Comparative investigation of manifestations of ion-molecule and intermolecular hydrogen bonds in the absorption bands of stretching vibrations of hydroxyl groups

1979 ◽  
Vol 30 (3) ◽  
pp. 361-364 ◽  
Author(s):  
I. S. Perelygin ◽  
V. Ya. Mel'nichenko ◽  
A. M. Afanas'eva
Keyword(s):  
Hydrogen Bonds ◽  
Comparative Investigation ◽  
Hydroxyl Groups ◽  
Absorption Bands ◽  
Intermolecular Hydrogen Bonds ◽  
Stretching Vibrations

1-(4-Chlorophenyl)-4-(2-furoyl)-3-(2-furyl)-1H-pyrazol-5-ol

2007 ◽  
Vol 63 (3) ◽  
pp. o1289-o1290 ◽  
Author(s):  
Jin-Zhou Li ◽  
Heng-Qiang Zhang ◽  
Hong-Xin Li ◽  
Pi-Zhi Che ◽  
Tian-Chi Wang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Intermolecular Hydrogen Bond ◽  
Hydroxyl Groups ◽  
Intermolecular Hydrogen Bonds ◽  
Compound C ◽  
Graph Set

The crystal structure of the title compound, C18H11ClN2O4, contains intra- and intermolecular hydrogen bonds that link the ketone and hydroxyl groups. The intermolecular hydrogen bond results in the formation of a dimer with an R 2 2(12) graph-set motif.

scholarly journals Deprotonation of resorcinarenes and novel ammonium salt complexes

2014 ◽  
Vol 70 (a1) ◽  
pp. C678-C678
Author(s):  
Ngong Beyeh ◽  
Arto Valkonen ◽  
Fanfang Pan ◽  
Kari Rissanen
Keyword(s):  
Hydrogen Bonds ◽  
Binding Sites ◽  
Molecular Complexes ◽  
Ammonium Salts ◽  
Hydroxyl Groups ◽  
Binding Modes ◽  
Intermolecular Hydrogen Bonds ◽  
Guest Molecules ◽  
Cone Conformation ◽  
Intramolecular Hydrogen

The bowl shape cavity of resorcinarenes usually stabilized by four intramolecular hydrogen bonds offers an interesting array of binding modes such as C–H...π and cation...π interactions to recognize a variety of guests. The multiple hydroxyl groups can participate in a series of intermolecular hydrogen bonds with guest molecules. This unique cone conformation of resorcinarenes has led to the synthesis of many receptors with convergent arrangement of binding sites suitable for molecular recognition in many applications. Unfunctionalized resorcinarenes are known to easily form molecular complexes with guests of varying shapes and sizes. Amines are very common bases used in many catalytic processes. A good example is the use of amines as bases in the alkylation and acylation of resorcinarenes leading to cavitands, carcerands, hemicarcerands and velcrands. The use of amines in such reactions is to deprotonate the resorcinarene hydroxyl groups, hence facilitating the alkylation and acylation processes. The subsequently protonated ammonium cation then forms interesting supramolecular complexes with the anionic and dianionic resorcinarenes. Furthermore, secondary and tertiary ammonium salts possess hydrogen bond donating -NH2 and -NH respectively and these can further enhance their complexation through intermolecular hydrogen bonds. Here we present our recent examples of supramolecular assemblies resulting from the deprotonation of resorcinarenes by mono- and dibasic amines. Also, our latest supramolecular co-crystals between resorcinarenes as the receptors and a series of secondary and tertiary mono- and diammonium cations are illustrated.

scholarly journals IR-spectroscopy of hydrogen bonding in wood: Picea abies.

