scholarly journals Studies of Hydrogen Bonding BetweenN, N-Dimethylacetamide and Primary Alcohols

2009 ◽  
Vol 6 (s1) ◽  
pp. S143-S146 ◽  
Author(s):  
M. S. Manjunath ◽  
P. Sivagurunathan ◽  
J. Sannappa
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Alkyl Chain ◽  
Hydroxyl Group ◽  
Dielectric Relaxation Time ◽  
Primary Alcohols ◽  
X Band ◽  
Free Hydroxyl ◽  
Stoichiometric Complex

Hydrogen bonding betweenN, N-dimethylacetamide (DMA) and alcohols has been studied in carbon tetrachloride solution by an X-band Microwave bench at 936GHz. The dielectric relaxation time (τ) of the binary system are obtained by both Higasi's method and Gopalakrishna method. The most likely association complex between alcohol and DMA is 1:1 stoichiometric complex through the hydroxyl group of the alcohol and the carbonyl group of amide. The results show that the interaction between alcohols and amides is 1:1 complex through the free hydroxyl group of the alcohol and the carbonyl group of amide and the alkyl chain-length of both the alcohols and amide plays an important role in the determination of the strength of hydrogen bond (O-H: C=O) formed and suggests that the proton donating ability of alcohols is in the order: 1-propanol < 1-butanol < 1-pentanol and the accepting ability of DMA.

MOLECULAR INTERACTION STUDY OF N-BENZYLFORMAMIDE WITH 1-ALCOHOLS USING X-BAND MICROWAVE

2010 ◽  
Vol 24 (02) ◽  
pp. 195-200
Author(s):  
M. S. MANJUNATH ◽  
J. SANNAPPA
Keyword(s):  
Relaxation Time ◽  
Binary Mixture ◽  
Molecular Interaction ◽  
Proton Acceptor ◽  
Single Frequency ◽  
Hydroxyl Group ◽  
Secondary Amide ◽  
Dielectric Relaxation Time ◽  
X Band ◽  
Free Hydroxyl

The secondary amide unit is a subject of particular interest, because of its occurrence in peptides and proteins. Molecular interaction between N-benzylformamide (NBF) with 1-alcohols (1-propanol, 1-butanol, 1-pentanol) has been studied in carbon tetrachloride by using X-band microwave bench at 936 GHz. Dielectric constant (ε') and dielectric loss (ε″) of alcohol and NBF and their binary mixture for different mole fractions of NBF have been determined. Dielectric relaxation time (τ) of the binary system is obtained by both Higasi's method and the Gopalakrishna single-frequency concentration variational method. The results show that the most likely interaction between alcohols and NBF is 1:1 complex for binary mixture through the free hydroxyl group of the alcohol and the carbonyl group of NBF. The alkyl chain-length of both alcohol and amide plays an important role in the determination of the strength of hydrogen bond ( O – H : C = O ) formed. The variation of relaxation time of NBF+1-alcohol mixtures in CCl 4 indicates a weak solute-solvent type of molecular association. The result shows that as the relaxation time of the proton acceptor increases, the donating ability of the solute environment increase.

Physical Stability and Lyophilization of Poly(ε-caprolactone)-b-Poly(ethyleneglycol)-b-Poly(ε-caprolactone) Micelles

2006 ◽  
Vol 6 (9) ◽  
pp. 3032-3039 ◽  
Author(s):  
Yong Hu ◽  
Yin Ding ◽  
Yuan Li ◽  
Xiqun Jiang ◽  
Changzheng Yang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Fluorescence Spectra ◽  
Physical Stability ◽  
Storage Period ◽  
Aqueous Dispersion ◽  
Hydroxyl Group ◽  
Core Shell ◽  
Ft Ir ◽  
The Stability

The stability and lyophilization of core–shell PCL-PEG-PCL micelles were investigated by fluorescence spectra, DLS, DSC, WAXD, and FT-IR. The prepared micelles were not stable when they were stored in aqueous dispersion under different condition. Their size increased in the first 20 days and decreased gradually when the storage period was extended. Lyophilization experiment showed that the cryoprotective agent (glucose) was an essential additive to protect the micelles from aggregating during the lyophilization process. After lyophilizing and re-dispersion, the PCL-PEG-PCL micelles became larger in size compared to as-prepared ones. DSC, WAXD, and IR measurements indicated the hydrogen bonding was formed between the hydroxyl group in glucose and the carbonyl group in PCL-PEG-PCL micelles. The effect of added glucose on protection of micelles from aggregation can be explained by the formation of hydrogen bonding with PCL-PEG-PCL micelles and the formation of solid glucose matrix.

scholarly journals Photoluminescence of self-assembled Ag(i) and Au(i) N-heterocyclic carbene complexes. Interplay the aurophilic, hydrogen bonding and hydrophobic interactions

RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14611-14617 ◽  
Author(s):  
Herbert J. H. Syu ◽  
Josh Y. Z. Chiou ◽  
Ju-Chun Wang ◽  
Ivan J. B. Lin
Keyword(s):  
Hydrogen Bonding ◽  
Liquid Crystal ◽  
Phase Formation ◽  
Alkyl Chain ◽  
Hydrophobic Interactions ◽  
Hydroxyl Group ◽  
Liquid Crystal Phase ◽  
Carbene Complexes ◽  
Hydrogen Bonding Interactions ◽  
Long Alkyl Chain

The incorporation of a 2-hydroxyl group at the long alkyl chain of NHC increases the hydrogen bonding interactions and thus induces the liquid crystal phase formation for the tetra nuclear Ag–NHC complex.

