Infrared Studies of the Dynamic Aspects of Hydrogen-Bonding in Hydroxylated Metabolites of 2,5,2′,5′,-Tetrachlorobiphenyl

1976 ◽  
Vol 59 (5) ◽  
pp. 993-1002
Author(s):  
Jo-Yun T Chen
Keyword(s):  
Hydrogen Bonding ◽  
Dynamic Equilibrium ◽  
Spectral Studies ◽  
Ortho Position ◽  
Oh Groups ◽  
Rotational Isomers ◽  
Hydroxylated Metabolites ◽  
Infrared Studies ◽  
Infrared Spectral ◽  
Cis And Trans

Abstract Infrared spectral studies indicate that the hydroxylated 2,5,2′,5′-tetrachlorobiphenyls (TCBs) exist in a dynamic equilibrium of free, intramolecular, and intermolecular hydrogen-bonded forms. The relative abundances of the various species depend upon the polarity of the solvents as well as the physical state of the compound resulting from different configurations, i.e., the monohydroxylated 2,5,2′,5′-TCBs exist as cis and trans rotational isomers of OH with respect to the chlorine atom in the ortho position, and 3,4-dihydro-3,4-dihydroxy-2,5,2′,5′-TCB exists as 2 trans conformers with the OH groups either axial-axial or equatorial-equatorial with respect to the plane of the attached ring. In the solid state, the dimer or polymer is preferred with intermolecular hydrogen-bonding occurring between OH groups.

Infrared Studies of Ethylene Chlorohydrin

1968 ◽  
Vol 51 (4) ◽  
pp. 878-882
Author(s):  
Jo-Yun T Chen ◽  
John H Gould
Keyword(s):  
Solid State ◽  
Vapor Phase ◽  
Infrared Spectra ◽  
Dynamic Equilibrium ◽  
Pure Liquid ◽  
Dilute Solution ◽  
Ethylene Chlorohydrin ◽  
Rotational Isomers ◽  
Infrared Studies ◽  
Infrared Spectral

Abstract The infrared spectra of ethylene chlorohydrin as a pure liquid, as a vapor, in CS2 solution, and as a solid under pressure were obtained. The infrared spectral data obtained indicate that ethylene chlorohydrin consists of a dynamic equilibrium of two rotational isomers which are capable of interconversion by heat or pressure. In the vapor phase and dilute solution the substance consists of the gauche and trans monomers which are interchangeable by heating or cooling. In the pure liquid or in the solid state under pressure, it exists as a gauche dimer and trans tetramer. These two forms are also interchangeable by the application of either pressure or heat.

scholarly journals OH Group Effect in the Stator of β-Diketones Arylhydrazone Rotary Switches

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 374-389 ◽  
Author(s):  
Silvia Hristova ◽  
Fadhil S. Kamounah ◽  
Aurelien Crochet ◽  
Nikolay Vassilev ◽  
Katharina M. Fromm ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Theoretical Calculation ◽  
Molecular Spectroscopy ◽  
Ortho Position ◽  
Intermolecular Hydrogen Bonding ◽  
Group Effect ◽  
Oh Groups ◽  
X Ray ◽  
E And Z Isomers

The properties of several hydrazon-diketone rotary switches with OH groups in the stators (2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-dione, 2-(2-(2-hydroxyphenyl)hydrazono)-1-phenylbutane-1,3-dione and 2-(2-(4-hydroxyphenyl)hydrazono)-1-phenylbutane-1,3-dione) were investigated by molecular spectroscopy (UV-Vis and NMR), DFT calculations (M06-2X/TZVP) and X-ray analysis. The results show that, when the OH group is in ortho position, the E’ and Z’ isomers are preferred in DMSO as a result of a stabilizing intermolecular hydrogen bonding with the solvent. The availability, in addition, of a nitro group in para position increases the possibility of deprotonation of the OH group in the absence of water. All studied compounds showed a tendency towards formation of associates. The structure of the aggregates was revealed by theoretical calculation and confirmed by X-ray analysis.

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.

Cyclic organophosphorus compounds. I. Synthesis and infrared spectral studies of cyclic hydrogen phosphites and thiophosphites

1967 ◽  
Vol 45 (21) ◽  
pp. 2501-2512 ◽  
Author(s):  
A. Zwierzak
Keyword(s):  
Hydrogen Bonding ◽  
Organophosphorus Compounds ◽  
Spectral Studies ◽  
Effect Of Solvent ◽  
Dipole Interactions ◽  
Synthetic Procedure ◽  
Infrared Spectral

A general synthetic procedure leading to cyclic hydrogen phosphites has been devised. The effect of solvent on the P==O and P—H infrared stretching modes of cyclic hydrogen phosphites and thiophosphites has been studied. It is concluded that association of cyclic hydrogen phosphites is attributable to dipole–dipole interactions rather than to hydrogen bonding.

