Structural Elucidation of NO Clusters at Low Temperatures: Exemplary Framework Stabilized by π-Hole-Driven N···O and N···N Pnicogen Bonding Interactions.

NO is a classic prototype, in which central nitrogen is sufficiently electropositive with a positive potential of 20 kcal mol in magnitude to qualify it as a possible pnicogen. This was applied to a test with NO clusters using calculations in association with various molecular topographic tools. The structure of the energetically dominant and NO dimer was in favor of a perpendicular geometry, where the central nitrogen atom of the NO submolecule assumed a near 90° angle with the adjacent N═O and/or N═N moiety, which provides the affirmation of central nitrogen as a possible π-hole-driven pnicogen.

Unique Dispersion-Induced Tetrel Bond with Co-operative σ-hole-Induced Pnicogen Bond in the POCl-Acetone Heterodimer: Experimental Confirmation at Low Temperatures.

Both tetrel and pnicogen bonds are known to be induced through σ-/π-holes. This work reports computational and experimental evidence of the carbonyl carbon of acetone hosting a tetrel bond by rather electrostatic forces, for the first time, while phosphorus of POCl sustains pnicogen bonding via the σ-hole. Heterodimers of POCl with acetone (CHCOCH) have been isolated within inert gas matrixes of Ar and N at 12 K.

Unique O═N...O Pnicogen Interactions in Nitromethane Dimers: Evidence Using Matrix Isolation Infrared Spectroscopy and Computational Methodology.

Geometries of nitromethane homodimers have been revisited using and density functional methodologies, following their formation within cryogenic matrices, confirmed using infrared spectroscopy. In contrast to the claim that the intermolecular interactions are due to dispersion forces or very weak hydrogen bonds, in the present work, concrete evidence for the prevalence of O═N..