The Interplay between Various σ- and π-Hole Interactions of Trigonal Boron and Trigonal Pyramidal Arsenic Triiodides

Abstract

Boron and arsenic triiodides (BI 3 and AsI 3 , respectively) are similar molecules that differ mainly in their geometries. BI 3 is a planar trigonal molecule with D 3h symmetry, while AsI 3 exhibits a trigonal pyramidal shape with C 3v symmetry. Consequently, the As atom of the AsI 3 molecule has three σ-holes, whereas the B atom of the BI 3 molecule has two symmetrical π-holes. Additionally, there are σ-holes on the iodine atoms in the molecules studied. In the first step, we have studied σ-hole and π-hole interactions in the known monocrystals of BI 3 and AsI 3 . Quantum mechanical calculations have revealed that the crystal packing of BI 3 is dominated by π-hole interactions. In the case of AsI 3 , the overall contribution of dihalogen bonding is comparable to that of pnictogen bonding. Additionally, we have prepared the [Na(THF) 6 ] + [I(AsI 3 ) 6 ] − (AsI 3 ) 2 complex, which can be described as the inverse coordination compound where the iodine anion is the center of the aggregate surrounded by six AsI 3 molecules in the close octahedral environment and adjacent two molecules in remote distances. This complex is, besides expected dihalogen and pnictogen bonds, also stabilized by systematically attractive dispersion interactions.

Nuclear Magnetic Shielding of Monoboranes: Calculation and Assessment of11B NMR Chemical Shifts in Planar BX3and in Tetrahedral [BX4]−Systems

“…3). [38][39][40] V max is defined as the value of the most positive electrostatic potential of an electron density surface. This procedure involves, in its last steps, a solution of a secular problem that consists of the diagonalization of the correlation matrix (see Table 5) As a result, it turns out that three factors comprise 92 % of the cumulative proportion of the total variance (for the factor values in terms of the original descriptors, see Table 6).…”

“…Basically, these variables comprise the constituents of the Ramsey equation with the exception of the Taft constants, charges based on natural population analysis (NPA), and magnitude ( V max ) of the so-called π-hole on the respective boron atom (see Figure ). − V max is defined as the value of the most positive electrostatic potential of an electron density surface. This procedure involves, in its last steps, a solution of a secular problem that consists of the diagonalization of the correlation matrix (see Table ).…”

Reverse Sandwich Structures from Interplay between Lone Pair−π-Hole Atom-Directed C···dz2[M] and Halogen Bond Interactions

“…Although lone pair−π (lp−π) and anion−π interactions have been recognized only rather recently (for reviews see refs − ), for the past few years they have been efficiently utilized in mastering molecular materials, − molecular recognition, drug design, − catalytic process development, − organic catalysis, − and many other fields. Generally, (anion/lp)−π interactions are defined as favorable noncovalent contacts between a negatively charged center or a lone pair of a neutral center and electron-deficient π systems. ,, (Anion/lp)−π interactions can be atom-directed, , bond-directed (for instance, with a double bond in the electron-deficient arene ring , ), or cycle-directed: e.g., with arenes and heterocycles (Figure ).…”

“…Generally, (anion/lp)−π interactions are defined as favorable noncovalent contacts between a negatively charged center or a lone pair of a neutral center and electron-deficient π systems. 15,22,23 (Anion/lp)−π interactions can be atom-directed, 13,24 bond-directed (for instance, with a double bond in the electron-deficient arene ring 25,26 ), or cycle-directed: e.g., with arenes 27 and heterocycles 28 (Figure 1).…”

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

“…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.…”