Hexamers: From Covalently Bound Organic Structures to Hydrogen Bonded Water Clusters

Counteranion-Controlled Water Cluster Recognition in a Protonated Octaamino Cryptand

“…The partially encapsulated water oxygen O2w is displaced 1.683 Å from the plane whereas the external water of the tetramer cluster O4w is 3.784 Å away from the plane passing through central axis. The hydrogen-bonding motif of the water tetramer in the cryptand is very different from those observed experimentally or predicted theoretically in the gas phase. , In this tetramer cluster, two water molecules (O1w and O3w) are involved in the formation of four hydrogen bonds and one water molecule (O2w) is involved in the formation of three hydrogen bonds, whereas O4w, which is outside the cryptand cavity, is only involved in the formation of one hydrogen bond. The unique hydrogen-bonding motif of the water tetramer is due to the influence of the surrounding organic moieties and spatial geometry of the binding sites of the cryptand.…”

Counteranion-Controlled Water Cluster Recognition in a Protonated Octaamino Cryptand

“…The partially encapsulated water oxygen O2w is displaced 1.683 Å from the plane whereas the external water of the tetramer cluster O4w is 3.784 Å away from the plane passing through central axis. The hydrogen-bonding motif of the water tetramer in the cryptand is very different from those observed experimentally or predicted theoretically in the gas phase. , In this tetramer cluster, two water molecules (O1w and O3w) are involved in the formation of four hydrogen bonds and one water molecule (O2w) is involved in the formation of three hydrogen bonds, whereas O4w, which is outside the cryptand cavity, is only involved in the formation of one hydrogen bond. The unique hydrogen-bonding motif of the water tetramer is due to the influence of the surrounding organic moieties and spatial geometry of the binding sites of the cryptand.…”

Dissecting Noncovalent Interactions in Carboxyl‐Functionalized Ionic Liquids Exhibiting Double and Single Hydrogens Bonds Between Ions of Like Charge

“…For validation of the predicted enthalpy of vaporization derived from the above described “centerpiece” method, we calculated clusters of the IL up to 12 “ion pairs” ( n =12) at the B3LYP−D3/6‐31G* level of theory considering Grimme's D3‐dispersion correction [51–53] . We could show earlier that such a cluster size is sufficient to reproduce liquid‐phase properties [54–57] . As shown in Figure 3 we firstly calculated the interaction energies of clusters [(c + =c + )(a − ) 2 ] n /2 with n =2, 4, 6, 8, 10, and 12 relative to the energy of an isolated ion pair (c + −a − ), which is supposed to be the present species in the gas phase.…”

“…For calculating all clusters up to n =12 at the same level of theory, we had to use the small 6–31G* basis set. It includes polarization functions and has been shown to be suitable for calculating hydrogen‐bonded clusters [54–57] . Heavily questioned recently, counterpoise (CP) correction has not been applied [58–60] .…”

Characterization of Supramolecular (H2O)18 Water Morphology and Water-Methanol (H2O)15(CH3OH)3 Clusters in a Novel Phosphorus Functionalized Trimeric Amino Acid Host

“…Indeed, such a large supramolecular 2D cyclic structure for water has not been observed before either in liquid water or in other low dimensional ice. Hitherto, pentagons/hexagons have been characterized to be the basic hydrogen bonding subunits in water clusters [(H 2 O) n n = 8, 10, and 12] in supramolecular compounds. ,− The unique structural morphology of water in (H 2 O) 18 is in stark contrast to the ordered pentagonal and hexagonal water morphologies found in a majority of organic/inorganic supramolecular compounds. − This supramolecular association of 2D water molecules in layers of ( l )- 2 is presumably enforced by the shape of trimeric alanine host channels, whose relatively narrow openings inhibit the formation of more stable three-dimensional water clusters. The average O−O distance of 2.858 Å in the supramolecular (H 2 O) 18 morphology of ( l )- 2 is strikingly similar to the O−O distance of 2.85 Å found in liquid water suggesting close structural similarity of (H 2 O) 18 in ( l )- 2 to liquid water structure …”

Counteranion-Controlled Water Cluster Recognition in a Protonated Octaamino Cryptand

“…The partially encapsulated water oxygen O2w is displaced 1.683 Å from the plane whereas the external water of the tetramer cluster O4w is 3.784 Å away from the plane passing through central axis. The hydrogen-bonding motif of the water tetramer in the cryptand is very different from those observed experimentally or predicted theoretically in the gas phase. , In this tetramer cluster, two water molecules (O1w and O3w) are involved in the formation of four hydrogen bonds and one water molecule (O2w) is involved in the formation of three hydrogen bonds, whereas O4w, which is outside the cryptand cavity, is only involved in the formation of one hydrogen bond. The unique hydrogen-bonding motif of the water tetramer is due to the influence of the surrounding organic moieties and spatial geometry of the binding sites of the cryptand.…”

Dissecting Noncovalent Interactions in Carboxyl‐Functionalized Ionic Liquids Exhibiting Double and Single Hydrogens Bonds Between Ions of Like Charge

