBe5H4+ Cluster

Kalita, Amlan J.; Rohman, Shahnaz S.; Kashyap, Chayanika; Ullah, Sabnam S.; Baruah, Indrani; Guha, Ankur K.

doi:10.1021/acs.inorgchem.0c03045

Cited by 16 publications

(11 citation statements)

References 54 publications

(62 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The rule-breaking bonding usually requiring new considerations upon classical bonding models, especially an effective electronic design scheme, is a key issue to excavate them. − The highly delocalized bonding originating from the active participation of p/d π electrons of the central atom has been proven to facilitate planar hypercoordinate main-group/transition metals. − For instance, the fully delocalized π electrons of the central p z lone pair reinforced by π-acceptor/σ-donor ligands can effectively stabilize the high-symmetry planar hypercoordinate carbon or other main-group atoms, making the mixed π/σ-aromatic species according to the 4 n + 2 rule. − The dual σ + π aromaticity is responsible for highly stable transition-metal-centered borometallic molecular wheels. ,− It is worth noting that the σ aromaticity alone has been found to provide a crucial electronic stabilization factor for planar hypercoordinate clusters, but it is limited to transition metals. − …”

mentioning

confidence: 99%

“…The valence population of ppBe is given in Table S1, and the negligible p z occupations of the ppBe and M atoms in BeM 5 + are clearly different from those of π-delocalized planar hypercoordinate species, − ,− where the high p z occupations originating from the effective p z lone-pair π electrons of the central atoms are of importance electronically to support their stability and planarity. The high s occupations of the ppBe and M atoms, and the considerable p x and p y occupations of the ppBe atom both reveal that the pronounced σ delocalization rather than π delocalization is a main bonding picture in BeM 5 + .…”

mentioning

confidence: 99%

See 1 more Smart Citation

σ-Aromaticity Planar Pentacoordinate Beryllium Atoms

2021

View full text Add to dashboard Cite

Six-valence-electron planar pentacoordinate beryllium (ppBe) is explored herein as a global minimum, which is only constructed by s-block metals in BeM 5 + (M = Cu, Ag, Au). The bonding in ppBe can be regarded as the excited-stated Be with a 2p x 1 2p y 1 electronic configuration, forming electron sharing with doublet M 5 + motifs followed by two sets of Be(p ∥ ) → [M 5 + ] σ donations and one Be(s) ← [M 5 + ] σ back-donation. Thus, the σ aromaticity originating from three delocalized σ orbitals gives rise to the whole stability of the high D 5h -symmetry ppBe and strongly enriches s-block planar hypercoordinate bonding.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

σ-Aromaticity Planar Pentacoordinate Beryllium Atoms

2021

View full text Add to dashboard Cite

show abstract

“…Since then, many molecules containing ptC have been characterized in silico [23][24][25][26][27][28][29][30][31][32], and some have been experimentally detected [1][2][3][4][5][6][7][8][9]. Lately, the idea of ptC has been extended to planar hypercoordinate carbon (phC; penta [33][34][35] and hexa [36][37][38][39][40] coordination) as well as to other elements such as B [41,42] or N [43] considering their potential applications in material science [44,45].…”

Section: Introductionmentioning

confidence: 99%

CAl4Mg0/−: Global Minima with a Planar Tetracoordinate Carbon Atom

Job

Khatun

Thirumoorthy

et al. 2021

Atoms

View full text Add to dashboard Cite

Isomers of CAl4Mg and CAl4Mg− have been theoretically characterized for the first time. The most stable isomer for both the neutral and anion contain a planar tetracoordinate carbon (ptC) atom. Unlike the isovalent CAl4Be case, which contains a planar pentacoordinate carbon atom as the global minimum geometry, replacing beryllium with magnesium makes the ptC isomer the global minimum due to increased ionic radii of magnesium. However, it is relatively easier to conduct experimental studies for CAl4Mg0/− as beryllium is toxic. While the neutral molecule containing the ptC atom follows the 18 valence electron rule, the anion breaks the rule with 19 valence electrons. The electron affinity of CAl4Mg is in the range of 1.96–2.05 eV. Both the global minima exhibit π/σ double aromaticity. Ab initio molecular dynamics simulations were carried out for both the global minima at 298 K for 10 ps to confirm their kinetic stability.

