Carbonyl Stretch Research Articles

Effects of Neutral and Anionic Substituents on the Carbonyl Stretching Band of Substituted Benzophenones

Abstract Satisfactory correlations were found of the frequencies of the title band (νCO) with 6+ and other substituent constants. The correlations proved valid for benzophenones with both neutral and anionic substituents (more than 100 compounds). The integrated intensities of the νCO bands (A1/2 CO) did not correlate with any type of substituent constants; the decrease in ACO in the cases of benzophenones with strong electron-releasing substituents was ascribed to a resonance-induced intensity borrowing from νCO BY THE aromatic skeletal bands (8-type). This statement wa confirmed by IR data few deuterated benzophenones.

Optical rotatory dispersion studies—131: Demonstration of a conformational isotope effect in deuterium substituted cyclopentanones

The synthesis and chiroptical properties of three chiral, deuterium-substituted cyclopentanones are reported which shed light on subtle conformational changes. Thus, the CD spectra of (3 R)-3-deuteriocyclopentanone ( 1), (3 S, 4 S)-3,4-dideuteriocyclopentanone ( 2) and (3 S, 4 S)-2,2,3,4,5,5-hexadeuteriocyclopentanone ( 3) are found to undergo an increase (in the absolute sense) of the rotational strength on lowering the temperature. This change is associated with a shift in the conformational equilibrium towards the twist conformation with the deuterium in the quasi-axial position. Using literature estimates for the rotational strength of the involved twist conformation, enthalpy differences of approximately − 1, − 4 and − 6 cal/mol were calculated for the respective conformational equilibria of 1,2 and 3. Empirical force field calculations were found to be in qualitative agreement with the experimental results when weaker non-bonded interactions for deuterium were used. The gas-phase spectra of 1 and 2 are reported which reveal a surprisingly well resolved vibrational fine structure. Two superimposed main progressions with a spacing of 1250 cm −1 extending up to the sixth overtone are identified. It is suggested that they represent progressions in the excited state carbonyl stretch mode built upon two pseudo origins.

ChemInform Abstract: STRUCTURE OF (RH2BR2(μ‐CO)((C6H5)2PCH2P(C6H5)2)2): A BINUCLEAR RHODIUM CARBONYL COMPLEX HAVING AN UNUSUALLY LOW CARBONYL STRETCHING FREQUENCY

Chemischer InformationsdienstVolume 11, Issue 48 Physical Organic Chemistry ChemInform Abstract: STRUCTURE OF (RH2BR2(μ-CO)((C6H5)2PCH2P(C6H5)2)2): A BINUCLEAR RHODIUM CARBONYL COMPLEX HAVING AN UNUSUALLY LOW CARBONYL STRETCHING FREQUENCY M. COWIE, M. COWIESearch for more papers by this authorS. K. DWIGHT, S. K. DWIGHTSearch for more papers by this author M. COWIE, M. COWIESearch for more papers by this authorS. K. DWIGHT, S. K. DWIGHTSearch for more papers by this author First published: December 2, 1980 https://doi.org/10.1002/chin.198048067AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue48December 2, 1980 RelatedInformation

ChemInform Abstract: CONFIGURATION‐DEPENDENT RAMAN BANDS OF PHOSPHOLIPID SURFACES. 1. CARBONYL STRETCHING MODES AT THE BILAYER INTERFACE

Chemischer InformationsdienstVolume 11, Issue 46 Physical Organic Chemistry ChemInform Abstract: CONFIGURATION-DEPENDENT RAMAN BANDS OF PHOSPHOLIPID SURFACES. 1. CARBONYL STRETCHING MODES AT THE BILAYER INTERFACE E. BICKNELL-BROWN, E. BICKNELL-BROWNSearch for more papers by this authorK. G. BROWN, K. G. BROWNSearch for more papers by this authorW. B. PERSON, W. B. PERSONSearch for more papers by this author E. BICKNELL-BROWN, E. BICKNELL-BROWNSearch for more papers by this authorK. G. BROWN, K. G. BROWNSearch for more papers by this authorW. B. PERSON, W. B. PERSONSearch for more papers by this author First published: November 18, 1980 https://doi.org/10.1002/chin.198046050Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume11, Issue46November 18, 1980 RelatedInformation

Cyclo(L-prolylglycyl)3 and its sodium, potassium, and calcium ion complexes: a Raman spectroscopic study.