Infrared Studies of Dicyclohexylamine

1972 ◽  
Vol 55 (5) ◽  
pp. 1015-1023
Author(s):  
Jo-Yun T Chen
Keyword(s):  
Crystalline State ◽  
High Pressures ◽  
Dynamic Equilibrium ◽  
Chemical Properties ◽  
Pure Liquid ◽  
Physical And Chemical Properties ◽  
Rotational Isomers ◽  
Infrared Studies ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Some physical and chemical properties of dicyclohexylamine were investigated by IR spectroscopy. The spectra of dicyclohexylamine are presented, not only of the pure liquid, but also of the solid which results from high pressures and low temperatures. The IR spectral data indicate that dicyclohexylamine exists under standard conditions as 3 rotational isomers in dynamic equilibrium. Below – 24°C, dicyclohexylamine in the crystalline state exists entirely in the axial-equatorial form. This work reveals that solid dicyclohexylamine goes through several phase transitions, depending on the temperature and/or pressure. Dicyclohexylamine has marked chemical activities, i.e., the amine group will add to double bonds such as with CS2 and CO2 and forms salts with HC1, acetic acid, and moist NaCl powder. The IR spectra of these derivatives are also presented.

Bis(η5-cyclopentacüenyl)N,N-Disiibstituted Dithiocarbamato(chloro)oxomolybdeniim(VI) Complexes

1980 ◽  
Vol 35 (10) ◽  
pp. 1254-1256 ◽  
Author(s):  
H. S. Sangari ◽  
G. S. Sodhi ◽  
N. K. Kaushik ◽  
R. P. Singh
Keyword(s):  
Magnetic Susceptibility ◽  
Coordination Number ◽  
Electronic Spectra ◽  
Spectral Studies ◽  
Nmr Studies ◽  
Infrared Studies ◽  
Infrared Spectral ◽  
Type C

AbstractBis(η5-cyclopentadienyl)N,N-disubstituted dithiocarbamato(chloro)oxomolybdenum(VI) complexes of the type (C5H5)2MoO(S2CNR2)Cl and (C5H5)2MoO(S2CNRR′)Cl where R = Me, Et, i-Pr and R′ = cyclohexyl (cyhx) have been prepared by the reaction of stoichio­metric amounts of bis(η5-cyclopentadienyl)oxomolybderium(VI) dichloride with sodium dithiocarbamates in refluxing dichloromethane. Infrared spectral studies demonstrate that in these complexes, the dithiocarbamate ligands are bidentate. Hence a coordination number of 7 may be assigned to the molybdenum(VI) atom in each case. In addition to infrared studies, electronic spectra, NMR studies, magnetic susceptibility, elemental an­alyses and conductance measurements have been carried out for these complexes.

Infrared Studies of Water in Crystalline Hydrates: Location of Hydrogen Atoms and Evidence for a Bifurcated Hydrogen Bond in K2SnCl4•H2O

1974 ◽  
Vol 52 (13) ◽  
pp. 2380-2388 ◽  
Author(s):  
Michael Falk ◽  
Chung-Hsi Huang ◽  
Osvald Knop
Keyword(s):  
Hydrogen Bonding ◽  
Spectral Characteristics ◽  
Supplementary Information ◽  
Water Molecules ◽  
Dynamic Coupling ◽  
Hydrogen Atoms ◽  
Infrared Studies ◽  
Infrared Spectral ◽  
Bifurcated Hydrogen Bond ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline K2SnCl4•H2O at different degrees of deuteration were recorded between 4000 and 300 cm−1 at temperatures between 30 and −160 °C. The spectra are consistent with the crystal structure proposed by Kamenar and Grdenić. The water molecules are all equivalent and asymmetric. They are sufficiently well separated from one another for the dynamic coupling of vibrations to be negligible. Both hydrogens of the water molecule participate in hydrogen bonding; one of the hydrogen bonds is weak and bifurcated. Positional parameters of the hydrogen atoms have been calculated using supplementary information from available n.m.r. studies. Infrared spectral characteristics of water molecules engaged in bifurcated hydrogen bonding are discussed.

Far-Infrared Spectral Studies and Hydrogen Bonding of Quinolines

1973 ◽  
Vol 6 (8) ◽  
pp. 505-511 ◽  
Author(s):  
S. Ghersetti ◽  
S. Giorgianni ◽  
G. Spunta
Keyword(s):  
Hydrogen Bonding ◽  
Far Infrared ◽  
Spectral Studies ◽  
Infrared Spectral

Infrared studies on rotational isomerism. III. 2-Chloro- and 2-bromo-ethanol

1969 ◽  
Vol 47 (6) ◽  
pp. 901-910 ◽  
Author(s):  
Paul Buckley ◽  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
Apparent Discrepancy ◽  
Trans Isomers ◽  
Kcal Mole ◽  
Infrared Studies ◽  
Isotopic Molecule ◽  
Intramolecular Hydrogen ◽  
Unambiguous Assignment

The relative intensities of the C—X stretching bands of the gauche and trans isomers in the vapor were measured as a function of temperature up to 165 °C for 2-chloroethanol, and up to 130 °C for 2-bromoethanol. From these the enthalpy differences between the two isomers were found to be 1.20 and 1.45 ± 0.1 kcal mole−1 respectively for the two halogenated ethanols. Similar measurements on the O—H stretching bands gave values higher than the above by 0.45 kcal mole−1 for both compounds. This apparent discrepancy is interpreted as due to a second gauche isomer, the OH group of which is not engaged in intramolecular hydrogen bonding, and which is less stable than the trans isomer.A study of the isotopic molecule ClCH2—CH2OD has led to unambiguous assignment of the OH bending and torsional frequencies. The spectra of the solid show that 2-chloroethanol can exist in two different crystalline phases: a stable one consisting of gauche molecules only, and a metastable one containing both isomers.

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