Hydrogen Bonding Contribution to Lipophilicity Parameters. Hydrogen Acceptor and Hydrogen Acceptor Donor Parameters

2004 ◽  
Vol 69 (12) ◽  
pp. 2147-2173 ◽  
Author(s):  
Marvin Charton ◽  
Barbara I. Charton
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Reasonable Assumption ◽  
Hydrogen Acceptor ◽  
Donor Capacity ◽  
The Difference ◽  
Acceptor Capacity ◽  
Lipophilicity Parameters ◽  
Hydrogen Bond Energies

In our analysis of the composition of lipophilicity parameters by the intermolecular force (IMF) model we have made use of nH, the number of OH and/or NH bonds, as a measure of the hydrogen donor capacity of a substituent; and nn, the number of lone pairs on O and/or N atoms in the substituent, as a measure of the hydrogen acceptor capacity of the substituent. The basis of this method is the reasonable assumption that in 55.6 molar water hydrogen bonding is maximized. The method does not account however for differences in the energy of different types of hydrogen bonds, but further assumes that these differences are to a first approximation negligible. In order to improve the model we have defined a scale of group hydrogen bonding acceptor parameters, ηXHA, and overall hydrogen bond parameters ηXHAD from the water/1-octanol partition coefficients of AkX where Ak is alkyl. These parameters should account for both the extent of hydrogen bonding in water and for the difference in hydrogen bond energies of the various types of hydrogen bonds encountered. Correlations of log P values for Ph(CH2)nX, X1(CH2)X2, and substituted amino acids Xaa with the IMF equation using the ηXHA and ηXHAD parameters demonstrated their use. Correlation of log P values for PhX suggested that for many groups separate sets of ηXHA and ηXHAD values are required when they are bonded to sp2 hybridized carbon rather than sp3 hybridized carbon.

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

scholarly journals Crystal structures of butyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate

2019 ◽  
Vol 75 (6) ◽  
pp. 880-887 ◽  
Author(s):  
Rosita Diana ◽  
Angela Tuzi ◽  
Barbara Panunzi ◽  
Antonio Carella ◽  
Ugo Caruso
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Molecular Structures ◽  
Antitumoral Activity ◽  
Space Group ◽  
One Dimensional ◽  
Axis Direction ◽  
Hydrogen Bonding Pattern ◽  
Butyl Group

The title benzofuran derivatives 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF1), C19H18N2O6, and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF2), C18H16N2O7, recently attracted attention because of their promising antitumoral activity. BF1 crystallizes in the space group P\overline{1}. BF2 in the space group P21/c. The nitrophenyl group is inclined to benzofuran moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the molecular structures of BF1 and BF2 is the intramolecular N—H...Ocarbonyl hydrogen bond. In the crystal of BF1, the molecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of molecules along the b-axis direction are linked by O—H...Omethoxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).

scholarly journals Crystal structure and hydrogen bonding in the water-stabilized proton-transfer salt brucinium 4-aminophenylarsonate tetrahydrate

2016 ◽  
Vol 72 (5) ◽  
pp. 751-755 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Network Structure ◽  
Three Dimensional ◽  
Water Molecules ◽  
Arsanilic Acid ◽  
Dimensional Network

In the structure of the brucinium salt of 4-aminophenylarsonic acid (p-arsanilic acid), systematically 2,3-dimethoxy-10-oxostrychnidinium 4-aminophenylarsonate tetrahydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water molecules of solvation are accommodated between the layers and are linked to them through a primary cation N—H...O(anion) hydrogen bond, as well as through water O—H...O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.

Selective encapsulation and extraction of hydrogenphosphate by a hydrogen bond donor tripodal receptor

CrystEngComm ◽  
2020 ◽  
Vol 22 (37) ◽  
pp. 6152-6160
Author(s):  
Sandeep Kumar Dey ◽  
Archana ◽  
Sybil Pereira ◽  
Sarvesh S. Harmalkar ◽  
Shashank N. Mhaldar ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Hydrogen Bond Donor ◽  
Tripodal Receptor ◽  
Multiple Hydrogen Bonds

Intramolecular N–H⋯OC hydrogen bonding between the inner amide groups dictates the receptor–anion complementarity in a tripodal receptor towards selective encapsulation of hydrogenphosphate in the outer urea cavity by multiple hydrogen bonds.

Supramolecular structures of N 4-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines

2003 ◽  
Vol 59 (2) ◽  
pp. 263-276 ◽  
Author(s):  
Manuel Melguizo ◽  
Antonio Quesada ◽  
John N. Low ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Electronic Structures ◽  
Supramolecular Structure ◽  
Supramolecular Structures ◽  
Stacking Interactions ◽  
Molecular Electronic ◽  
Π Stacking

The molecular and supramolecular structures of eight N 4-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines are discussed, along with one analogue containing no nitroso substituent. The nitroso derivatives all exhibit polarized molecular-electronic structures leading to extensive charge-assisted hydrogen bonding between the molecules. The intermolecular interactions include hard hydrogen bonds of N—H...O and N—H...N types, together with O—H...O and O—H...N types in the monohydrate of 2-amino-6-benzyloxy-4-piperidino-5-nitrosopyrimidine, soft hydrogen bonds of C—H...O, C—H...π(arene) and N—H...π(arene) types and aromatic π...π stacking interactions. The predominant supramolecular structure types take the form of chains and sheets, but no two of the structures determined here exhibit the same combination of hydrogen-bond types.

