The influence of pressure on the infrared spectra of hydrogen-bonded solids. III. Compounds with N-H...X bonds

1976 ◽  
Vol 29 (8) ◽  
pp. 1641 ◽  
Author(s):  
SD Hamann ◽  
M Linton
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Infrared Measurements ◽  
Hydrogen Bonded

Infrared measurements have been made of the influence of pressures between 0 and 40 kbar on the stretching and bending frequencies of N-H groups in a range of crystalline compounds which have N-H. . .N, N-H. . .O, N-H. . .S or N-H. . .Cl hydrogen bonds. The frequencies have been found to change in accordance with rules that were derived and tested in Parts I and I1 for other kinds of hydrogen-bond systems.

The influence of pressure on the infrared spectra of hydrogen-bonded solids. VI. Ammonium salts

1978 ◽  
Vol 31 (1) ◽  
pp. 11 ◽  
Author(s):  
SD Hamann
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Spectra ◽  
Ammonium Salts ◽  
Bond Strengths ◽  
As If ◽  
Lower Frequencies ◽  
Hydrogen Bonded

The infrared spectra of 33 polycrystalline ammonium salts have been measured at 25°C, at pressures up to 45 kbar. The N-H stretching and bending bands of the hydrogen-bonded NH4+ ions of most of the salts shift anomalously to higher and to lower frequencies, respectively, as the pressure is raised. In this sense, the salts behave as if they had very strong hydrogen bonds, instead of quite weak ones. ��� A fairly good correlation exists between the N-H stretching frequencies of salts with N+-H...O bonds and their hydrogen bond strengths as measured by the minimum N+...O distances in their crystals.

scholarly journals Di-μ-chlorido-bis[(2,2′-bipyridine-5,5′-dicarboxylic acid-κ2N,N′)chloridocopper(II)] dimethylformamide tetrasolvate

2013 ◽  
Vol 69 (2) ◽  
pp. m73-m74 ◽  
Author(s):  
Sigurd Øien ◽  
David Stephen Wragg ◽  
Karl Petter Lillerud ◽  
Mats Tilset
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Cooh Group ◽  
Stacking Interactions ◽  
Coordination Geometry ◽  
Complex Molecules ◽  
Centroid Distance ◽  
Solvent Molecules ◽  
Hydrogen Bonded

In the title compound, [Cu2Cl4(C12H8N2O4)2]·4C3H7NO, which contains a chloride-bridged centrosymmetric CuIIdimer, the CuIIatom is in a distorted square-pyramidal 4 + 1 coordination geometry defined by the N atoms of the chelating 2,2′-bipyridine ligand, a terminal chloride and two bridging chloride ligands. Of the two independent dimethylformamide molecules, one is hydrogen bonded to a single –COOH group, while one links two adjacent –COOH groupsviaa strong accepted O—H...O and a weak donated C(O)—H...O hydrogen bond. Two of these last molecules and the two –COOH groups form a centrosymmetric hydrogen-bonded ring in which the CH=O and the –COOH groups by disorder adopt two alternate orientations in a 0.44:0.56 ratio. These hydrogen bonds link the CuIIcomplex molecules and the dimethylformamide solvent molecules into infinite chains along [-111]. Slipped π–π stacking interactions between two centrosymmetric pyridine rings (centroid–centroid distance = 3.63 Å) contribute to the coherence of the structure along [0-11].

On the Hydrogen Bond Breaking Ability of Fluorocarbons Containing Higher Halogens

1974 ◽  
Vol 52 (21) ◽  
pp. 3612-3622 ◽  
Author(s):  
Thérèse Di Paolo ◽  
C. Sandorfy
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Bond Breaking ◽  
Anesthetic Activity ◽  
Competitive Mechanism ◽  
Infrared Measurements ◽  
Donor Acceptor

Infrared measurements show that fluorocarbons containing higher halogens are able to open O—H---O, N—H---N, S—H---S, N—H---O=C, type hydrogen bonds. This is probably due to a competitive mechanism of association consisting in the formation of donor–acceptor complexes. It is suggested that the breaking or perturbation of hydrogen bonds by this mechanism is of importance for the explanation of the anesthetic activity of these compounds.

