Effect of functional group conformation on the infrared spectra of some gem difunctional phenylethylene derivatives

1969 ◽  
Vol 47 (17) ◽  
pp. 3147-3152 ◽  
Author(s):  
D. J. Currie ◽  
C. E. Lough ◽  
F. K. McClusky ◽  
H. L. Holmes
Keyword(s):  
Absorption Band ◽  
Functional Groups ◽  
Infrared Spectra ◽  
Functional Group ◽  
Plane Deformation ◽  
Carbonyl Groups ◽  
Deformation Bands ◽  
Or Groups ◽  
Out Of Plane ◽  
Stretching Vibrations

Except for the benzalmalononitriles, two functional group stretching vibrations occur in the infrared (i.r.) spectra of the β,β-difunctional-styrenes with similar functional groups. For geometrically homogeneous compounds with dissimilar functional groups only one absorption band occurs for each functional group. The two bands for similar functional groups have been ascribed to S-cis- and S-trans-conformations of the carbonyl groups with respect to the ethylene and variation in the frequencies of each of these oriented carbonyls to rotation of the functional group or groups out of the plane of the ethylene by steric factors.Frequencies for ethylenic C—H out of plane deformation bands for β-monofunctional styrenes accorded with those already assigned to this vibration. A similar assignment could not be made for the difunctional analogues.

CONTRIBUTION TO THE INFRARED SPECTRA OF FIVE-MEMBERED N- AND N,S-HETEROCYCLIC COMPOUNDS

1964 ◽  
Vol 42 (1) ◽  
pp. 43-49 ◽  
Author(s):  
C. N. R. Rao ◽  
R. Venkataraghavan
Keyword(s):  
Infrared Spectra ◽  
Oxidation Product ◽  
Heterocyclic Compounds ◽  
Plane Deformation ◽  
Deformation Bands ◽  
Hydrogen Atoms ◽  
Benzene Rings ◽  
Out Of Plane ◽  
Heterocyclic Derivatives

Infrared spectra of 5-membered N- and N,S-heterocyclic derivatives such as triazoles, tetrazoles, thiazoles, thiadiazoles, thiatriazoles, and dithiazoles have been examined and empirical assignments have been made. The spectra of the two dithiazolidine derivatives, isoperthiocyanic acid and oxidation product of dithiobiuret, have been studied in detail. Assignments for benzthiazole derivatives are reported. The CH out-of-plane deformation bands of benzene rings fused to five-membered heterocyclic rings have been found to be in the region 760–740 cm−1, characteristic of four adjacent benzenoid hydrogen atoms.

Synthesis, spectral and electrochemical study of coordination molecules Cu4OX6L4: 4-cyanopyridine Cu4OBrnCl(6−n)(4-CNpy)4 complexes

2010 ◽  
Vol 64 (3) ◽  
Author(s):  
Gregor Ondrejovič ◽  
Adela Kotočová ◽  
Marian Koman ◽  
Peter Segľa
Keyword(s):  
Cyclic Voltammetry ◽  
Infrared Spectra ◽  
Electronic Spectra ◽  
Pyridine Ring ◽  
Pyridine Complexes ◽  
Half Wave ◽  
Out Of Plane ◽  
Donor Acceptor ◽  
Back Bonding ◽  
Stretching Vibrations

AbstractNew 4-cyanopyridine halide and mixed-halide Cu4OBrnCl(6−n)(4-CNpy)4 complexes (4-CNpy = 4-cyanopyridine, n = 0–6) were synthesised, characterised, and studied by infrared spectra, electronic spectra, and cyclic voltammetry. Infrared spectra revealed donor-acceptor vibrational couplings of the Cu4O, Cu-Cl, and Cu-N stretching vibrations with the in-plane and out-of-plane pyridine ring vibrations. The infrared spectra, electronic spectra, and half-wave potentials correspond to a weak donor and a strong acceptor behaviour of the 4-cyanopyridine ligands and to π-back bonding, Cu(II)→pyridine rings. The results were compared with the related pyridine and 4-substituted pyridine complexes.

The infrared spectra of theobromine salts

1967 ◽  
Vol 45 (23) ◽  
pp. 2899-2902 ◽  
Author(s):  
Denys Cook ◽  
Zephyr R. Regnier
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Imidazole Ring ◽  
Free Base ◽  
Absorption Bands ◽  
Out Of Plane ◽  
Stretching Vibrations ◽  
Deformation Modes ◽  
Infrared Absorption Bands

From the infrared spectra of theobromine salts it is concluded that the salts are probably arranged in hydrogen-bonded centrosymmetric pairs involving [Formula: see text] interactions. [Formula: see text] anion− hydrogen bonds are formed by protonation of the free nitrogen atom (N9) in the imidazole ring. Infrared absorption bands arising from the former hydrogen bond constantly appear near 3 000 cm−1, whereas those from the latter shift from 2 580 to 3 300 cm−1, depending on the anion. In-plane NH and N+H deformation modes give bands near 1 485 and 1 160 cm−1, respectively. Out-of-plane NH modes have been located, but precise assignments are not possible.The assignments for some other bands which show deuteration shifts are detailed, and the carbonyl stretching vibrations which increase in frequency on protonation of the free base are identified.

Infrared spectra and hydrogen bonding in some methyl α-glycopyranosides

1975 ◽  
Vol 28 (2) ◽  
pp. 335 ◽  
Author(s):  
AJ Michell
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Bending Vibrations ◽  
Ambient Temperatures ◽  
Out Of Plane ◽  
Stretching Vibrations ◽  
Plane Bending

Spectra in the OH stretching and out-of-plane bending regions of four methyl α-glycopyranosides of known crystal structure have been obtained at ambient and sub-ambient temperatures. Partial deuteration has been used to uncouple the stretching vibrations and assist in assignments of the out-of-plane bending vibrations.