Raman spectra of the cyclic hexapeptide cyclo-(L-prolylglycyl)3 and its Na+, K+, and Ca2+ complexes are reported for the solid state and for samples in solution. Model compounds and N-deuteration were used to aid mode identification. Spectra of the uncomplexed ionophore in solution are consistent with previously proposed solution conformations and permit the identification of spectral lines characteristic of proline-containing peptide bonds in the trans and the cis conformations. Upon cation complexation the prolyl carbonyl stretch bands sharpen and upshift 20-30 cm-1 (to 1690-1700 cm-1). The glycyl carbonyl stretch band is unaffected by Na+ complexation, upshifted approximately 15 cm-1 by K+ complexation, and downshifted approximately 20 cm-1 (to 1619 cm-1) by Ca2+ complexation. Arguments supporting the involvement of prolyl carbonyl groups in cation complexation are noted. Spectra of the Na+ complex of the tetramer cyclo(L-prolylglycyl)4 suggest an asymmetric structure.

ChemInform Abstract: LIGAND EFFECT CONSTANTS: A NEW METHOD FOR PREDICTING THE CARBONYL STRETCHING FREQUENCIES IN TRANSITION‐METAL COMPOUNDS

Chemischer InformationsdienstVolume 10, Issue 50 Physical Organic Chemistry ChemInform Abstract: LIGAND EFFECT CONSTANTS: A NEW METHOD FOR PREDICTING THE CARBONYL STRETCHING FREQUENCIES IN TRANSITION-METAL COMPOUNDS J. A. TIMNEY, J. A. TIMNEYSearch for more papers by this author J. A. TIMNEY, J. A. TIMNEYSearch for more papers by this author First published: December 11, 1979 https://doi.org/10.1002/chin.197950049AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue50December 11, 1979 RelatedInformation

The Correlation between Carbonyl Stretching Frequencies, Force Constant and Formal Bond Order in Carbonyl Complexes

The Correlation between Carbonyl Stretching Frequencies, Force Constant and Formal Bond Order in Carbonyl Complexes

ChemInform Abstract: PROBLEMS IN THE ASSIGNMENT OF BONDING MODE OF BRIDGING CARBONYL GROUPS FROM THE CARBONYL STRETCHING FREQUENCY: THE MOLECULAR STRUCTURE OF BIS‐μ‐(BIS(DIPHENYLARSINO)METHANE)‐μ‐CARBONYL‐BIS(CHLOROPLATINUM(II))

Chemischer InformationsdienstVolume 10, Issue 32 Physical Organic Chemistry ChemInform Abstract: PROBLEMS IN THE ASSIGNMENT OF BONDING MODE OF BRIDGING CARBONYL GROUPS FROM THE CARBONYL STRETCHING FREQUENCY: THE MOLECULAR STRUCTURE OF BIS-μ-(BIS(DIPHENYLARSINO)METHANE)-μ-CARBONYL-BIS(CHLOROPLATINUM(II)) M. P. BROWN, M. P. BROWNSearch for more papers by this authorA. N. KEITH, A. N. KEITHSearch for more papers by this authorLJ. MANOJLOVIC-MUIR, LJ. MANOJLOVIC-MUIRSearch for more papers by this authorK. W. MUIR, K. W. MUIRSearch for more papers by this authorR. J. PUDDEPHATT, R. J. PUDDEPHATTSearch for more papers by this authorK. R. SEDDON, K. R. SEDDONSearch for more papers by this author M. P. BROWN, M. P. BROWNSearch for more papers by this authorA. N. KEITH, A. N. KEITHSearch for more papers by this authorLJ. MANOJLOVIC-MUIR, LJ. MANOJLOVIC-MUIRSearch for more papers by this authorK. W. MUIR, K. W. MUIRSearch for more papers by this authorR. J. PUDDEPHATT, R. J. PUDDEPHATTSearch for more papers by this authorK. R. SEDDON, K. R. SEDDONSearch for more papers by this author First published: August 7, 1979 https://doi.org/10.1002/chin.197932091AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue32August 7, 1979 RelatedInformation