2017 ◽  
Author(s):  
В.И. Иванов-Омский ◽  
С.М. Герасюта ◽  
Е.И. Иванова
Keyword(s):  
Hydrogen Bonds ◽  
Picea Abies ◽  
Low Frequency ◽  
Temperature Stability ◽  
Experimental Spectrum ◽  
Hydroxyl Groups ◽  
Absorption Bands ◽  
Oh Groups ◽  
Adult Trees ◽  
Before And After

Исследованы ИК-спектры древесины ели обыкновенной в области поглощения валентными колебаниями гидроксильных групп. Изучались как образцы естественной влажности, так и подвергнутые отжигу при 105 °С. Образцы для исследований отбирались из взрослого дерева ели обыкновенной (Picea abies) на высоте 2,5–3 м (возраст в районе спилов 25–30 лет). Из безcучковой зоны вырезались образцы в виде кубиков размером 3×3×3 см3, из которых непосредственно перед записью спектра изготовлялось пять тангенциальных микротомных срезов толщиной 80–100 мкм. Спектральный анализ проводился с помощью ИК-Фурье спектрометра ФСМ-1201 с разрешением 4 см–1. Показано, что реальная микроструктура ели не препятствует разделению рассеянного и поглощаемого излучений. Для характеристики длин и энергий водородных связей использованы известные корреляционные соотношения частот поглощения гидроксильными группами, охваченными водородными связями, с их длиной и энергией. C этой целью экспериментальный спектр в области поглощения ОН-группами аппроксимируется гауссовыми контурами, каждый из которых ассоциируется с определенной разновидностью Н-связи. Сдвиги частот подгоночных контуров относительно частоты ОН-группы, не охваченной Н-связью, использованы для оценки энергий и длин связей, а соотношение их площадей – для оценки их концентраций. Показано, что при термическом отжиге происходит выжигание низкочастотного крыла полосы поглощения ОН-групп. Приводится диаграмма распределения Н-связей по концентрациям до отжига и после. Показано, что при отжиге число наиболее сильных связей незначительно уменьшается, но их энергия уменьшается заметно. Судя по величине частоты эти полосы поглощения относятся к межмолекулярным связям, и уменьшение их энергии означает, что отжиг затрагивает в первую очередь именно эти связи. Самые слабые исчезают совсем. Детальное исследование этого явления позволит обосновать выбор предельных температур тепловой обработки древесины, не нарушающих ее механических свойств. Отмечается более высокая температурная стабильность внутримолекулярных связей с энергией ≈10 кДж/моль. Investigated the IR spectra of spruce wood in the area of absorption of the stretching vibrations of hydroxyl groups. Been studied, as samples with natural moisture, and subjected to annealing at S. Samples for research were collected from adult trees of Norway spruce (Picea abies) at a height of 2.5–3.0 m (age in the area of cut 25–30 years). From cleared areas were cut samples in the form of cubes of size 3×3×3 cm3, of which just before recording the spectrum produced 5 tangential microtome sections with a thickness of 80–100 nm. Spectral analysis was performed using IR-Fourier spectrometer FSM-1201 with a resolution of 4 cm–1. Shows that the real microstructure of spruce does not prevent the separation of scattered and absorbed radiation. For the characteristic lengths and energies of hydrogen bonds used are known from the literature correlation of the ratio between the frequency of absorption of hydroxyl groups covered by hydrogen bonds with their length and energy. To this end, the experimental spectrum in the region of absorption of OH-groups approximated by a Gaussian contours, each of which is associated with a certain kind of H-bonds. The frequency shifts fitting contours of the relative frequency of OH-groups not covered by the H-bond, is used to evaluate energies and bond lengths, and the ratio of their squares to estimate their concentrations. It is shown that under thermal annealing is burning low frequency wing of the absorption bands of OH-groups. A diagram of the distribution of H-bonds energy on concentrations presented before and after annealing. It is shown that annealing the strongest bonds is slightly decreasing, but their energy decreases significantly. The weakest disappear altogether. A detailed study of this phenomenon will allow us to justify the choice of limiting the temperature of the heat treatment of wood that do not violate its mechanical properties. Noteworthy higher temperature stability of intramolecular bonds with energies of ≈10 kJ/mol.

