Theoretical Study of closo-Borate Anions [BnHn]2− (n = 5–12): Bonding, Atomic Charges, and Reactivity Analysis

Abstract

This study has focused on the structure, bonding, and reactivity analysis of closo-borate anions [BnHn]2− (n = 5–12). Several descriptors of B–H interactions have been calculated. It has been found that the values of electron density and total energy at bond critical point are the most useful descriptors for investigation of B–H interactions. Using results from the descriptor analysis, one may conclude that orbital interactions in [BnHn]2− increase with increasing the boron cluster size. Several approaches to estimate atomic charges have been applied. Boron atoms in apical positions have more negative values of atomic charges as compared with atoms from equatorial positions. The mean values of boron and hydrogen atomic charges tend to be more positive with the increasing of boron cluster size. Global and local reactivity descriptors using conceptual density functional theory (DFT) theory have been calculated. Based on this theory, the closo-borate anions [BnHn]2− (n = 5–9) can be considered strong and moderate electrophiles, while the closo-borate anions [BnHn]2− (n = 10–12) can be considered marginal electrophiles. Fukui functions for electrophilic attack have been calculated. Fukui functions correlate well with atomic charges of the closo-borate anions. Boron atoms in apical positions have the most positive values of Fukui functions.

Nucleophilic addition reactions to nitrilium derivatives [B12H11NCCH3]− and [B12H11NCCH2CH3]−. Synthesis and structures of closo-dodecaborate-based iminols, amides and amidines

“…It should be noted that a series of closo-dodecaborate based iminols were recently obtained via the Pd-catalyzed microwaveassisted cross-coupling reaction of [B 12 H 11 I] 2− with amides. 40 The subsequent treatment of the obtained iminols [3](NHEt 3 ) and [4] [6](NHEt 3 ) 2 in quantitative yields (Scheme 3). Thus, we performed the reactions from the nitrilium derivatives to the amides via the iminol formation.…”

“…Investigations of such a unique compound revealed an aromatic character that is considered as three-dimensional aromaticity, which is a cause of its exceptionally high thermal, chemical and electrochemical stability. [1][2][3] This exceptional stability together with the unique properties of the borohydride opens ways to the practical use of [B 12 H 12 ] 2− in fields of coordination chemistry, [4][5][6] ligand design, [7][8][9] catalysis, [10][11][12] and supramolecular chemistry, 13,14 but the most known is its application in medicinal chemistry as the BNCT agent. [15][16][17][18][19][20] As a rule, many applications of [B 12 H 12 ] 2− require the introduction of substituents into symmetrical electron-delocalized clusters.…”

“…NH 2 Et 2 : 1 H-NMR (acetonitrile-d 3 , ppm): δ 5.89 (broad s, 1H, BNH), 3.37 (broad m, 4H, CNCH 2 CH 3 ), 3.07 (q, J = 7 3. Hz, 4H, H 2 NCH 2 CH 3 ), 2.50 (s, 3H, CH 3 ), 1.27 (t, J = 7.3 Hz, 6H, H 2 NCH 2 CH 3 ), 1.17 (t, J = 7.2 Hz, 6H, CNCH 2 CH 3 ).…”

Electronic and Optical Properties of Atomic-Scale Heterostructure Based on MXene and MN (M = Al, Ga): A DFT Investigation

“…where that the framework of the quantum theory of atoms in molecules (QTAIM) functional is not considered here, which is also a popular method for simulations [90][91][92][93][94][95][96][97][98][99]. The results show that the Hf2CO2/MN heterostructure is formed by vdW interactions [100,101].…”

“…MXene/MN , E MXene and E MN show the total energy of the Hf 2 CO 2 /MN heterostructure, monolayered Hf 2 CO 2 and MN, respectively. The smaller the binding energy, the more stable the structure of the heterostructure[89], and thus the most stable structure of those six stacking configurations of the heterostructure is decided as the lowest binding energy, which is demonstrated in the AA stacking style of the Hf 2 CO It is worth not-ing that the framework of the quantum theory of atoms in molecules (QTAIM) functional is not considered here, which is also a popular method for simulations[90][91][92][93][94][95][96][97][98][99]. The results show that the Hf 2 CO 2 /MN heterostructure is formed by vdW interactions[100,101].…”