Carbonyl Stretching Frequencies and Electronic Spectra of Rhodium(I) Monocarbonyl Complexes

Carbonyl Stretching Frequencies and Electronic Spectra of Rhodium(I) Monocarbonyl Complexes

ChemInform Abstract: SUBSTITUENT EFFECTS IN INFRARED SPECTROSCOPY. PART 5. CARBONYL STRETCHING FREQUENCY IN META‐ AND PARA‐SUBSTITUTED AROMATIC CARBONYL COMPOUNDS

Chemischer InformationsdienstVolume 10, Issue 20 Physical Organic Chemistry ChemInform Abstract: SUBSTITUENT EFFECTS IN INFRARED SPECTROSCOPY. PART 5. CARBONYL STRETCHING FREQUENCY IN META- AND PARA-SUBSTITUTED AROMATIC CARBONYL COMPOUNDS C. LAURENCE, C. LAURENCESearch for more papers by this authorM. BERTHELOT, M. BERTHELOTSearch for more papers by this author C. LAURENCE, C. LAURENCESearch for more papers by this authorM. BERTHELOT, M. BERTHELOTSearch for more papers by this author First published: May 15, 1979 https://doi.org/10.1002/chin.197920051Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue20May 15, 1979 RelatedInformation

Laser excited resonance fluorescence in formaldehyde

The 3375 Å line of the Kr+ laser has been used to excite a single rovibronic transition of the ?1A2–?1A1 system of formaldehyde. Fluorescence from the upper level to the ground electronic state forms vibrational progressions in the carbonyl stretch (ν2″), the symmetric in plane bend (ν3″) and twice the out of plane bend (2ν4″), extending over 10 000 cm−1 to the red of the exciting line. The rotational structure has been resolved and effective rotational A constants have been obtained. Vibrational constants and anharmonicities have been calculated.

Infrared spectroscopy of polynucleotides in the carbonyl region in H2O solution: A.U systems.

Strong absorbance of water at 1645 cm-1 has previously prevented dependable observation of infrared spectra of H2O solutions in the carbonyl region. We have obtained reliable spectra in pure water and in alcohol-water mixtures in this region and used them to study A.U polynucleotide interaction. Spectra in pure water were obtained by computer subtraction of solvent from that of solution measured in short path length cells. Mixed solvents, by diluting the water, permit use of longer cells and standard double-beam compensation methods. Poly(adenylic acid) in H20 solution has a strong NH2 deformation band at 1659 cm-1 coupled to an A ring vibration at 1605 cm-1. Poly(uridylic acid) has a broad band at approximately 1695 cm-1, predominantly C2 carbonyl stretch, an unresolved CR carbonyl band (probably near 1660 cm-1), and a ring vibration at approximately 1636 cm-1. The large changes these spectra undergo when helical structures are formed are discussed and compared with changes observed in D2O.

Carbonyl Stretching Frequencies in Some Acylhalides and Monothiocarboxylic Acids

Carbonyl Stretching Frequencies in Some Acylhalides and Monothiocarboxylic Acids

The carbonyl stretch of furfural: Fermi resonance and rotational isomerism

The i.r. region of the carbonyl stretch of furfural is interpreted in terms of Fermi resonance and rotational isomerism. The Fermi doublets for each rotamer are assigned and the unperturbed frequencies and Fermi coupling coefficients W, are evaluated by the method of solvent variation.

