THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY SPECTROSCOPIC METHODS: PART IX. THE ULTRAVIOLET ABSORPTION SPECTRUM OF 3-TRIFLUOROMETHYL-2- NITROPHENOL

1966 ◽  
Vol 44 (8) ◽  
pp. 961-968 ◽  
Author(s):  
A. Balasubramanian ◽  
W. F. Forbes ◽  
J. C. Dearden
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Ultraviolet Absorption Spectrum ◽  
Compound I ◽  
Absorption Bands ◽  
Polar Solvents ◽  
Electronic Interactions ◽  
Spectral Changes ◽  
Solvent Molecules ◽  
Intramolecular Hydrogen

The ultraviolet and infrared spectra of 3-trifluoromethyl-2-nitrophenol (I) and of a number of reference compounds have been determined. The transitions which give rise to the observed absorption bands, as well as the effect of steric and electronic interactions on these transitions, are discussed.Remarkable spectral changes are observed for compound I on altering the solvent from cyclohexane to polar solvents such as ether, ethanol, and water. In cyclohexane solution, there is evidence for steric interactions and for relatively weak intramolecular hydrogen bonding. In polar solvents, rupture of the intramolecular hydrogen bond occurs because solvent molecules attach themselves to the functional groups, and particularly to the phenolic OH group. This, in turn, causes the NO2 group to be twisted out of the plane of the benzene ring.

Two terphenyl-based diol hosts and corresponding solvent inclusions with dimethylformamide and acetonitrile

2015 ◽  
Vol 71 (9) ◽  
pp. 768-775
Author(s):  
Hendrik Klien ◽  
Wilhelm Seichter ◽  
Konstantinos Skobridis ◽  
Edwin Weber
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Solvent Molecule ◽  
Intramolecular Hydrogen Bonding ◽  
Host Lattice ◽  
Solvent Free ◽  
Guest Molecules ◽  
Solvent Molecules ◽  
Intramolecular Hydrogen ◽  
Supramolecular Aggregates

Having reference to an elongated structural modification of 2,2′-bis(hydroxydiphenylmethyl)biphenyl, (I), the two 1,1′:4′,1′′-terphenyl-based diol hosts 2,2′′-bis(hydroxydiphenylmethyl)-1,1′:4′,1′′-terphenyl, C44H34O2, (II), and 2,2′′-bis[hydroxybis(4-methylphenyl)methyl]-1,1′:4′,1′′-terphenyl, C48H42O2, (III), have been synthesized and studied with regard to their crystal structures involving different inclusions,i.e.(II) with dimethylformamide (DMF), C44H34O2·C2H6NO, denoted (IIa), (III) with DMF, C48H42O2·C2H6NO, denoted (IIIa), and (III) with acetonitrile, C48H42O2·CH3CN, denoted (IIIb). In the solvent-free crystals of (II) and (III), the hydroxy H atoms are involved in intramolecular O—H...π hydrogen bonding, with the central arene ring of the terphenyl unit acting as an acceptor. The corresponding crystal structures are stabilized by intermolecular C—H...π contacts. Due to the distinctive acceptor character of the included DMF solvent species in the crystal structures of (IIa) and (IIIa), the guest molecule is coordinated to the hostviaO—H...O=C hydrogen bonding. In both crystal structures, infinite strands composed of alternating host and guest molecules represent the basic supramolecular aggregates. Within a given strand, the O atom of the solvent molecule acts as a bifurcated acceptor. Similar to the solvent-free cases, the hydroxy H atoms in inclusion structure (IIIb) are involved in intramolecular hydrogen bonding, and there is thus a lack of host–guest interaction. As a result, the solvent molecules are accommodated as C—H...N hydrogen-bonded inversion-symmetric dimers in the channel-like voids of the host lattice.

Properties of Olean-12-ene-3α,16β,22α,28-tetrol and Some Derivatives

1996 ◽  
Vol 49 (7) ◽  
pp. 775 ◽  
Author(s):  
TW Hambley ◽  
TW Hambley ◽  
KG Lewis ◽  
KG Lewis ◽  
DJ Tucker ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Crystallographic Data ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Ortho Ester ◽  
Polar Solvents ◽  
Space Group ◽  
X Ray ◽  
Intramolecular Hydrogen

Reaction of olean-12-ene-3β,16β,22α,28-tetrol ( chichipegenin ) (1) with methyl orthoformate gives the 16β,22α,28-orthoformate (2). Acetylation of the ortho ester followed by hydrolysis gives the tetrol 3β-monoacetate (5). It is shown that intramolecular hydrogen bonding occurs in the tetrol (1) and the 3β-monoacetate (5) in non-polar solvents. X-Ray crystallographic data on the tetrol and its tetraacetate (4) are reported. The tetrol,C30H50O4, M 474.72, crystallized in the orthorhombic space group P 212121 with a 12.363(6), b 31.888(3), c 6.962(3) Ǻ, V 2745(1) Ǻ3, Dc(Z = 4) 1.149 g cm-3, N = N(unique) 2394, No 1878 [I > 1.5σ(I)], Nvar 500; R 0.038, Rw 0.040. The tetraacetate , C38H58O8, M 642.87, crystallized in the monoclinic space group P 21, with a 10.603(2), b 16.569(1), c 10.814(1) Ǻ, β 98.72(1)°, V 1877.9(4) Ǻ3, Dc(Z = 2) 1.137g cm-3 N 3090, Rmerge 4.67% for N(unique) 2917, No 2663 [I > 2.5σ(I)], Nvar 414; R 0.053, Rw 0.050.

