Anion–anion interactions: their nature, energy and role in crystal formation

Abstract

Theoretical and experimental data array confirmTheoretical and experimental data array confirming the possibility of occurrence of bonding interactions in a ing the possibility of occurrence of bonding interactions in a crystal between like-charged species, namely anions, that crystal between like-charged species, namely anions, that contribute significantly to the crystal packing formation is contribute significantly to the crystal packing formation is analyzed. The main types of anion ± anion interactions, analyzed. The main types of anion ± anion interactions, their strength and contribution to the stabilization of ionic their strength and contribution to the stabilization of ionic crystals are systematically analyzed for a wide range of crystals are systematically analyzed for a wide range of organic and inorganic salts. The potential of various theoorganic and inorganic salts. The potential of various theoretical and experimental methods of investigations aimed at retical and experimental methods of investigations aimed at detection of anion ± anion interactions and estimation of detection of anion ± anion interactions and estimation of their energy is discussed. The bibliography includes their energy is discussed. The bibliography includes 142 references 142 references. .

Experimental Charge Density Evidence for Pnicogen Bonding in a Crystal of Ammonium Chloride

“…Based on the separation between neighboring chloride anions in NH 4 Cl (3.8314(1) ), Cl À ···Cl À bonding interactions also may be expected [40] (Figure 2) similar to those found in NaCl [41] or hydroxylammonium chloride NH 3 OHCl. [42] Therefore, the full set of interionic contacts here should include NÀH···Cl hydrogen bonds, Cl···NÀH pnicogen bonds, and Cl···Cl interactions; the latter cannot be described by the s-hole concept because they form no covalent bonds and thus have no s-holes, but they resemble its "like attracting like" cases.…”

Stabilizing hydrogen-hydrogen interactions in cationic indopolycarbocyanine dyes

“…Bader criticized this idea. A detailed explanation and evidence that the presence of BCP of the (3, -1) type corresponds to the binding interaction can be found in Bader's works [15,16] and also in a number of recent reviews [17,18].…”

“…The uniqueness of the QTAIM method is the possibility of determining even very weak interatomic interactions, such as Н---Н, СН---О, as well as cation-cation and anion-anion interactions in crystals [17], which seems at first sight to contradict to classical representations, but however, is confirmed by the data of precise X-ray diffraction studies. Yet another significant advantage of the QTAIM method is the possibility of a quantitative description of interactions between valenceunbound atoms.…”

Structure and spectral properties of truxene dye S5

“…(1) is valid for condition (iii) ( > 0, h e (r) > 0) and, partially, for condition (ii) ( > 0, h e (r) < 0) [17].…”