Inhibitors of endo-α-mannosidase. Part II. 1-Deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin and congeners modified in the mannojirimycin unit

1993 ◽  
Vol 71 (11) ◽  
pp. 1928-1942 ◽  
Author(s):  
Ulrike Spohr ◽  
Mimi Bach ◽  
Robert G. Spiro
Keyword(s):  
Hydrogen Bonds ◽  
Conformational Analysis ◽  
Chemical Shifts ◽  
Hydroxyl Groups ◽  
Enzyme Complex ◽  
Chemical Modifications ◽  
Intermolecular Hydrogen Bonds ◽  
Glycoprotein Processing ◽  
Nuclear Overhauser ◽  
Reported Data

The syntheses of 1-deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin (9) and its 2-deoxy, 2-O-methyl, 4-deoxy, 4-O-methyl, 6-deoxy, 6-O-methyl, N-methyl, and N-propyl congeners are described. Since 9 was previously shown to effectively inhibit endo-α-D-mannosidase, a glycoprotein-processing hydrolase, these chemical modifications were designed to assist in the assessment of intermolecular hydrogen bonds of the inhibitor–enzyme complex. The previously reported data require that all hydroxyl groups of the deoxymannojirimycin unit of 9, namely, OH-2, OH-4, OH-6, and also the NH-5 group, interact with charged and polar groupings of the enzyme, since deoxygenations and alkylations abolished or significantly reduced activities. Conformational analysis of 9 and some of its congeners based on NMR chemical shifts, experimental and theoretical nuclear Overhauser enhancements, and HSEA calculations were performed. The chemical modifications of the glucose unit of 9 are described in the accompanying paper.

scholarly journals Hydrogen bonding systems in birch bark

2020 ◽  
pp. 189-198
Author(s):  
Л.Л. Леонтьев ◽  
И.Д. Лобок ◽  
В.И. Иванов-Омский ◽  
А.С. Смолин
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Frequency Shift ◽  
Hydroxyl Group ◽  
Birch Bark ◽  
Hydroxyl Groups ◽  
Absorption Bands ◽  
Hydrogen Bond Energy ◽  
Absorption Region ◽  
Oh Groups

Произведено сравнение систем водородных связей во внешнем и внутреннем слоях березовой бересты, в сравнении с водородными связями в высококачественной бумаге и в образце выделенной из древесины целлюлозы. Интервал исследуемых частот от 3000 до 3700 см-1, ограничен областью поглощения гидроксильными ОН-группами, частоты которых наиболее чувствительны к возникновению Н-связей. Для оценки параметров Н-связей проводилась деконволюция полос поглощения ОН-групп гауссовыми компонентами. Для корректного выделения поглощения гидроксильными группамипервоначально деконволюции подвергается весь фрагмент, включающий в себя полосы поглощения как метиленовым, так и гидроксильными группами. В дальнейшем анализировались только параметры контуров деконволюции, относящейся к гидроксильным группам. Принималось, что каждый компонент деконволюции может быть ассоциирован с определенным типом водородной связи. Определялся сдвиг частот компонентов деконволюции относительно собственной частоты колебаний изолированной гидроксильной группы, не охваченной по этой причине водородной связью. Для определения энергии водородных связей использовались литературные данные по корреляции энергии водородной связи с частотным сдвигом. Относительная плотность водородных связей оценивалась по отношению площадей контуров деконволюции. A comparison was made of the hydrogen bond systems in the outer and inner layer of birch bark, as well as a comparison of high-quality paper with a sample of pure pulp. The range of frequencies under study from 3000 to 3700 cm-1 is limited by the absorption region by hydroxyl OH groups, the frequencies of which are most sensitive to the occurrence of H bonds. To estimate the parameters of H-bonds, the absorption bands of OH groups were deconvolved by Gaussian components. In order to correctly isolate the absorption by hydroxyl groups, the entire fragment, whichincludes absorption bands of both methylene and hydroxyl groups, is initially deconvolved. In the future, only the parameters of the deconvolution contours related to hydroxyl groups were analyzed. It was assumed that each component of deconvolution can be associated with a certain type of hydrogen bond. The frequency shift of the components of the deconvolution was determined relative to the natural frequency of vibrations of the isolated hydroxyl group, which is therefore not covered by a hydrogen bond. To determine the energy of hydrogen bonds, we used literature data on the correlation of the hydrogen bond energy with a frequency shift. The relative density of hydrogen bonds was estimated by the ratio of the area of the contours of deconvolution.