Two polymorphs and the diethylammonium salt of the barbiturate eldoral

2012 ◽  
Vol 68 (2) ◽  
pp. o65-o70 ◽  
Author(s):  
Thomas Gelbrich ◽  
Denise Rossi ◽  
Ulrich J. Griesser
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Barbituric Acid ◽  
Layer Structure ◽  
Chain Structure ◽  
Hydrogen Bond Acceptor ◽  
Layer Structures ◽  
A Chain ◽  
Derivatives Of ◽  
Hydrogen Bonded

Polymorph (Ia) of eldoral [5-ethyl-5-(piperidin-1-yl)barbituric acid or 5-ethyl-5-(piperidin-1-yl)-1,3-diazinane-2,4,6-trione], C11H17N3O3, displays a hydrogen-bonded layer structure parallel to (100). The piperidine N atom and the barbiturate carbonyl group in the 2-position are utilized in N—H...N and N—H...O=C hydrogen bonds, respectively. The structure of polymorph (Ib) contains pseudosymmetry elements. The two independent molecules of (Ib) are connectedviaN—H...O=C(4/6-position) and N—H...N(piperidine) hydrogen bonds to give a chain structure in the [100] direction. The hydrogen-bonded layers, parallel to (010), formed in the salt diethylammonium 5-ethyl-5-(piperidin-1-yl)barbiturate [or diethylammonium 5-ethyl-2,4,6-trioxo-5-(piperidin-1-yl)-1,3-diazinan-1-ide], C4H12N+·C11H16N3O3−, (II), closely resemble the corresponding hydrogen-bonded structure in polymorph (Ia). Like many other 5,5-disubstituted derivatives of barbituric acid, polymorphs (Ia) and (Ib) contain theR22(8) N—H...O=C hydrogen-bond motif. However, the overall hydrogen-bonded chain and layer structures of (Ia) and (Ib) are unique because of the involvement of the hydrogen-bond acceptor function in the piperidine group.

Two methyl 3-(1H-pyrazol-4-yl)octahydropyrrolo[3,4-c]pyrrole-1-carboxylates form different hydrogen-bonded sheets

2013 ◽  
Vol 69 (8) ◽  
pp. 915-919
Author(s):  
Jairo Quiroga ◽  
Jaime Gálvez ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Hydrogen Bonded

In the molecules of both methyl (1RS,3SR,3aRS,6aSR)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxo-5-phenyloctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C25H24N4O4, (I), and methyl (1RS,3SR,3aRS,6aSR)-5-(4-chlorophenyl)-1-methyl-3-(3-methyl-1-phenyl-1H-pyrazol-4-yl)-4,6-dioxooctahydropyrrolo[3,4-c]pyrrole-1-carboxylate, C25H23ClN4O4, (II), the two rings of the pyrrolopyrrole fragment are both nonplanar, with conformations close to half-chair forms. The overall conformations of the molecules of (I) and (II) are very similar, apart from the orientation of the ester function. The molecules of (I) are linked into sheets by a combination of an N—H...π(pyrrole) hydrogen bond and three independent C—H...O hydrogen bonds. The molecules of (II) are also linked into sheets, which are generated by a combination of an N—H...N hydrogen bond and two independent C—H...O hydrogen bonds, weakly augmented by a C—H...π(arene) hydrogen bond.

The influence of pressure on the infrared spectra of hydrogen bonded solids. II. Bihalide salts

1976 ◽  
Vol 29 (3) ◽  
pp. 479 ◽  
Author(s):  
SD Hamann ◽  
M Linton
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Hydrogen Bonds ◽  
High Pressure Phase Transition ◽  
Infrared Measurements ◽  
Normal Hydrogen ◽  
Combination Bands ◽  
Pressure Phase ◽  
Made In ◽  
Hydrogen Bonded

Infrared measurements have been made of the influence of pressures between 0 and 40 kbar on the asymmetrical stretching frequencies v3 and bending frequencies v2 of the hydrogen-bonded ions FHF- and ClHCl- in the solid salts NaHF2, KHF2, NH4HF2, (CH3)4NHCl2 and (C2H5)4NHCl2 at 25�C. The behaviour of the symmetrical stretching frequency v1 for FHF- in KHF2 has been deduced indirectly from the shifts of combination bands. Contrary to the behaviour of compounds with weaker, 'normal', hydrogen bonds, the v3 bands shift to higher frequencies and the v2 bands shift to lower frequencies with increasing pressure. The vl band of KHF2 shifts to higher frequencies. These trends are all in agreement with predictions made in Part I for a simple model of hydrogen bonds. A new high-pressure phase transition has been found to occur in NaHF2 at about 40 kbar.