“…For validation of the predicted enthalpy of vaporization derived from the above described “centerpiece” method, we calculated clusters of the IL up to 12 “ion pairs” ( n =12) at the B3LYP−D3/6‐31G* level of theory considering Grimme's D3‐dispersion correction [51–53] . We could show earlier that such a cluster size is sufficient to reproduce liquid‐phase properties [54–57] . As shown in Figure 3 we firstly calculated the interaction energies of clusters [(c + =c + )(a − ) 2 ] n /2 with n =2, 4, 6, 8, 10, and 12 relative to the energy of an isolated ion pair (c + −a − ), which is supposed to be the present species in the gas phase.…”

“…For calculating all clusters up to n =12 at the same level of theory, we had to use the small 6–31G* basis set. It includes polarization functions and has been shown to be suitable for calculating hydrogen‐bonded clusters [54–57] . Heavily questioned recently, counterpoise (CP) correction has not been applied [58–60] .…”

Characterization of Supramolecular (H2O)18 Water Morphology and Water-Methanol (H2O)15(CH3OH)3 Clusters in a Novel Phosphorus Functionalized Trimeric Amino Acid Host

“…Indeed, such a large supramolecular 2D cyclic structure for water has not been observed before either in liquid water or in other low dimensional ice. Hitherto, pentagons/hexagons have been characterized to be the basic hydrogen bonding subunits in water clusters [(H 2 O) n n = 8, 10, and 12] in supramolecular compounds. ,− The unique structural morphology of water in (H 2 O) 18 is in stark contrast to the ordered pentagonal and hexagonal water morphologies found in a majority of organic/inorganic supramolecular compounds. − This supramolecular association of 2D water molecules in layers of ( l )- 2 is presumably enforced by the shape of trimeric alanine host channels, whose relatively narrow openings inhibit the formation of more stable three-dimensional water clusters. The average O−O distance of 2.858 Å in the supramolecular (H 2 O) 18 morphology of ( l )- 2 is strikingly similar to the O−O distance of 2.85 Å found in liquid water suggesting close structural similarity of (H 2 O) 18 in ( l )- 2 to liquid water structure …”

Counteranion-Controlled Water Cluster Recognition in a Protonated Octaamino Cryptand

“…The partially encapsulated water oxygen O2w is displaced 1.683 Å from the plane whereas the external water of the tetramer cluster O4w is 3.784 Å away from the plane passing through central axis. The hydrogen-bonding motif of the water tetramer in the cryptand is very different from those observed experimentally or predicted theoretically in the gas phase. , In this tetramer cluster, two water molecules (O1w and O3w) are involved in the formation of four hydrogen bonds and one water molecule (O2w) is involved in the formation of three hydrogen bonds, whereas O4w, which is outside the cryptand cavity, is only involved in the formation of one hydrogen bond. The unique hydrogen-bonding motif of the water tetramer is due to the influence of the surrounding organic moieties and spatial geometry of the binding sites of the cryptand.…”

Dissecting Noncovalent Interactions in Carboxyl‐Functionalized Ionic Liquids Exhibiting Double and Single Hydrogens Bonds Between Ions of Like Charge

“…For validation of the predicted enthalpy of vaporization derived from the above described “centerpiece” method, we calculated clusters of the IL up to 12 “ion pairs” ( n =12) at the B3LYP−D3/6‐31G* level of theory considering Grimme's D3‐dispersion correction [51–53] . We could show earlier that such a cluster size is sufficient to reproduce liquid‐phase properties [54–57] . As shown in Figure 3 we firstly calculated the interaction energies of clusters [(c + =c + )(a − ) 2 ] n /2 with n =2, 4, 6, 8, 10, and 12 relative to the energy of an isolated ion pair (c + −a − ), which is supposed to be the present species in the gas phase.…”

“…For calculating all clusters up to n =12 at the same level of theory, we had to use the small 6–31G* basis set. It includes polarization functions and has been shown to be suitable for calculating hydrogen‐bonded clusters [54–57] . Heavily questioned recently, counterpoise (CP) correction has not been applied [58–60] .…”

Characterization of Supramolecular (H2O)18 Water Morphology and Water-Methanol (H2O)15(CH3OH)3 Clusters in a Novel Phosphorus Functionalized Trimeric Amino Acid Host

“…Indeed, such a large supramolecular 2D cyclic structure for water has not been observed before either in liquid water or in other low dimensional ice. Hitherto, pentagons/hexagons have been characterized to be the basic hydrogen bonding subunits in water clusters [(H 2 O) n n = 8, 10, and 12] in supramolecular compounds. ,− The unique structural morphology of water in (H 2 O) 18 is in stark contrast to the ordered pentagonal and hexagonal water morphologies found in a majority of organic/inorganic supramolecular compounds. − This supramolecular association of 2D water molecules in layers of ( l )- 2 is presumably enforced by the shape of trimeric alanine host channels, whose relatively narrow openings inhibit the formation of more stable three-dimensional water clusters. The average O−O distance of 2.858 Å in the supramolecular (H 2 O) 18 morphology of ( l )- 2 is strikingly similar to the O−O distance of 2.85 Å found in liquid water suggesting close structural similarity of (H 2 O) 18 in ( l )- 2 to liquid water structure …”