3-(4-Oxocyclohexyl)propionic acid monohydrate: hydrogen bonding in the hydrate of a ζ-keto acid

2007 ◽  
Vol 63 (3) ◽  
pp. o1173-o1175
Author(s):  
Stephanie M. Witko ◽  
Mark Davison ◽  
Hugh W. Thompson ◽  
Roger A. Lalancette
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Carboxyl Group ◽  
Keto Acid ◽  
Carbonyl Groups ◽  
O 178 ◽  
Network Of Hydrogen Bonds

In the title crystal structure, C9H14O3·H2O, the water molecule accepts a hydrogen bond from the carboxyl group [O...O = 2.6004 (13) Å and O—H...O = 163°], while donating hydrogen bonds to the ketone [O...O = 2.8193 (14) Å and O—H...O = 178 (2)°] and the acid carbonyl groups [O...O = 2.8010 (14) Å and O—H...O = 174 (2)°]. This creates a network of hydrogen bonds confined within a continuous flat ribbon two molecules in width and extending in the [101] direction.

Excess volumes of an alcohol + 1,2-dichloroethane

1981 ◽  
Vol 59 (14) ◽  
pp. 2210-2211 ◽  
Author(s):  
Nettem V. Choudary ◽  
Puligundla R. Naidu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Binary Mixtures ◽  
Excess Volumes ◽  
Hydrogen Bond Interaction ◽  
Bond Interaction ◽  
Break Up ◽  
The Difference

Excess volumes for binary mixtures of 1,2-dichloroethane with n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, and n-octanol have been determined at 303.15 K. VE is positive over the whole range of composition in all the mixtures. However, it is noticed that the positive values of VE of mixtures of 1,2-dichloroethane with n-hexanol, n-heptanol, and n-octanol differ from those for the mixtures of 1,2-dichloroethane with corresponding alkanes. The difference has been explained in terms of the break up of hydrogen bonds, interstitial accommodation of 1,2-dichloroethane in alcohol aggregates, and possible hydrogen bond interaction of the type Cl … H—O between unlike molecules.

N—H...S and N—H...O hydrogen bonds: `pure' and `mixed'R22(8) patterns in the crystal structures of eight 2-thiouracil derivatives

2014 ◽  
Vol 70 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Ernst Egert
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Crystal Structures ◽  
Thiouracil Derivatives ◽  
Bonding Patterns

The preferred hydrogen-bonding patterns in the crystal structures of 5-propyl-2-thiouracil, C7H10N2OS, (I), 5-methoxy-2-thiouracil, C5H6N2O2S, (II), 5-methoxy-2-thiouracil–N,N-dimethylacetamide (1/1), C5H6N2O2S·C4H9NO, (IIa), 5,6-dimethyl-2-thiouracil, C6H8N2OS, (III), 5,6-dimethyl-2-thiouracil–1-methylpyrrolidin-2-one (1/1), C6H8N2OS·C5H9NO, (IIIa), 5,6-dimethyl-2-thiouracil–N,N-dimethylformamide (2/1), 2C6H8N2OS·C3H7NO, (IIIb), 5,6-dimethyl-2-thiouracil–N,N-dimethylacetamide (2/1), 2C6H8N2OS·C4H9NO, (IIIc), and 5,6-dimethyl-2-thiouracil–dimethyl sulfoxide (2/1), 2C6H8N2OS·C2H6OS, (IIId), were analysed. All eight structures containR22(8) patterns. In (II), (IIa), (III) and (IIIa), they are formed by two N—H...S hydrogen bonds, and in (I) by alternating pairs of N—H...S and N—H...O hydrogen bonds. In contrast, the structures of (IIIb), (IIIc) and (IIId) contain `mixed'R22(8) patterns with one N—H...S and one N—H...O hydrogen bond, as well asR22(8) motifs with two N—H...O hydrogen bonds.

scholarly journals Hydrogen bonding in the crystal structure of the molecular salt of pyrazole–pyrazolium picrate

2016 ◽  
Vol 72 (6) ◽  
pp. 861-863 ◽  
Author(s):  
Ping Su ◽  
Xue-gang Song ◽  
Ren-qiang Sun ◽  
Xing-man Xu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Salt ◽  
Asymmetric Unit ◽  
Molecular Salt ◽  
Hydrogen Bonded

The asymmetric unit of the title organic salt [systematic name: 1H-pyrazol-2-ium 2,4,6-trinitrophenolate–1H-pyrazole (1/1)], H(C3H4N2)2+·C6H2N3O7−, consists of one picrate anion and one hydrogen-bonded dimer of a pyrazolium monocation. The H atom involved in the dimer N—H...N hydrogen bond is disordered over both symmetry-unique pyrazole molecules with occupancies of 0.52 (5) and 0.48 (5). In the crystal, the component ions are linked into chains along [100] by two different bifurcated N—H...(O,O) hydrogen bonds. In addition, weak C—H...O hydrogen bonds link inversion-related chains, forming columns along [100].

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