scholarly journals (2E)-3-(6-Methoxynaphthalen-2-yl)-1-(pyridin-3-yl)prop-2-en-1-one and its cyclocondensation product with guanidine, (4RS)-2-amino-4-(6-methoxynaphthalen-2-yl)-6-(pyridin-3-yl)-3,4-dihydropyrimidine monohydrate: two types of hydrogen-bonded sheet

2014 ◽  
Vol 70 (11) ◽  
pp. 1011-1016 ◽  
Author(s):  
Prakash S. Nayak ◽  
Badiadka Narayana ◽  
Hemmige S. Yathirajan ◽  
Eric C. Hosten ◽  
Richard Betz ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Dihedral Angles ◽  
Form Complex ◽  
Molecular Components ◽  
Hydrogen Bonded

The structures of a chalcone and of its cyclocondensation product with guanidine are reported. In (2E)-3-(6-methoxynaphthalen-2-yl)-1-(pyridin-3-yl)prop-2-en-1-one, C19H15NO2, (I), the planes of the pyridine and naphthalene units make dihedral angles with that of the central spacer unit of 23.61 (13) and 23.57 (15)°, respectively, and a dihedral angle of 47.24 (9)° with each other. The molecules of (I) are linked into sheets by a combination of C—H...O and C—H...π(arene) hydrogen bonds. In the cyclocondensation product (4RS)-2-amino-4-(6-methoxynaphthalen-2-yl)-6-(pyridin-3-yl)-3,4-dihydropyrimidine monohydrate, C20H18N4O·H2O, (II), the dihydropyrimidine ring adopts a conformation best described as a shallow boat. The molecular components are linked by two N—H...O hydrogen bonds, two O—H...N hydrogen bonds and one N—H...N hydrogen bond to form complex sheets, with the methoxynaphthalene interdigitated between inversion-related pairs of sheets.

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].

2-Amino-6-methoxy-4-(4-methylanilino)-5-nitrosopyrimidine and ethylN-[4-(adamantan-1-ylamino)-2-amino-5-nitrosopyrimidin-6-yl]-3-aminopropionate: polarized electronic structures and hydrogen-bonded supramolecular assembly in one and two dimensions

2012 ◽  
Vol 68 (5) ◽  
pp. o199-o203 ◽  
Author(s):  
Andrés F. Yépes ◽  
Alirio Palma ◽  
Antonio Marchal ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Electronic Structures ◽  
Supramolecular Assembly ◽  
Two Dimensions ◽  
A Chain ◽  
Hydrogen Bonded

In both 2-amino-6-methoxy-4-(4-methylanilino)-5-nitrosopyrimidine, C12H13N5O2, (I), and ethylN-[4-(1-adamantylamino)-2-amino-5-nitrosopyrimidin-6-yl]-3-aminopropionate, C19H28N6O3, (II), the nitrosopyrimidine unit is planar and the bond distances provide evidence for significant polarization of the electronic structures. In (II), the ethoxycarbonyl fragment of the molecule is disordered over two sets of sites with occupancies of 0.910 (4) and 0.090 (4). In the molecules of both compounds, there is an intramolecular N—H...O hydrogen bond. The molecules of (I) are linked into a chain of rings by a combination of N—H...O and C—H...O hydrogen bonds, while the molecules of (II) are linked by a two-centre N—H...N hydrogen bond and a three-centre N—H...(N,O) hydrogen bond to form sheets containing four distinct types of ring.

Water bridges anchored by a C–H⋯O hydrogen bond: the role of weak interactions in molecular solvation

2016 ◽  
Vol 18 (40) ◽  
pp. 27745-27749 ◽  
Author(s):  
Aditi Bhattacherjee ◽  
Sanjay Wategaonkar
Keyword(s):  
Hydrogen Bond ◽  
Ab Initio ◽  
Infrared Spectra ◽  
Direct Evidence ◽  
Weak Interactions ◽  
Imidazole Ring ◽  
Water Bridges ◽  
Hydrogen Bonded

Hydrogen-bonded water bridges are re-directed from a polar NH bond to a weakly activated C(2)–H bond upon N-methylation. Infrared spectra, supported by ab initio calculations, provide direct evidence of the role of the C(2)–H donor in the solvation of the imidazole ring.

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