show abstract

“…In the last five decades, a large array of molecules containing ptC atoms that are global and local minima were computationally identified [10,14,15,[46][47][48][49][50][51][52][53][54][55][56][57][58], and some were experimentally detected [5,[26][27][28][29][30][31][32][33]59]. Lately, the idea of ptC has been extended to planar hypercoordinate carbon (phC; Penta [60][61][62][63][64][65][66] and Hexa [67][68][69][70][71] coordination) and also to other elements such as B [72][73][74][75] or N [76] considering their potential applications in material science [77,78].…”

Section: Introductionmentioning

confidence: 99%

BAl4Mg−/0/+: Global Minima with a Planar Tetracoordinate or Hypercoordinate Boron Atom

Khatun

Roy

Giri

et al. 2021

Atoms

View full text Add to dashboard Cite

We have explored the chemical space of BAl4Mg−/0/+ for the first time and theoretically characterized several isomers with interesting bonding patterns. We have used chemical intuition and a cluster building method based on the tabu-search algorithm implemented in the Python program for aggregation and reaction (PyAR) to obtain the maximum number of possible stationary points. The global minimum geometries for the anion (1a) and cation (1c) contain a planar tetracoordinate boron (ptB) atom, whereas the global minimum geometry for the neutral (1n) exhibits a planar pentacoordinate boron (ppB) atom. The low-lying isomers of the anion (2a) and cation (3c) also contain a ppB atom. The low-lying isomer of the neutral (2n) exhibits a ptB atom. Ab initio molecular dynamics simulations carried out at 298 K for 2000 fs suggest that all isomers are kinetically stable, except the cation 3c. Simulations carried out at low temperatures (100 and 200 K) for 2000 fs predict that even 3c is kinetically stable, which contains a ppB atom. Various bonding analyses (NBO, AdNDP, AIM, etc.) are carried out for these six different geometries of BAl4Mg−/0/+ to understand the bonding patterns. Based on these results, we conclude that ptB/ppB scenarios are prevalent in these systems. Compared to the carbon counter-part, CAl4Mg−, here the anion (BAl4Mg−) obeys the 18 valence electron rule, as B has one electron fewer than C. However, the neutral and cation species break the rule with 17 and 16 valence electrons, respectively. The electron affinity (EA) of BAl4Mg is slightly higher (2.15 eV) than the electron affinity of CAl4Mg (2.05 eV). Based on the EA value, it is believed that these molecules can be identified in the gas phase. All the ptB/ppB isomers exhibit π/σ double aromaticity. Energy decomposition analysis predicts that the interaction between BAl4−/0/+ and Mg is ionic in all these six systems.

show abstract

Planar Pentacoordinate Nitrogen in a Pseudo-Double-Aromatic NBe₅H₄⁺ Cluster

Abstract: High-level quantum-chemical calculations have been used to predict a cationic ternary NBe5H4 + cluster containing a planar pentacoordinate nitrogen atom. The proposed cluster has pseudo dual aromaticity and is kinetically and thermodynamically very stable.

Cited by 16 publications

References 54 publications

σ-Aromaticity Planar Pentacoordinate Beryllium Atoms

σ-Aromaticity Planar Pentacoordinate Beryllium Atoms

CAl4Mg0/−: Global Minima with a Planar Tetracoordinate Carbon Atom

BAl4Mg−/0/+: Global Minima with a Planar Tetracoordinate or Hypercoordinate Boron Atom

Contact Info

Product

Resources

About