Water: new aspect of hydrogen bonding in the solid state

Abstract

All water–water contacts in the crystal structures from the Cambridge Structural Database with d OO ≤ 4.0 Å have been found. These contacts were analysed on the basis of their geometries and interaction energies from CCSD(T)/CBS calculations. The results show 6729 attractive water–water contacts, of which 4717 are classical hydrogen bonds (d OH ≤ 3.0 Å and α ≥ 120°) with most being stronger than −3.3 kcal mol−1. Beyond the region of these hydrogen bonds, there is a large number of attractive interactions (2062). The majority are antiparallel dipolar interactions, where the O—H bonds of two water molecules lying in parallel planes are oriented antiparallel to each other. Developing geometric criteria for these antiparallel dipoles (β1, β2 ≥ 160°, 80 ≤ α ≤ 140° and T HOHO > 40°) yielded 1282 attractive contacts. The interaction energies of these antiparallel oriented water molecules are up to −4.7 kcal mol−1, while most of the contacts have interaction energies in the range −0.9 to −2.1 kcal mol−1. This study suggests that the geometric criteria for defining attractive water–water interactions should be broader than the classical hydrogen-bonding criteria, a change that may reveal undiscovered and unappreciated interactions controlling molecular structure and chemistry.

Atomic-Level Insights into a Unique Semi-Clathrate Hydrate Formed in a Confined Environment of Porous Protein Crystal

“…The observed oxygen–oxygen distances in the semi-clathrate are in the range of 2.44–3.28 Å, which is within hydrogen-bonding range (Table S4). − The observed semi-clathrate is similar to the semi-clathrate of Maxi (Figure a and Table S4). …”

Screening for a Fenpropidin Enantiomer with High Activity and Low Toxicity

“…Bond distances below this value are considered strong hydrogen bonds, while hydrogen bond distances above this value are considered relatively weak. 40 The distance between the R-enantiomer and the GLU169 of Δ 8 → Δ 7 -isomerase to form a hydrogen bond was 2.9 Å, while the distance between the S-enantiomer and GLU169 was 3.7 Å (Table 2). The distance between the R-enantiomer and the THR111 of Δ 14 -reductase to form a hydrogen bond was 2.8 Å, while the distance between the S-enantiomer and GLU169 was 3.2 Å.…”

“…In addition, the length of classical hydrogen bonds is less than or equal to 3 Å, and the distance of 2.74 Å divides hydrogen bonds into two categories. Bond distances below this value are considered strong hydrogen bonds, while hydrogen bond distances above this value are considered relatively weak . The distance between the R -enantiomer and the GLU169 of Δ 8 → Δ 7 -isomerase to form a hydrogen bond was 2.9 Å, while the distance between the S -enantiomer and GLU169 was 3.7 Å (Table ).…”

New Aspects of Alcohol–Alcohol and Alcohol–Water Interactions: Crystallographic and Quantum Chemical Studies of Antiparallel O–H/O–H Interactions

“…The quantum chemical calculations at the CCSD(T)/ CBS level revealed that most water−water classical hydrogen bonds in the crystal structures from the CSD have interactions stronger than −3.3 kcal/mol, while antiparallel water−water interactions can be strong as −4.7 kcal/mol with most interactions in the range from −0.9 to −2.1 kcal/mol. 35 Similar to antiparallel interactions in the water dimer, it has been shown that antiparallel interactions of dipoles of C−H and O−H bonds exist in benzene−water and benzene− benzene dimers. 37,38 The interaction energy for the benzene− water dimer with antiparallel C−H and O−H bonds is −2.5 kcal/mol, 37 while the interaction energy of benzene−benzene dimers at large offsets with antiparallel C−H bonds is −2.0 kcal/mol.…”

“…35,36 It is shown that antiparallel interactions of two water molecules, in addition to classical hydrogen bonds [α ≥ 120°; d OH ≤ 3.0 Å (Figures 1 and 2)], are significant modes of interaction of water molecules in the solid state. 35 Namely, 19.1% of all attractive water−water interactions in the structures from the Cambridge Structural Database (CSD) belong to the group of antiparallel dipolar O−H/O−H interactions (Figure 1), defined by the geometric parameters: β 1 and β 2 ≥ 160°, 80°≤ α ≤ 140°, and T HOHO > 40°. The quantum chemical calculations at the CCSD(T)/ CBS level revealed that most water−water classical hydrogen bonds in the crystal structures from the CSD have interactions stronger than −3.3 kcal/mol, while antiparallel water−water interactions can be strong as −4.7 kcal/mol with most interactions in the range from −0.9 to −2.1 kcal/mol.…”