Comparative studies on group III σ-hole and π-hole interactions

Abstract

The σ-hole of M2 H6 (M = Al, Ga, In) and π-hole of MH3 (M = Al, Ga, In) were discovered and analyzed, the bimolecular complexes M2 H6 ···NH3 and MH3 ···N2 P2 F4 (M = Al, Ga, In) were constructed to carry out comparative studies on the group III σ-hole interactions and π-hole interactions. The two types of interactions are all partial-covalent interactions; the π-hole interactions are stronger than σ-hole interactions. The electrostatic energy is the largest contribution for forming the σ-hole and π-hole interaction, the polarization energy is also an important factor to form the M···N interaction. The electrostatic energy contributions to the interaction energy of the σ-hole interactions are somewhat greater than those of the π-hole interactions. However, the polarization contributions for the π-hole interactions are somewhat greater than those for the σ-hole interactions.

Should “anion–π interactions” be called “anion–σ interactions”? A revision of the origin of some hole-bonds and their nomenclature

“…NCIs to electrostatic holes at B901 of the covalent bond). 1,10,[12][13][14][15][16][17][18] Double bonds with electronegative atoms enhance the p-hole (compare ethene and formaldehyde ESPs, Fig. 1B and D), but single bonds with specific electronegative groups may also enhance the same hole: carbonyl difluoride (Fig.…”

Competition between Intra and Intermolecular Triel Bonds. Complexes between Naphthalene Derivatives and Neutral or Anionic Lewis Bases

“…As triel (Tr) atoms (B, Al, etc) typically find themselves in planar TrR 3 molecular arrangements, a π-hole can be found above and below this atom, which facilitates the formation of a triel bond (TrB) with an approaching nucleophile. There are also exceptional cases wherein a tetravalent Tr atom can generate a σ-hole [57]. This TrB has generated sufficient interest so as to be the focus of a number of prior quantum chemical studies [58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73].…”

On the ability of pnicogen atoms to engage in both σ and π-hole complexes. Heterodimers of ZF2C6H5 (Z = P, As, Sb, Bi) and NH3

“…These π-holes have been identified in numerous molecules, such as carbonyls, trisubstituted centers, and nitro-and acyl-carbon-containing entities [40,45,46]. The ensuing π-hole interactions share many of the same features with their σ-hole cousins [47] and can be responsible for even stronger bonds [48]. Although the study of π-hole interactions is accelerating, direct comparisons of σ-This paper is dedicated to Zdzisław Latajka, honoring his many contributions to chemistry, on the occasion of his retirement.…”

“…This paper belongs to Topical Collection Z. Latajka Festschrift. and π-bonds for the same pair of subunits [44,[48][49][50][51][52][53][54][55][56][57][58][59][60] remain limited, leaving many questions unanswered.…”