N.M.R. and absorption spectra of nitrotoluidines

1974 ◽  
Vol 27 (4) ◽  
pp. 915 ◽  
Author(s):  
T Yokoyama
Keyword(s):  
Hydrogen Bonding ◽  
Absorption Band ◽  
Nitro Group ◽  
Absorption Spectra ◽  
Long Range ◽  
Chemical Shifts ◽  
Intramolecular Hydrogen Bonding ◽  
Polar Solvents ◽  
Dimethylamino Group ◽  
Intramolecular Hydrogen

N.m.r. chemical shifts of ring protons and absorption spectra of 4-substituted 2-nitroaniline deriva- tives were investigated. It was ascertained that the rotations of dimethylamino and/or 2-nitro groups are influenced by the resonance interaction of the dimethylamino group with 4-substituents and the C1 → C2 absorption band is displaced bathochromically by resonance saturation with 4-substituents. The long-range coupling of NH with H5 in N-methyl-2-nitro-p-toluidine was found to be absent and it is considered that the intramolecular hydrogen bonding of amino hydrogen with the 2-nitro group is ruptured by ROH and polar solvents.

THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY SPECTROSCOPIC METHODS: PART VII. INTRAMOLECULAR HYDROGEN BONDING AND STERIC INTERACTIONS IN o-NITROBENZALDEHYDE AND RELATED COMPOUNDS

1962 ◽  
Vol 40 (10) ◽  
pp. 1891-1898 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Intramolecular Hydrogen Bonding ◽  
Spectroscopic Methods ◽  
Steric Interactions ◽  
Spectral Changes ◽  
Suitable Reference ◽  
Intramolecular Hydrogen ◽  
Related Compounds

Certain unusual features in the infrared spectra of o-nitrobenzaldehyde have been interpreted either in terms of an intramolecular hydrogen bond or in terms of steric interactions. As an extension of these studies we have investigated the ultraviolet, infrared, and n.m.r. spectra of o-nitrobenzaldehyde and of suitable reference compounds and have re-examined the available other evidence. It is concluded that the observed spectral changes can best be explained in terms of steric interactions rather than in terms of intramolecular hydrogen bonding.

Hydrogen bonding in sulfanes

1968 ◽  
Vol 46 (22) ◽  
pp. 3587-3590 ◽  
Author(s):  
E. Muller ◽  
J. B. Hyne
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Resonance Spectrum ◽  
Chemical Shifts ◽  
Intramolecular Hydrogen Bonding ◽  
Supporting Evidence ◽  
Absorption Bands ◽  
Hydrogen Bonding Interactions ◽  
Intramolecular Hydrogen ◽  
Proton Chemical Shifts

The position of the proton signals in the nuclear magnetic resonance spectrum of sulfanes (H2Sx) is dependent on the sulfur chain length, the sulfane concentration, and the temperature. These proton chemical shifts are interpreted in terms of sulfane–sulfane interactions and intramolecular hydrogen bonding in sulfanes. Supporting evidence is provided by the position and appearance of the SH-absorption bands of the sulfanes in the infrared, which also establishes the existence of sulfane–solvent interactions.It is concluded that sulfanes participate in hydrogen bonding interactions and it is suggested that there may be a special type of intramolecular hydrogen bonding operative in H2S3.

On the Influence of Intra - and Inter-Molecular Hydrogen Bonding on the Excited State Lifetime of Indigo Dyes

1977 ◽  
Vol 32 (8) ◽  
pp. 876-878 ◽  
Author(s):  
W. Windhager ◽  
S. Schneider ◽  
F. Dörr
Keyword(s):  
Hydrogen Bonding ◽  
Excited State ◽  
Hydrogen Bonds ◽  
Molecular Hydrogen ◽  
Intramolecular Hydrogen Bonding ◽  
Excited State Lifetime ◽  
Internal Hydrogen ◽  
Solvent Molecules ◽  
Intramolecular Hydrogen ◽  
Indigo Dyes

Abstract It is shown that intramolecular hydrogen bonding can give rise to very fast nonradiative desactivation of the S1 -state of indigo dyes. In those derivatives, which lack the possibility of internal hydrogen bonds, hydrogen bonding to suitable solvent molecules can provide the channel for fast radiationless transitions. As a consequence, drastic effects on the S1 -state lifetime are observed both as a function of solvent and/or temperature.