The Dielectic properties of Crystalline Alcohols containing sterically hindered Hydroxyl groups

1953 ◽  
Vol 6 (2) ◽  
pp. 104 ◽  
Author(s):  
RJ Meakins
Keyword(s):  
Hydrogen Bonding ◽  
Hydroxyl Group ◽  
Appreciable Amount ◽  
Hydroxyl Groups ◽  
Dipole Orientation ◽  
Hindered Rotation ◽  
Dielectric Absorption ◽  
Free Hydroxyl ◽  
Sterically Hindered ◽  
High Dielectric

It has been previously suggested that the high dielectric absorption of certain crystalline forms of long-chain alcohols is associated with hydrogen-bonding of the hydroxyl groups. This theory is supported by the results given in the present paper, which show that with other alcohols, in which the hydroxyl groups are sterically hindered, the loss is almost completely eliminated. The smallest losses are obtained with triphenylcarbinol and cholesterol which both possess hydroxyl groups embedded in a bulky molecular structure. For the former compound, infra-red data from the literature indicate the absence of any appreciable amount of hydrogen-bonding and are thus in agreement with the evidence from dielectric measurements. High frequency absorption observed in these compounds is considered to be associated with dipole orientation resulting from hindered rotation of the free hydroxyl groups. The effects of steric hindrance of the hydroxyl group are also observed in tert.-butanol.

Conformation of the esters of steroid hydroxyl groups by infrared spectroscopy

1969 ◽  
Vol 47 (9) ◽  
pp. 1601-1603 ◽  
Author(s):  
C. R. Narayanan ◽  
M. R. Sarma ◽  
T. K. K. Srinivasan ◽  
M. S. Wadia
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Carbonyl Group ◽  
Hydroxyl Group ◽  
Spectral Studies ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Infrared Spectral

Infrared spectral studies show that the carbonyl group of the esters of steroid hydroxyl groups are stabilized near the adjacent alkyl hydrogen atoms; this energy of stabilization appears to be more than that of hydrogen bonding between the carbonyl and a nearby hydroxyl group.

Phosphonylmethoxyalkyl and phosphonylalkyl derivatives of adenine

1988 ◽  
Vol 53 (11) ◽  
pp. 2753-2777 ◽  
Author(s):  
Ivan Rosenberg ◽  
Antonín Holý ◽  
Milena Masojídková
Keyword(s):  
Sodium Periodate ◽  
Alkyl Chain ◽  
Alkaline Treatment ◽  
Hydroxyl Group ◽  
Dialkyl Phosphite ◽  
Analogous Reaction ◽  
Trialkyl Phosphite ◽  
Free Hydroxyl ◽  
Subsequent Cyclization ◽  
Derivatives Of