On Line Infrared Identification of Gas Chromatography Effluents

1975 ◽  
Vol 29 (1) ◽  
pp. 24-28 ◽  
Author(s):  
B. Katlafsky ◽  
M. W. Dietrich
Keyword(s):  
Gas Chromatography ◽  
Functional Groups ◽  
Infrared Spectra ◽  
Functional Group ◽  
Fold Increase ◽  
Polar Compounds ◽  
Signal Averaging ◽  
On Line ◽  
Averaging Techniques

On-line infrared spectra obtained with the Norcon RS-1 gas chromatographic identifier are of sufficient quality for qualitative identification of functional groups, chemical classes, or chemical entities. Identification limits for chemical entities vary between 20 and 200 µg, polar compounds having higher sensitivities. Functional group identifications can be made with correspondingly smaller samples. A 5-fold increase in sensitivity was demonstrated using signal-averaging techniques.

PROTONATED CARBONYL GROUPS: V. α-PYRIDONE SALTS

1965 ◽  
Vol 43 (4) ◽  
pp. 749-757 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Carbonyl Group ◽  
Infrared Spectra ◽  
Carbonyl Groups ◽  
Bending Vibrations ◽  
Out Of Plane ◽  
Plane Bending ◽  
Strong Acids

Salts of 1-methyl-2-pyridone and 1-methyl-2-quinolone with strong acids have been prepared and their infrared spectra recorded between 4 000 and 650 cm−1. Protonation of the carbonyl group occurs giving rise to OH stretching, in-plane and out-of-plane bending vibrations which absorb in characteristic regions of the spectrum, namely 1 900 – 3 300 cm−1 (depending on the anion), ~ 1 250 cm−1, and ~ 800 cm−1 respectively, with appropriate shifts on deuteration. Other tentative assignments are made.

Pyrrole studies. VIII. The NH stretching frequencies of substituted pyrroles Acetyl and benzoyl substituents

1966 ◽  
Vol 19 (1) ◽  
pp. 107 ◽  
Author(s):  
RW Guy ◽  
RA Jones
Keyword(s):  
Carbon Tetrachloride ◽  
High Resolution ◽  
Frequency Band ◽  
Infrared Spectra ◽  
Plane Deformation ◽  
Acyl Substituent ◽  
Out Of Plane ◽  
Lower Frequency Band ◽  
Hot Band ◽  
Substituted Pyrroles

The infrared spectra of a number of acylpyrroles have been examined in the NH and CO stretching region under high resolution in carbon tetrachloride. Analysis of the data show-s that the effect of each group on the NH stretching frequency is independent of other substituents and additive. Pyrroles having the acyl substituent in the β-position show two concentration-independent bands. The lower frequency band arises from interaction with the out-of-plane deformation of the NH group, producing a hot band.

The infrared spectra of rhenium and osmium oxide tetrachlorides in the gas phase, condensed phase, and in solution

1972 ◽  
Vol 25 (1) ◽  
pp. 27 ◽  
Author(s):  
CG Barraclough ◽  
DJ Kew
Keyword(s):  
Absorption Band ◽  
Gas Phase ◽  
Diethyl Ether ◽  
Infrared Spectra ◽  
Condensed Phase ◽  
Trigonal Bipyramidal ◽  
Stretching Vibrations ◽  
Osmium Oxide ◽  
Phase Spectra

The infrared spectra of ReOCl4 and OsOCl4 have been measured in the gas phase, in the condensed phase, and in a variety of solvents. In the gas phase spectra the absorption band envelopes corresponding to the metal-oxygen stretching vibrations have been observed and the data are discussed in terms of possible square pyramidal or trigonal bipyramidal structures for the molecules. Evidence is presented showing that acetone and diethyl ether molecules will readily coordinate to these oxide tetrachlorides when dissolved in inert solvents. The effect of traces of water on the same solutions is also described and discussed. Both ReOCl4 and OsOCl4 react with the solvent if dissolved in acetone or diethyl ether and the possibility of the formation of the unknown oxide trichlorides is discussed.

PROTONATED CARBONYL GROUPS: III. ANTIPYRINE SALTS

1963 ◽  
Vol 41 (11) ◽  
pp. 2794-2799 ◽  
Author(s):  
Denys Cook
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Bonds ◽  
Carbonyl Group ◽  
Infrared Spectra ◽  
Strong Absorption ◽  
Carbonyl Groups ◽  
Correlation Field ◽  
Bending Mode ◽  
Out Of Plane ◽  
Stretching Vibration

Salts of antipyrine (2,3-dimethyl-1-phenyl-5-pyrazolone) with halogen acids have been prepared and their infrared spectra from 4000 to 650 cm−1 recorded. Stoichiometrically they are normal 1:1 salts. Identification of bands due to vibrations of the protonating hydrogen atom has been aided by replacement with deuterium atoms. It is concluded that protonation occurs at the carbonyl group from the presence of a doublet (due to correlation field splitting) at 1320 and 1220 cm−1, attributed to the in-plane hydrogen-bending mode. The OH stretching vibration gives rise to bands between 2278 and 2720 cm−1 in the different salts. Out-of-plane hydrogen-bending mode absorptions are observed between 840 and 770 cm−1.More complex acids (HAsF6 etc.) give the anomalous 2 base:1 acid salts, characterized by strong absorption below 1400 cm−1, which probably contain strong, possibly symmetrical, hydrogen bonds.

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