Intramolecular hydrogen bonding in cycloalkane-1,2-diol monoacetates

1968 ◽  
Vol 46 (15) ◽  
pp. 2567-2575 ◽  
Author(s):  
Robert W. Wright ◽  
R. H. Marchessault
Keyword(s):  
Hydrogen Bonding ◽  
Frequency Band ◽  
High Frequency ◽  
Intramolecular Hydrogen Bonding ◽  
Carbonyl Oxygen ◽  
Hydroxyl Group ◽  
High Frequency Band ◽  
Absorption Bands ◽  
Hydroxyl Absorption ◽  
Intramolecular Hydrogen

Intramolecular hydrogen bonding in cyclopentane- and cyclohexane-1,2-diol monoacetates was studied by high resolution infrared spectroscopy in the 3μ region. Intramolecular hydrogen bonding was exhibited by all compounds and the data are interpreted in terms of preferred conformations, assuming the acetate group to be exclusively in the "planar trans" form.trans-Cyclopentane-1,2-diol monoacetate exhibited two hydroxyl absorption bands. One band was assigned to free hydroxyl stretching and the other to hydrogen bonding with the carbonyl oxygen so that an equilibrium between two ring conformations must be assumed to exist in solution. With cis-cyclopentane-1,2-diol monoacetate only a strong high frequency band was observed, and this was attributed to hydrogen bonding to the alkoxyl oxygen.trans- and cis-cyclohexane-1,2-diol monoacetate both exhibited two hydroxyl absorption bands. With the former, the hydroxyl group was assumed to be exclusively in an equatorial position to permit hydrogen bonding to both the alkoxyl and carbonyl oxygens. Similarly, in the latter, the high frequency band was attributed to hydrogen bonding to the alkoxyl oxygen atom while the low frequency band was assigned to hydrogen bonding to the carbonyl oxygen.

scholarly journals THE STUDY OF HYDROGEN BONDING AND RELATED PHENOMENA BY ULTRAVIOLET LIGHT ABSORPTION: PART VI. THE EFFECT OF STERIC INTERACTIONS ON THE INTRAMOLECULAR HYDROGEN BOND IN o-NITROPHENOL

1960 ◽  
Vol 38 (10) ◽  
pp. 1852-1864 ◽  
Author(s):  
J. C. Dearden ◽  
W. F. Forbes
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bond ◽  
Alkyl Substituent ◽  
Intramolecular Hydrogen Bonding ◽  
Vibration Band ◽  
Absorption Bands ◽  
Steric Interactions ◽  
Stretching Vibration ◽  
Intramolecular Hydrogen

Intramolecular hydrogen bonding occurring in o-nitrophenol is discussed with special reference to the effects of the steric interactions on the absorption bands and on the bonding. An alkyl substituent vicinal to the OH group, or a methyl group vicinal to the NO2 group appears to strengthen the intramolecular hydrogen bond in o-nitrophenol. The O—H vibrational stretching frequency in o-nitrophenol appears to be more susceptible to steric than to mesomeric interactions, and a methyl substituent vicinal to the nitro group in o-nitrophenols is found to give rise to a characteristic O—H stretching vibration band. For 6-t-butyl-2-nitrophenol, a special, "protected" hydrogen bond is postulated. In some of the o-nitrophenols, intermolecular hydrogen bonding gives rise to appreciable ultraviolet intensity decreases presumably because of increased steric interactions.

Hydrogen bonding due to regioisomerism and its effect on the supramolecular architecture of diethyl 2-[(2/4-hydroxyanilino)methylidene]malonates

2012 ◽  
Vol 69 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Andivelu Ilangovan ◽  
Perumal Venkatesan ◽  
Rajendran Ganesh Kumar
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Mirror Plane ◽  
Supramolecular Architecture ◽  
Intermolecular Hydrogen Bonding ◽  
Compound I ◽  
Monoclinic Crystal ◽  
One Dimensional ◽  
Intramolecular Hydrogen ◽  
Compound Ii

Diethyl 2-[(2-hydroxyanilino)methylidene]malonate, (I), and diethyl 2-[(4-hydroxyanilino)methylidene]malonate, (II), both C14H17NO5, crystallize in centrosymmetric orthorhombic and monoclinic crystal systems, respectively. Compound (I) resides on a crystallographic mirror plane and displays bifurcated intramolecular hydrogen bonding, as well as intermolecular hydrogen bonding due to the position of the hydroxy group. Compound (II) has a single intramolecular N—H...O hydrogen bond. Infinite one-dimensional head-to-tail chains formed by O—H...O hydrogen bonding are present in both structures. The molecular packing is mainly influenced by the intermolecular O—H...O interactions. Additionally, C—H...O interactions crosslinking the chains are found in (II).

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