IR spectra of methyltetrosides and their monomethyl ethers in the region of valence vibration of hydroxyl groups

1981 ◽  
Vol 46 (13) ◽  
pp. 3289-3293 ◽  
Author(s):  
Jiří Jarý ◽  
Miroslav Marek
Keyword(s):  
Hydrogen Bonds ◽  
Ir Spectra ◽  
Valence Vibration ◽  
Hydroxyl Groups ◽  
Spectral Absorption ◽  
Absorption Bands ◽  
Intramolecular Hydrogen Bonds ◽  
Individual Bands ◽  
Intramolecular Hydrogen

IR Spectral absorption bands ν(OH) (3 700 to 3 400 cm-1) of the both anomers of methyl D-threofuranoside, methyl-D-erythrofuranoside, and their monomethyl ethers have been studied in dilute tetrachloromethane solution. For these 11 compounds positions and intensities of individual bands are discussed with respect to possible formation of intramolecular hydrogen bonds.

scholarly journals SYLFATION OF XYLAN WITH SULFAMIC ACID IN N,N-DIMETHYLFORMAMIDE

2017 ◽  
pp. 29-36
Author(s):  
Владимир (Vladimir) Александрович (Aleksandrovich) Левданский (Levdanskii) ◽  
Александр (Aleksandr) Александрович (Aleksandrovich) Кондрасенко (Kondrasenko) ◽  
Александр (Aleksandr) Владимирович (Vladimirovich) Левданский (Levdanskii) ◽  
Борис (Boris) Николаевич (Nikolaevich) Кузнецов (Kuznetsov)
Keyword(s):  
13C Nmr ◽  
Sulfamic Acid ◽  
13C Nmr Spectroscopy ◽  
Partial Substitution ◽  
Hydroxyl Groups ◽  
Absorption Bands ◽  
Nmr Spectrum ◽  
Substitution Degree ◽  
Stretching Vibrations ◽  
First Time

Sulfation of birch wood xylan by sulfamic acid in N,N-dimethylformamide (DMF) in the presence of urea was studied for the first time. The effect of the duration of sulfation of xylan with a mixture of sulfamic acid–urea in DMF on the yield and substitution degree of xylan sulfates was studied. The sulfur content in the obtained samples was determined using chemical method. It was found, that the degree of substitution in the obtained xylan sulfates was in the range from 1.30 to 1.64 at sulfation for 1–2 hours. The structure of initial and sulfated xylan was investigated with the use of FTIR and 13C NMR spectroscopy methods. The introduction of sulfate groups into the structure of xylan was confirmed by appearance in FTIR spectra new absorption bands characteristic for the stretching vibrations n (C–O–S) at 804 cm-1, symmetric stretching vibrations ns (SO2) at 1009 cm-1, asymmetric stretching vibrations nas (SO2) at 1244 and 1260 cm-1.Studying of 13C NMR spectrum of the obtained xylan sulfates showed that there was partial substitution of hydroxyl groups at С2 and С3 positions of anhydroxylose units of xylan.

Hydrogen bonding in organic compounds. IX. Intramolecular actions between the primary amine group and amino, nitro, sulphide, and sulphone groups in aromatic compounds

1964 ◽  
Vol 17 (8) ◽  
pp. 860 ◽  
Author(s):  
AN Hambly ◽  
BV O'Grady
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Compounds ◽  
Aromatic Compounds ◽  
Amine Group ◽  
Intermolecular Hydrogen Bonds ◽  
Amino Derivatives ◽  
Stretching Vibrations ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

Spectroscopic evidence for the existence of intermolecular hydrogen bonds between aniline molecules has been obtained. Examples show the existence of intramolecular hydrogen bonds in orthodiamines, some amino-derivatives of heterocycles, 2-nitro-amines, 2-amino-sulphones, and 2-amino-sulphides. Some new observations, which do not agree with Krueger's interpretation of the profile of the overtone bands due to NH2 stretching vibrations, are recorded.

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