Heterocyclic Tautomerism. The Solution and Crystal Structures of 1-(4',6'-Dimethylpyrimidin-2'-yl)-3-methylpyrazol-5-ol

1984 ◽  
Vol 37 (2) ◽  
pp. 459 ◽  
Author(s):  
PJ Steel ◽  
AR Whyte
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Crystal Structures ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond

Both in the solid state and in solution, the title compound is shown to exist as the OH tautomer (3), which is stabilized by a strong intramolecular hydrogen bond. Crystals of the pyrazol-5-ol (3) are monoclinic: P 21/c, a 9.692(5), b 7.371(5), c 15.345(8) �, β 106.07(4)�, Z 4; the structure was refined to R 0.072 and Rw 0.062.

(E)-4-Bromo-2-(2-methoxyphenyliminomethyl)phenol

2007 ◽  
Vol 63 (11) ◽  
pp. o4241-o4241
Author(s):  
Zarife Sibel Gül ◽  
Ferda Erşahin ◽  
Erbil Ağar ◽  
Şamil Işık
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Tautomeric Form ◽  
Aromatic Rings ◽  
Compound C ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond

The molecule of the title compound, C14H12BrNO2, is almost planar and the dihedral angle between the planes of the two aromatic rings is 3.8 (2)°. The molecule exists in the crystal structure in the phenol–imine tautomeric form, with the H atom located on O rather than on N. This H atom is involved in a strong intramolecular hydrogen bond.

scholarly journals 1-Hydroxy-2-methoxy-6-methyl-9,10-anthraquinone fromRennellia ellipticaKorth.

2009 ◽  
Vol 65 (6) ◽  
pp. o1435-o1435 ◽  
Author(s):  
Nor Hadiani Ismail ◽  
Che Puteh Osman ◽  
Rohaya Ahmad ◽  
Khalijah Awang ◽  
Seik Weng Ng
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Hydroxy Group ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Compound C ◽  
Planar Molecules ◽  
Intramolecular Hydrogen

The title compound, C16H12O4, exists as planar molecules in the solid state (r.m.s. deviation of 0.02 Å in one molecule and 0.07 Å in the second independent molecule comprising the asymmetric unit). In each molecule, the 1-hydroxy group forms an intramolecular hydrogen bond to the adjacent carbonyl O atom.

(1′R,3S)-2-Oxo-1-(1′-phenylethyl)piperidine-3-carboxylic acid: a case of a very strong intramolecular hydrogen bond

2004 ◽  
Vol 60 (11) ◽  
pp. o2110-o2112
Author(s):  
Ana-María Lumbreras-García ◽  
Alberto Galindo-Guzmán ◽  
Dino Gnecco ◽  
Joel-Luis Terán ◽  
Sylvain Bernès
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Intramolecular Hydrogen Bond ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond

Aromatic amides. IX. Temperature effects on the N.M.R. spectra of substituted acetanilides

1974 ◽  
Vol 27 (12) ◽  
pp. 2617 ◽  
Author(s):  
ID Rae
Keyword(s):  
Hydrogen Bond ◽  
Chemical Shift ◽  
Benzene Ring ◽  
Intramolecular Hydrogen Bond ◽  
Temperature Effects ◽  
Dimethyl Sulphoxide ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond ◽  
Ortho Substituent

N.m.r. spectra have been measured for several anilides in dimethyl sulphoxide solution for temperatures in the range 40-140�. The change of the N-H chemical shift with temperature depends on the nature of the ortho substituent on the benzene ring, being least when a strong intramolecular hydrogen bond is possible between the amide N-H and the ortho substituent. For 2?-nitroanilides, the 6?- proton becomes increasingly deshielded as the temperature is raised.

1-{[5-Fluoro-2-(trifluoromethyl)phenyl]iminomethyl}-2-naphthol

2007 ◽  
Vol 63 (3) ◽  
pp. o1407-o1408
Author(s):  
Yun-Fa Zheng ◽  
Liang-Gui Wang ◽  
Guo-Bing Yan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Schiff Base ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Stacking Interactions ◽  
Dimensional Chain ◽  
One Dimensional ◽  
Compound C ◽  
Intramolecular Hydrogen

The title compound, C18H11F4NO, a Schiff base, has been structurally characterized. One intramolecular hydrogen bond influences the conformation of the molecule. The crystal structure is extended into a one-dimensional chain along the c axis via π–π stacking interactions.

True symmetry or pseudosymmetry: 5-amino-1-(4-methylphenylsulfonyl)-4-pyrazolin-3-one and a comparison with its 1-phenylsulfonyl analogue

2012 ◽  
Vol 69 (1) ◽  
pp. 90-92 ◽  
Author(s):  
Galal H. Elgemeie ◽  
Shahinaz H. Sayed ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bond ◽  
Title Compound ◽  
Acta Cryst ◽  
Interplanar Angle ◽  
Phenyl Derivative ◽  
Compound C ◽  
Independent Molecules ◽  
Intramolecular Hydrogen

The title compound, C10H11N3O3S, (I), crystallizes as the NH tautomer. The two rings subtend an interplanar angle of 72.54 (4)°. An intramolecular hydrogen bond is formed from the NH2group to a sulfonyl O atom. The molecular packing involves layers of molecules parallel to thebcplane atx≃ 0, 1etc., with two classical linear hydrogen bonds (amino–sulfonyl and pyrazoline–carbonyl N—H...O) and a further interaction (amino–sulfonyl N—H...O) completing a three-centre system with the intramolecular contact. The analogous phenyl derivative, (II) [Elgemeie, Hanfy, Hopf & Jones (1998).Acta Cryst.C54, 136–138], crystallizes with essentially the same unit cell and packing pattern, but with two independent molecules that differ significantly in the orientation of the phenyl groups. The space group isP21/cfor (I) butP21for (II), which is thus a pseudosymmetric counterpart of (I).

Temperature dependence of chemical shifts of protons in hydrogen bonds. Experimental evidence on an intramolecular hydrogen bond

1968 ◽  
Vol 46 (17) ◽  
pp. 2865-2868 ◽  
Author(s):  
T. Schaefer ◽  
G. Kotowycz
Keyword(s):  
Hydrogen Bond ◽  
Carbon Tetrachloride ◽  
Chemical Shift ◽  
Hydrogen Bonds ◽  
Temperature Dependence ◽  
Intramolecular Hydrogen Bond ◽  
Chemical Shifts ◽  
Hydroxyl Proton ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond

A temperature dependence of the chemical shift of the hydroxyl proton in the strong intramolecular hydrogen bond in 3,5-dichlorosalicylaldehyde is observed in carbon tetrachloride and benzene-d6 solutions. Its magnitude of 0.25 to 0.30 × 10−2 p.p.m. per ° C over a range of 100 °C is in agreement with the model described by Muller and Reiter (1).

An ESIPT fluorophore with a switchable intramolecular hydrogen bond for applications in solid-state fluorochromism and white light generation

2016 ◽  
Vol 4 (10) ◽  
pp. 2011-2016 ◽  
Author(s):  
Ken-ichi Sakai ◽  
Saki Tsuchiya ◽  
Takemitsu Kikuchi ◽  
Tomoyuki Akutagawa
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Intramolecular Hydrogen Bond ◽  
White Light ◽  
Excitation Wavelength ◽  
Acid Base ◽  
White Light Generation ◽  
Fluorescence Color ◽  
Light Generation ◽  
Intramolecular Hydrogen

Acid/base-switched solid-state fluorochromism and excitation-wavelength-dependent fluorescence color tuning have been demonstrated using an ESIPT fluorophore with a switchable intramolecular hydrogen bond.

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