Intramolecular pnicogen interactions in phosphorus and arsenic analogues of proton sponges

Abstract

A computational study of the intramolecular pnicogen bond in 1,8-bis-substituted naphthalene derivatives (ZXH and ZX2 with Z = P, As and X = H, F, Cl, and Br), structurally related to proton sponges, has been carried out. The aim of this paper is the study of their structural parameters, interaction energies and electronic properties such as electron density on the intramolecular interaction. The calculated geometrical parameters associated to the P···P interaction are in reasonably good agreement with the crystal structures found in a CSD search, in particular those of the halogen derivatives. Isodesmic reactions where the 1,8-bis-substituted derivatives are compared to monosubstituted derivatives have been calculated, indicating that the 1,8 derivatives are more stable than the monosubstituted ones for those cases with X-Z···Z-X and F-Z···Z-H alignments. Electron densities and Laplacians at the BCP on the pnicogen interactions suggest that they can be classified as pure closed shell interactions with a partial covalent character. Electron density shift maps are consistent with the results for intermolecular pnicogen interactions. Relationships between interatomic distance and electron density at the bond critical points and between interatomic distance and the orbital charge transfer stabilization energies have been found.

H2XP:OH2 Complexes: Hydrogen vs. Pnicogen Bonds

“…The pnicogen bond is a Lewis acid-Lewis base interaction in which the Lewis acid is a group 15 element (N, P, As, or Sb) acting as an electron-pair acceptor. [13][14][15]. Pnicogen bonds were first described theoretically for model complexes [16,17], and subsequent studies confirmed the stabilizing nature of pnicogen interactions [18][19][20].…”

“…For these calculations, the Ahlrichs [41] qzp basis set was placed on 13 C, 15 N, 17 O, and 19 F, and the qz2p basis set on 31 P, 35 Cl, and hydrogen-bonded 1 H atoms. The Dunning cc-pVDZ basis set was placed on all other 1 H atoms.…”

Highly Selective Halide Receptors Based on Chalcogen, Pnicogen, and Tetrel Bonds

“…[68,69] This basis set and functional have been applied previously to similar sorts of systems to good effect. [14,[33][34][35][70][71][72][73][74][75] Relativistic effects are expected to be most significant for atoms below the third row of the periodic table. Minima on each potential energy surface were assured by the absence of any negative frequencies.…”

Angular dependence of hydrogen bond energy in neutral and charged systems containing CH and NH proton donors

“…This level of theory is widely used in the literature http and provides accurate data for systems of this sort [15][16][17][18][19][20][21][22]. Interaction energies were partitioned into separate contributions by Symmetry Adapted Perturbation Theory (SAPT) [23,24] at the Hartree-Fock level with the same aug-cc-pVDZ basis set as implemented in the MOLPRO software [25].…”