ChemInform Abstract: CALCULATION OF CARBONYL STRETCHING AND INTERACTION FORCE CONSTANTS FOR MONO(TETRACARBONYLCOBALT) DERIVATIVES OF TIN(IV) BASED ON THE APPROXIMATION OF PAUL

Chemischer InformationsdienstVolume 8, Issue 3 Organoelement Compounds ChemInform Abstract: CALCULATION OF CARBONYL STRETCHING AND INTERACTION FORCE CONSTANTS FOR MONO(TETRACARBONYLCOBALT) DERIVATIVES OF TIN(IV) BASED ON THE APPROXIMATION OF PAUL L. F. WUYTS, L. F. WUYTSSearch for more papers by this authorG. P. VAN DER KELEN, G. P. VAN DER KELENSearch for more papers by this author L. F. WUYTS, L. F. WUYTSSearch for more papers by this authorG. P. VAN DER KELEN, G. P. VAN DER KELENSearch for more papers by this author First published: January 18, 1977 https://doi.org/10.1002/chin.197703314Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue3January 18, 1977 RelatedInformation

Ion complexation in nonactin, monactin, and dinactin: a Raman spectroscopic study.

AbstractThe ability of the macrotetrolide nactins to complex selectivity with a wide variety of cations makes these ionophorous antibiotics important model systems for the study of biologic ionic transport. We report a Raman spectroscopic investigation of the Na+, K+, Rb+, Cs+, Tl+, NH4+, NH3OH+, C(NH2)3+, and Ba++ complexes of nonactin, monactin, and dinactin in 4:1 (v/v) CH3OH/CHCl3 and in the solid state. The nactins display characteristic spectral changes upon complexation, some of which are specific for a given cation. In the K+, Rb+, Cs+, NH3OH+, and C(NH2)3+ complexes, which are apparently isosteric, the ester carbonyl stretch frequency is found to be linearly proportional to the cation–carbonyl electrostatic interaction energy, as calculated from a simplified model. Deviations for the Na+, NH4+, Tl+, and Ba++ complexes are interpreted as arising from additional nonelectrostatic interactions. Additional information is obtained from other spectral regions and from measurements of depolarization ratios. Spectra of the nactin complexes differ from each other more in the solid state than in solution, reflecting the effects of crystalline contact forces.

Solvent and substituent effects in aromatic carbonyl compounds: the lowest triplet states of xanthone and xanthone-18O1

The phosphorescence of xanthone and xanthone-18O1 in ethanol-ether-isopentane (EPA) and in 3-methylpentane (3-MP) has been studied between 12 and 125 K. The dual phosphorescence in this ketone is attributed to the existence of two different ground-state conformations, each of which has a characteristic triplet state. The longer-lived phosphorescence is assigned to a more planar conformation than the short-lived species. Because a progression based on the carbonyl stretch frequency appears in both short and long-lived components, we assign some n, π* character to both forms. Thermally populated fluorescence from the lowest 1(n, π*) state of xanthone is also reported for the first time.

ChemInform Abstract: DERIVATIVES OF MANGANESE CARBONYL WITH BIS(DIPHENYLPHOSPHINO)METHANE AND BIS(DIPHENYLARSINO)METHANE

AbstractDie 1:1‐molare Umsetzung von Dekacarbonyldirnangan (I) mit den Titelliganden führt zu den ligand‐verbrückten, diamagnetischen Mn‐Mn‐Komplexen (II).

Electrostatic and Steric Effects in the Selective Complexation of Cations in Nonactin

The ester carbonyl stretch frequencies of complexes of the macrotetrolide nonactin with Na(+), K(+), Rb(+), Cs(+), Tl(+), NH(4)(+), NH(3)OH(+), and (NH(2))(2)CNH(2)(+) have been measured. For the larger alkali cations and the polyatomic cations, the ester carbonyl stretch frequency is linearly proportional to the cation-ester carbonyl electrostatic interaction energy. This constitutes direct evidence that the cation-nonactin interaction is primarily electrostatic, rather than mechanical (steric).

Polarized Raman scattering from a helical biopolymer

Polarized Raman spectra are reported for thin films of oriented α−helices of poly−γ−benzyl−l−glutamate. All four independent spectra were measured using 180° scattering at near−normal incidence and 90° scattering at grazing incidence. Polarization ratios are analyzed in terms of scattering from a helical array of units with a Raman tensor of axial symmetry and definite orientation depending on the mode involved. The method is applied to three stretching modes: the amide I, the ester carbonyl stretch, and the N−H stretch. Orientation angles of the principal axis relative to the helix axis are found to be 39°±2°, 55°±3°, and 28°±3°, respectively, in good agreement with the results of infrared dichroism.