Analogues of the antivirals (2S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (Ia) and 9-(2-phosphonylmethoxyethyl)adenine (Ib), modified in the alkyl chain, are described. The phosphonylmethoxyalkyl derivatives were prepared by condensation of sodium alkoxides of hydroxyalkyladenines (or their N-protected derivatives) with dimethyl p-toluenesulfonyloxymethanephosphonate (II) followed by alkaline hydrolysis and reactions with halotrimethylsilane, or by reaction of vicinal dihydroxyalkyl derivatives with chloromethanephosphonyl dichloride (XIV) and subsequent cyclization of the intermediates XV in aqueous alkali. In the second case the pure regioisomers were also obtained from substituted dihydroxy derivatives with one free hydroxyl group. The following compounds were prepared in this way: 3-O-methyl ether IIIc and 3-O-octyl ether IVc, 9-(3-phosphonylmethoxypropyl)- (Vc), 9-(4-phosphonylmethoxybutyl)- (Vf), 9-(5-phosphonylmethoxypentyl)- (Vi), 9-(2-phosphonylmethoxypropyl)- (VIc), 9-(1-phosphonylmethoxy-3-hydroxy-2-propyl)- (XIIc), 9-(2-methoxy-3-phosphonylmethoxypropyl)- (XIIIc), erythro-9-(2-phosphonylmethoxy-3,4-dihydroxybutyl)- (VIIc) and threo-9-(4-phosphonylmethoxy-2,3-dihydroxybutyl)adenine (IXc) and its enantiomer (Xc). 9-(2-Phosphonylmethoxy-3,3-dihydroxypropyl)adenine (VIII) was obtained by oxidation of VIIc with sodium periodate, 9-(2-phosphonylmethoxyethoxymethyl)adenine (XIc) by reaction of II with sodium salt of 9-(2-hydroxyethoxymethyl)adenine (XIa). 9-(1,2-Dihydroxy-2-methyl-3-propyl)adenine 1- and 2-phosphonylmethyl ether (XVIb), 9-(3,4-dihydroxybutyl)adenine 3- and 4-phosphonylmethyl ether (XVIIb) and 9-(2,3-dihydroxybutyl)adenine 2- and 3-phosphonylmethyl ether (XVIIIb) were prepared by reaction with chloromethanephosphonyl dichloride (XIV) followed by alkaline treatment. Analogous reaction was also employed in the preparation of regioisomerically pure 1-phosphonylmethyl ethers of 9-(1,2-dihydroxy-3-butyl)adenine (XXIV), 9-(1,2-dihydroxy-2-methyl-3-propyl)adenine (XVIb) and 9-(1,2-dihydroxy-3-nonyl)adenine (XXV). Alkylation of adenine with diethyl chloromethoxymethanephosphonate (XXVII) followed by hydrolysis afforded 9-(phosphonylmethoxymethyl)adenine (XXVIIIb). 9-(Phosphonylmethyl)adenine (XLI) was obtained by condensation of adenine with compound II. Conversion of 9-(ω-hydroxyalkyl)adenines into the ω-halogenoalkyl derivatives followed by reaction with trialkyl phosphite and cleavage was used in the preparation of 9-(2-phosphonylethyl)adenine (XXXIVa), 9-(4-phosphonylbutyl)adenine (XXXIVb) and 9-(2-phosphonylethoxymethyl)adenine (XXXIX). 9-(2-Phosphonyl-2-hydroxyethyl)adenine (Lc) and 9-(3-phosphonyl-3-hydroxypropyl)adenine (Lb) were synthesized by treatment of ω-(adenin-9-yl)alkanals with dialkyl phosphite and subsequent cleavage with halogenotrimethylsilane; the same procedure converted 9-(2-oxopropyl)adenine (XLVIIIa) into 9-(2-phosphonyl-2-hydroxypropyl)adenine (La).

(RS,RS)-5-[Hydroxy(4-methylphenyl)methyl]furan-2(5H)-one

2007 ◽  
Vol 63 (11) ◽  
pp. o4298-o4298
Author(s):  
Thierry Ollevier ◽  
Jean-Emmanuel Bouchard ◽  
Valerie Desyroy ◽  
Christian Tessier
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dihedral Angle ◽  
Title Compound ◽  
Hydroxyl Group ◽  
Torsion Angles ◽  
Relative Configuration ◽  
Compound C ◽  
Stereogenic Centers

The crystal structure of the racemic title compound, C12H12O3, allowed the determination of the relative configuration at the two stereogenic centers. For the R,R isomer, the O—C—C—O and C—C—C—C torsion angles around the bond between the two methine C atoms are 62.38 (15) and −175.49 (13)°, respectively. The furan and tolyl groups are almost perpendicular, with a dihedral angle of 79.39 (5)°. Strong and linear intermolecular O—H...O hydrogen bonding (H...O = 2.04 Å and O—H...O = 177°) is observed between the hydroxyl group and the C=O oxygen.

Jahn-Teller Effect in Hexahydroxocuprate(II) Complexes

1995 ◽  
Vol 60 (9) ◽  
pp. 1429-1434
Author(s):  
Martin Breza
Keyword(s):  
Hydrogen Bonding ◽  
Quantum Chemical ◽  
Potential Surface ◽  
Hydroxyl Group ◽  
Chemical Calculation ◽  
Teller Distortion ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Extremal Values ◽  
Jahn Teller Distortion

Using semiempirical CNDO-UHF method the adiabatic potential surface of 2[Cu(OH)6]4- complexes is investigated. The values of vibration and vibronic constants for Eg - (a1g + eg) vibronic interaction attain extremal values for the optimal O-H distance. The Jahn-Teller distortion decreases with increasing O-H distance. The discrepancy between experimentally observed elongated bipyramid of [Cu(OH)6]4- in Ba2[Cu(OH)6] and the compressed one obtained by quantum-chemical calculation is explainable by hydrogen bonding of the axial hydroxyl group.

Determination of the Fe3+/$${\varvec{\Sigma}}$$Fe Ratio in Synthetic Lead Silicate Slags Using X-Band CW-EPR

2021 ◽  
Author(s):  
Vincent Cnockaert ◽  
Inge Bellemans ◽  
Tijl Crivits ◽  
Henk Vrielinck ◽  
Bart Blanpain ◽  
...  
Keyword(s):  
Lead Silicate ◽  
X Band
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